Author: Rodrigo Arrangoiz MS, MD, FACS, FSSO

My name is Rodrigo Arrangoiz I am a breast surgeon/ thyroid surgeon / parathyroid surgeon / head and neck surgeon / surgical oncologist that works at Center for Advanced Surgical Oncology in Miami, Florida. I was trained as a surgeon at Michigan State University from (2005 to 2010) where I was a chief resident in 2010. My surgical oncology and head and neck training was performed at the Fox Chase Cancer Center in Philadelphia from 2010 to 2012. At the same time I underwent a masters in science (Clinical research for health professionals) at the University of Drexel. Through the International Federation of Head and Neck Societies / Memorial Sloan Kettering Cancer Center I performed a two year head and neck surgery and oncology / endocrine fellowship that ended in 2016. Mi nombre es Rodrigo Arrangoiz, soy cirujano oncólogo / cirujano de tumores de cabeza y cuello / cirujano endocrino que trabaja Center for Advanced Surgical Oncology en Miami, Florida. Fui entrenado como cirujano en Michigan State University (2005 a 2010 ) donde fui jefe de residentes en 2010. Mi formación en oncología quirúrgica y e n tumores de cabeza y cuello se realizó en el Fox Chase Cancer Center en Filadelfia de 2010 a 2012. Al mismo tiempo, me sometí a una maestría en ciencias (investigación clínica para profesionales de la salud) en la Universidad de Drexel. A través de la Federación Internacional de Sociedades de Cabeza y Cuello / Memorial Sloan Kettering Cancer Center realicé una sub especialidad en cirugía de cabeza y cuello / cirugia endocrina de dos años que terminó en 2016.

Breast Cancer Recurrences: Management

Rodrigo Arrangoiz MS, MD, FACS, FSSO
  • In general, local chest wall or nodal recurrences should be excised if feasible, and then possibly treated with systemic therapy
  • The role of chemotherapy following complete excision of isolated locoregional recurrence:
    • Was examined in the CALOR trial with the final analyses of this trial:
      • Demonstrating a 10-year disease-free survival benefit:
        • For patients with the addition of chemotherapy in ER negative recurrences:
          • But no statistically significant benefit for ER positive recurrences
  • Re-irradiation with or without hyperthermia has also been examined:
    • Vernon et al. included multiple prospective randomized trials comparing radiation alone (RT) versus hyperthermia (HT):
      • The local complete response was:
        • 59% in the combined group and 41% in the RT alone group
    • A large meta-analysis by Datta et al. combined 34 studies (8 two-arm, and 26 single-arm):
      • The complete response (CR) rate reported for the combined RT + HT for the two-arm studies was 60% vs. 38% for RT alone
  • Concurrent chemotherapy with radiation therapy has also been evaluated, in particular with chemosensitizers such as capecitabine:
    • Zagar et al. report that a combination of mild hyperthermia with a thermally sensitive doxorubicin containing liposome was safe when treating for patients with chest wall recurrences of breast cancer
  • References
    • Wapnir IL, Price KN, Anderson SJ, et al. Efficacy of chemotherapy for ER-negative and ER-positive isolated locoregional recurrence of breast cancer: final analysis of the CALOR Trial. J Clin Oncol. 2018;36:1073-9.
    • Vernon CC, Hand JW, Field SB, et al. Radiotherapy with or without hyperthermia in the treatment of superficial localized breast cancer: results from five randomized controlled trials. International Collaborative Hyperthermia Group. Int J Radiat Oncol Biol Phys. 1996;35(4):731-744.
    • Datta NR, Puric E, Klingbiel D, Gomez S, Bodis S. Hyperthermia and radiation therapy in locoregional recurrent breast cancers: a systematic review and meta-analysis. Int J Radiat Oncol Biol Phys. 2016;94(5):1073-1087.
    • Zagar TM, Higgins KA, Miles EF, et al. Durable palliation of breast cancer chest wall recurrence with radiation therapy, hyperthermia, and chemotherapy. Radiother Oncol. 2010;97(3):535-540.
    • Zagar TM, Oleson JR, Vujaskovic Z, et al. Hyperthermia combined with radiation therapy for superficial breast cancer and chest wall recurrence: a review of the randomised data. Int J Hyperthermia. 2010; 26(7): 612-617.
    • Zagar TM, Vujaskovic Z, Formenti S, et al. Two phase I dose-escalation/pharmacokinetics studies of low temperature liposomal doxorubicin (LTLD) and mild local hyperthermia in heavily pretreated patients with local regionally recurrent breast cancer. Int J Hyperthermia. 2014 Aug; 30(5): 285-294.

Thyroid Function Testing in Hypothyroidism

Rodrigo Arrangoiz MS, MD, FACS, FSSO
  • The initial test recommended in the evaluation of hypothyroidism is:
    • A serum TSH concentration if the patient has any of the signs or symptoms of a hypothyroid syndrome or any of the risk factors shown in table
  • The measurement of a TSH:
    • Is a very sensitive and specific method to diagnose hypothyroidism
    • It is almost always elevated in primary hypothyroidism:
      • The TSH rise occurs before the decreases of serum T4 and / or T3 levels
    • However, measurement of TSH is not a good initial test for secondary hypothyroidism:
      • Thus should not be used to assess the thyroid status of a patient with known or suspected hypothalamic or pituitary disease, or in severe nonthyroidal illness
    • Serum TSH is also difficult to use when thyroid hormone levels are in flux
    • If thyroid hormone replacement is not initiated after thyroidectomy:
      • TSH rises to > 30 mIU/L within 22 days in 95% of individuals
  • An algorithm for the evaluation of hypothyroidism in an individual with signs and / or symptoms suggestive of the disease is presented in Figure
  • If the serum TSH is within the normal range:
    • The patient is biochemically euthyroid and no further evaluation is necessary
  • If the TSH is > 10 mIU/L:
    • Thyroid hormone replacement should be initiated:
      • An exception is during recovery from an acute illness or in subacute thyroiditis:
        • When the TSH may be transiently elevated before its normalization
  • If the TSH is elevated above the reference range but still < 10 mIU/L:
    • It is recommended that the TSH with an estimate of free T4 and a serum TPO Ab level:
      • Be repeated in 1 month
    • If the TSH is elevated on repeat assessment and the free T4 (or FT4I) is decreased:
      • It is recommended to start thyroid hormone replacement therapy for the treatment of overt hypothyroidism
  • Measurement of total or free T3 levels is not indicated in the evaluation of hypothyroidism:
    • Because T3 levels are maintained within the reference range:
      • In mild to moderate hypothyroidism:
        • Due to increased conversion of T4 to T3:
          • Via the increased activity of 5′deiodinase
  • Subclinical Hypothyroidism:
    • Subclinical hypothyroidism is defined as:
      • An elevated serum TSH concentration with a normal measure of free T4 (either as FT4 or FT4I)
    • Of the U.S. population over age 80 years:
      • Approximately 15% have a serum TSH level > 4.5 mIU/L:
        • Particularly among those with serum thyroid antibody positivity
    • The optimal management of subclinical hypothyroidism has been a matter of controversy:
      • Because the TSH will normalize in approximately one-third of adults over a 3- to 4-year period:
        • It is important to identify those who will have persistent disease and / or those who may benefit from thyroid hormone replacement
    • Some small, well-controlled studies:
      • Have suggested a benefit toward improved well-being and a reduction in cholesterol levels:
        • In subclinically hypothyroid individuals treated with thyroid hormone
      • The benefit of reducing cardiovascular risk is primarily seen in middle-aged patients:
        • With less improvement among older patients
    • In general, the decision to treat patients with subclinical hypothyroidism:
      • Depends on the presence of signs or symptoms of hypothyroidism, or the increased risk of progression to overt hypothyroidism:
        • As indicated by a positive risk factor, such as:
          • Sonographic evidence of thyroiditis
          • Elevated serum antithyroid antibody titers
          • The presence of other high-risk conditions such as:
            • Cardiovascular disease
            • Pregnancy
            • Infertility
    • If the individual is asymptomatic:
      • The most conservative approach is to follow the patient clinically and repeat the TSH in 6 to 12 months or earlier as directed by signs or symptoms (Figure)
      • It would also be reasonable to obtain additional data to determine the risk of progression to overt hypothyroidism, including:
        • Inquiring about a family history of autoimmune thyroid disease
        • Performing a thyroid ultrasound to assess for thyroiditis
        • Obtaining a serum TPO Ab titer
      • In one study, women with mild subclinical hypothyroidism and serum thyroid autoimmunity followed for 4 years:
        • Had a 5% per year risk of developing biochemical hypothyroidism
  • Serum Thyroid Antibodies in Hypothyroidism:
    • Measurement of serum antithyroid antibodies in the differential diagnosis of primary hypothyroidism:
      • Should be interpreted in the context of the clinical findings
    • TPO Ab or TgAb is positive:
      • In most patients with autoimmune thyroiditis (Hashimoto’s thyroiditis)
        • It is not required but confirms the diagnosis:
          • Those with high titers are likely to progress more rapidly to overt hypothyroidism
    • Elevated serum TPO Ab and TgAb:
      • Can be detected after the release of thyroid antigens:
        • In patients with silent subacute thyroiditis:
          • Such as postpartum thyroiditis
  • Thyroid Imaging in Hypothyroidism:
    • Thyroid ultrasound in Hashimoto’s demonstrates:
      • A characteristic irregular texture and is often associated with diffuse enlargement
    • Blood flow, as assessed by Doppler:
      • Is reduced in subacute thyroiditis:
        • But it is difficult to distinguish reduced flow from normal
    • Radionuclide imaging of the thyroid:
      • Is almost never helpful for the diagnosis of hypothyroidism
    • Thus thyroid ultrasound and / or radionuclide imaging:
      • Should be performed only to evaluate suspicious structural abnormalities:
        • Such as a palpable thyroid nodule in the hypothyroid patient
    • Although controversial, there is an epidemiologic association of:
      • Concurrently elevated serum TSH concentrations in thyroiditis with an increased risk of thyroid malignancy
    • It has been suggested that clinicians use sonography to evaluate patients with thyroiditis, Hashimoto’s thyroiditis, and Graves’ disease:
      • To detect thyroid nodules:
        • Which would then require biopsy based on ultrasound features
  • Treatment of Hypothyroidism:
    • Hypothyroidism is treated with thyroid hormone replacement:
      • Usually in the form of oral T4 (levothyroxine)
    • In individuals with little or no endogenous thyroid hormone production:
      • The usual requirement is 1.6 mcg/kg/day
    • Because 80% of circulating T3 is derived from T4:
      • T4 monotherapy is adequate in most patients for thyroid hormone replacement
    • Some patients, however, have persistent symptoms of hypothyroidism while on biochemically adequate levothyroxine replacement and prefer the use of T4 / T3 combined products:
      • Such as desiccated thyroid
    • The American Thyroid Association guidelines;
      • State that there is a lack of high-quality controlled long-term outcome data:
        • To routinely support the use of desiccated thyroid extract, combination synthetic T4 / T3, or T3 monotherapy:
          • Over levothyroxine therapy
  • In patients with primary hypothyroidism:
    • Levothyroxine dose adjustments should be done based on a serum TSH measured 4 to 6 weeks after initiating the medication:
      • Due to the long half-life of levothyroxine, which is 7 to 10 days
    • The goal of treatment is a serum TSH level around the middle of the normal range:
      • For otherwise healthy individuals with primary hypothyroidism
    • And to suppressed TSH or a TSH level at the low end of the normal range is targeted for most patients with differentiated thyroid cancer

Chest Wall Recurrence after Mastectomy – Calor Trial

Rodrigo Arrangoiz MS, MD, FACS, FSSO
  • Patients with chest wall recurrence:
    • Are at high risk for:
      • Concurrent systemic recurrences:
        • Therefore, obtaining systemic staging and receptor information on the recurrence should be the first consideration
  • Often, there may be extensive local regional involvement in several areas along the chest wall and in the nodal regions
  • According to National Comprehensive Cancer Network guidelines:
    • Systemic staging generally consists of either a PET/CT scan or a CT of the chest, abdomen, and pelvis, as well as a bone scan
  • Surgical excision with negative margins:
    • Followed by comprehensive chest wall and nodal radiotherapy may be indicated in the absence of widespread systemic disease
  • These patients should be managed by a multidisciplinary team, including:
    • The surgical oncologist, medical oncologists, radiologists, pathologists, and potentially a plastic surgeon
  • Patients may or may not benefit from chemotherapy:
    • In the CALOR trial:
      • Chemotherapy was found to benefit patients with resected ER negative isolated locoregional recurrence:
        • But not ER positive isolated local regional recurrence
  • References

Evaluation of Hypothyroidism

Rodrigo Arrangoiz MS, MD, FACS, FSSO
  • Signs and Symptoms of Hypothyroidism:
    • Commons signs and symptoms of hypothyroidism are mostly nonspecific, and some patients may not display any signs or symptoms
    • Symptoms may be insidious, and in the elderly and middle-aged women:
      • Nonspecific complaints may be interpreted as signs of normal aging or depression
    • Symptoms of hypothyroidism depend on the degree and duration of the disease:
      • But most frequently include:
        • Weight gain
        • Fatigue
        • Constipation
        • Menstrual irregularities / infertility
    • General signs and symptoms of hypothyroidism:
      • Weight gain
      • Fatigue
      • Cold Intolerance
      • Hyponatremia
      • Hypothermia
      • Increased body mass index
    • Skin:
      • Dry and coarse skin
      • Dry and coarse hair
      • Pretibial myxedema (non pitting edema)
      • Hair loss
    • Head and Neck:
      • Hoarse voice
      • Enlarged tongue
      • Periorbital edema
      • Goiter
    • Gastrointestinal:
      • Constipation
      • Reduced esophageal motility
      • Nonalcoholic fatty liver
    • Musculoskeletal:
      • Myalgia
      • Muscle cramps
      • Muscle weakness
      • Carpel tunnel syndrome
      • Elevation of serum creatine phosphokinase
      • Hoffman’s syndrome:
        • Rare form of hypothyroid myopathy:
          • Characterized by pseudohypertrophy (increased muscle mass) and proximal muscle weakness:
            • Particularly in the legs
    • Nervous system:
      • Depression
      • Impaired concentration
      • Memory loss
      • Changes in vision, hearing, and taste
      • Dementia
      • Impaired congitive function
      • Neurophathy
      • Cochlear dysfunction
      • Decreased gustartory and olfactory sensitivity
      • Delayed relaxation of tendon reflexes
    • Cardiovascular:
      • Fatigue on exertion
      • Shortness of breath
      • Bradycardia
      • Diastolic hypertension
      • Dyslipidemia
      • Electrocardiogram changes
      • Hyperlipidemia
      • Pericardial effusion
      • Congestive heart failure
    • Reproductive:
      • Irregular menstrual periods
      • Amenorrhea
      • Galactorrhea:
        • If accompiend by elevated prolactin levels
      • Infertility
      • Miscarriage
    • Hematological:
      • Bleeding
      • Fatigue
      • Mild anemia
      • Acquired von Willebrand disease
      • Decreased protein C and S
      • Increased red blood cell distribution width
      • Increased mean platelet volume
  • Etiologies of Hypothyroidism:
    • The most common etiologies of decreased serum thyroid hormone concentrations are those associated with primary hypothyroidism:
      • Which is defined as underproduction of thyroid hormone at the thyroid gland
    • Excluding postsurgical and postablative hypothyroidism:
      • The most common cause of adult hypothyroidism worldwide is:
        • Hashimoto’s thyroiditis
    • Causes of hypothyroidism associated with secondary and tertiary disease:
      • When hypothyroidism arises from pituitary and hypothalamic insults, respectively:
        • Are much less common
  • It is important that hypothyroidism arising from Hashimoto’s thyroiditis:
    • Be distinguished from transient forms of hypothyroidism:
      • Such as excess iodine exposure
      • The hypothyroid phase of subacute thyroiditis
    • Hypothyroidism arising from Hashimoto’s thyroiditis:
      • Is an indication for lifelong thyroid hormone replacement:
        • The transient forms of hypothyroidism may not necessarily require this
  • The most common forms of subacute thyroiditis are:
    • Postpartum thyroiditis
    • Painful subacute thyroiditis
    • Painless subacute or silent thyroiditis
  • All forms of subacute thyroiditis:
    • Are characterized by the triphasic pattern of transient thyrotoxicosis (i.e., 1 to 3 months):
      • Followed by transient hypothyroidism (i.e., lasting up to 6 months):
        • With the eventual return to the euthyroid state:
          • Although not all patients will experience all phases
    • Postpartum thyroiditis:
      • Occurs in the few months after a:
        • Miscarriage, therapeutic abortion, or delivery
    • Subacute painful thyroiditis:
      • Is associated with:
        • An enlarged and tender thyroid gland
        • Variably presents with flulike symptoms:
          • High fever, myalgia, and a high serum erythrocyte sedimentation rate (ESR)
    • Painless or silent lymphocytic subacute thyroiditis:
      • Is associated with an enlarged thyroid gland
    • All three types of subacute thyroiditis:
      • Can be diagnosed by a:
        • Very low radioactive iodine uptake
    • In most cases, the hypothyroid phase of subacute thyroiditis does not require treatment with thyroid hormone replacement:
      • Unless the patient is symptomatic or the hypothyroidism is biochemically severe
Rodrigo Arrangoiz MS, MD, FACS, FSSO
  • The long-awaited B51 has been published. A study that opens door, but doesn’t close them all. Should we irradiate nodal areas in cN1 patients who achieve ypN0 after NAC?
  • Evidence might be solid to omit RNI in HER2+ patients with good response. This group appears to be the most promising.
  • The triple-negative cohort shows a puzzling signal: higher risk with irradiation. Statistical noise? Selection bias? Serendipity?
  • In pure luminal cases—5% in practice but only 20% in the trial there’s a trend toward benefit with RNI.
  • Limited follow-up, low representation, and no data on grade or LVI make it hard to change practice based on this evidence.
  • Also, I wonder if this was actually two studies in one:
    • In mastectomy, it’s all or nothing—irradiate everything or nothing at all.
    • In breast-conserving surgery, it’s about adding or omitting RNI from standard treatment.
  • B51 is a step toward personalized treatment but not the final word.
  • Sometimes, less is not less—but more.
  • Yet omission must always be thoughtful.

Morbidity of Lymph Node Surgery in Melanoma

Rodrigo Arrangoiz MS, MD, FACS, FSSO
  • Complications associated with sentinel lymph node biopsy (SLNB) for melanoma:
    • Were evaluated in 2,120 patients in an analysis of data from the Sunbelt Melanoma Trial:
      • Overall, 96 (4.6%) of the patients developed major or minor complications associated with SLNB:
        • Whereas 103 (23.3%) of 444 patients experienced complications associated with SLNB plus completion lymph node dissection
      • The authors concluded that:
        • SLNB alone is associated with significantly less morbidity compared to SLNB plus completion lymph node dissection
    • Similar to the Sunbelt Melanoma Trial, in MSLT-1:
      • SLNB did not significantly add to the morbidity of melanoma surgery when compared to wide excision of the primary melanoma alone
  • Formal lymphadenectomy is associated with higher complication rates than SLNB, and includes:
    • Seroma
    • Wound infection
    • Cellulitis
    • Lymphedema
    • Skin flap problems:
      • That may on occasion require surgical revision
  • Complication rates are higher in the:
    • Inguinal region than in the axilla or neck:
      • Cormier et al. prospectively followed 53 patients at MD Anderson who underwent inguinal lymphadenectomy for melanoma:
        • Using liberal objective criteria, investigators found the:
          • Acute wound complication rate to be 77.4% with a wound infection rate of 54.7% and a wound dehiscence rate of 52.8%
        • In multivariate analysis, only body mass index was found to be associated with an increase in complications
    • The infection rate reported after lymphadenectomy in MSLT-1 was 12%:
      • They noted that lymphedema rates varied significantly depending on the lymph nodes basins that were dissected:
        • 9.0% for axillary lymphadenectomy vs. 26.6% for inguinal lymphadenectomy)
  • Lymphedema is among the most serious long-term complications of formal lymphadenectomy:
    • Inguinal lymphadenectomy associated lymphedema:
      • Was not altered significantly by the addition of a deep groin dissection
    • In addition, the number of lymph nodes removed:
      • Did not appear to alter the lymphedema rate significantly
  • In the study by Cormier et al:
    • The lymphedema rate at 3 months was 85% using qualitative measures and 45% by quantitative measures for patients who underwent inguinal lymphadenectomy
  • Lower extremity edema after groin dissection:
    • Can be decreased by preventive measures, including:
      • Perioperative antibiotics
      • Elastic stockings
      • Leg elevation exercises
      • On occasion, diuretics
    • Even with preventive measures, patients should be counseled that lymphedema can still develop
  • Nonetheless, prophylactic measures are important:
    • Because reversing the progression of lymphedema is difficult
  • The complication rate for axillary lymph node dissections is lower than that for inguinal dissection:
    • The most frequent complication is wound seroma:
      • Varying from 3% to 23%
    • Other common complications include:
      • Cellulitis and lymphedema (approximately 10%)

UPDATE from the American Association of Clinical Endocrinology 2025 Annual Meeting

Rodrigo Arrangoiz MS, MD, FACS, FSSO
  • Radiofrequency Ablation will be a viable treatment for Papillary Thyroid Carcinoma
    For low-risk patients with papillary thyroid carcinoma interested in something other than surgery or surveillance, radiofrequency ablation may be an option.
  • At the AACE Annual Scientific and Clinical Conference the experience of the Thyroid Institute of Southern California in Newport Beach was presented.
  • A single-arm study of 24 patients with papillary thyroid carcinoma who underwent one session of radiofrequency ablation.
  • All 24 patients declined surgery and refused the Watch & Wait approach to treating microcarcinomas and did not have a tumor more than 2 cm in its greatest dimension lymph node metastasis or an aggressive subtype of tumor.
  • Papillary thyroid carcinoma is one of the most common thyroid cancers.
  • Traditional management has been surgery or active surveillance.
  • Minimally invasive therapy such as radiofrequency ablation can be an emerging therapy for our patients.
  • The objective of the study was to evaluate radiofrequency ablation and compare it to active surveillance.
  • Eleven patients had a T1a tumor (< 1 cm) 12 had a T1b tumor (1 cm to < 2 cm) and one had a T2 tumor (2 cm to < 4 cm), and four patients had a BRAF mutation.
  • At 12 months tumor size was reduced by more than 80% in those with T1a tumors (86%) and those with T1b tumors (82.5%).
  • Percent volume reduction at 12 months was slightly greater in patients with a BRAF mutation.
  • Maybe it’s operator-dependent they may use more aggressive radiofrequency in those regions.
  • The percent volume reduction at 12 months was 64.2% in patients with T1a tumors and 78% in patients with T1b tumors.
  • Among those with T1a tumors those with a BRAF mutation had an 86.3% reduction and those without one had a 72.31% reduction.
  • These results are quite pleasing for first-year data. By contrast in a 2020 study of 50 patients who were under active surveillance 30 of them eventually had surgery.
  • Radiofrequency is a very viable option for low-risk papillary thyroid carcinomas in those who decline surgery or surveillance with very precise selection of your patient.
  • Despite the significant tumor reduction has been seen here over 12 months the physicians are going to look at the 2, 3 and 4-year data because this looks very promising.
  • Careful screening of these patients will be very important.
  • This is a very good alternative to active surveillance because of significant patient anxiety.
  • Further studies are necessary & needed.

  • Nikravan SP. Radiofrequency ablation of T1a and T1b papillary thyroid carcinoma: A North American outpatient endocrinologist experience. Presented at AACE Annual Scientific and Clinical Conference; May 2025; Orlando.

Neck Dissection for Cutaneous Melanoma

Rodrigo Arrangoiz MS, MD, FACS, FSSO
  • Lymph node metastases from melanomas in the head and neck were previously believed to follow a predictable pattern:
    • However, it is established that lymphatic drainage from melanomas of the head and neck can be multidirectional and unpredictable
  • SLNB may be misdirected in as many as 59% of patients:
    • If the operation is based on classic anatomical studies without preoperative lymphoscintigraphy:
      • These findings strongly support the use of lymphoscintigraphy in patients with melanomas in the head and neck
  • My approach for patients with melanoma in the head and neck region and clinically involved nodes is:
    • Wide excision of the primary lesion with either modified radical neck dissection or selective neck dissection
  • Melanomas arising on the scalp or face anterior to the pinna of the ear and superior to the commissure of the lip:
    • Can metastasize to intraparotid lymph nodes because these nodes are contiguous with the cervical nodes:
      • When intraparotid nodes are clinically involved, it is advisable to combine neck dissection with parotid lymph node dissection

Metastatic Melanoma of Unknown Primary Site

Rodrigo Arrangoiz MS, MD, FACS, FSSO
  • Approximately 1% to 8% of patients with melanoma:
    • Present with metastatic disease from melanoma of unknown primary (MUP) site
  • The most common presentation is:
    • In the axillary lymph node basin (> 50%):
      • Followed by the cervical lymph node basin
  • Various reasons have been proposed for the phenomenon of MUP site:
    • Anbari et al. suggested the following possibilities for primary lesions:
      • An unrecognized melanoma
      • A treated melanoma that had been initially misdiagnosed
      • A spontaneously regressed melanoma
      • Malignant transformation of a melanocyte that had traveled to a metastatic location
  • For metastatic melanoma to be classified as MUP site:
    • The histologic diagnosis must be confirmed
    • Previous biopsies and / or excisions, if any, should be evaluated for a possible diagnosis of melanoma
    • Less common primary sites for melanoma should be thoroughly evaluated
  • A thorough history may also identify prior lesion that was excised or destroyed:
    • But never pathologically examined
  • If the metastatic lesion is to a lymph node basin:
    • The drainage areas of that basin should be rigorously examined
    • Furthermore, patients should undergo staging evaluation with:
      • CT of the chest, abdomen, and pelvis (also including neck CT if anatomically appropriate), and MRI of the brain
      • PET / CT can also be considered, particularly in the setting of extremity soft tissue metastasis associated with unknown primary
  • Several studies have compared the survival of these patients to similar cohorts having equivalent nodal status and a known primary site:
    • Although patients with unknown primary tumors were historically believed to have worse prognoses:
      • Recent studies have contradicted earlier findings by demonstrating that patients with MUP have a natural history that is similar to (if not better than) the survival of many patients with stage III disease:
        • Given their survival profile, such patients with nodal disease should be staged as stage III and treated like stage III patients with a known primary melanoma, including consideration for stage III clinical trials

Dissection of the Iliac and Obturator Nodes in Melanoma

Rodrigo Arrangoiz MS, MD, FACS, FSSO
  • General:
    • I generally perform a deep groin dissection (dissection of the iliac and obturator nodes) for the following indications:
      • Known involvement of the nodes revealed by preoperative imaging studies
      • More than three grossly positive nodes in the superficial lymph node dissection specimen
      • Metastatic disease in Cloquet node:
        • If performed
  • Incision:
    • To gain access to the deep nodes, we extend the skin incision superiorly if performed concomitantly with a superficial groin dissection
    • If a deep groin dissection only is to be performed:
      • I generally use a dedicated right lower quadrant incision
  • Lymph Node Dissection:
    • The external oblique muscle:
      • Is split from a point superomedial to the anterior superior iliac spine to the lateral border of the rectus sheath
    • The internal oblique and transversus abdominis muscles:
      • Are divided, and the peritoneum is retracted superiorly
    • An alternative approach:
      • Sometimes used when extensive disease populates this region:
        • Is to split the inguinal ligament vertically:
          • Medial to the femoral vein
    • The ureter is exposed:
      • As it courses over the iliac artery
    • The inferior epigastric artery and vein are divided, if necessary
    • The bifurcation of the common iliac artery marks the cephalad extent of the dissection:
      • All nodes are taken along the external iliac artery to the inguinal ligament caudally
    • Nodes overlying the external iliac vein:
      • Are dissected to the point at which the internal iliac vein courses under the internal iliac artery
    • The plane of the peritoneum is traced along the wall of the bladder:
      • The fatty tissues and lymph nodes are dissected off the perivesical fat starting at the internal iliac artery
    • Dissection is completed on the medial wall of the external iliac vein, and the nodal chain is further separated from the pelvic fascia until the obturator nerve is seen
    • Obturator nodes:
      • Are located in the space between the external iliac vein and the obturator nerve (in an anteroposterior direction) and between the internal iliac artery and the obturator foramen (in a cephalad–caudad direction)
    • The obturator artery and vein usually need not be disturbed
  • Wound Closure:
    • The transversus abdominis, internal oblique, and external oblique muscles:
      • May be closed with running sutures
    • The inguinal ligament, if previously divided:
      • Is approximated with interrupted nonabsorbable sutures to Cooper ligament medially and to the iliac fascia lateral to the femoral vessels
    • A closed suction drain is placed in the deep pelvic space exiting through a separate small incision
  • Postoperative Management:
    • Suction drainage is continued until output is less than 20 mL to 30 mL per day for 2 consecutive days
    • The pelvic drain is usually removed prior to hospital discharge
    • Ambulation is encouraged the day after surgery
    • Patients are hospitalized postoperatively for expectant management of potential ileus after deep pelvic surgery and for pain control, usually for a duration of 2 to 3 days