Medullary Thyroid Cancer (MTC)

• Introduction:
  • Medullary thyroid cancer (MTC):
    • Is a neuroendocrine tumor of the parafollicular or C cells of the thyroid gland:
      • MTC accounts for:
        • Approximately 1% to 2% of all thyroid cancers in the United States:
      • The production of calcitonin:
        • Is a characteristic feature of this tumor
    • Most medullary thyroid carcinomas:
      • Are sporadic (75% to 80%):
        • However:
          • Approximately 20% to 25%  are familial:
            • As part of the multiple endocrine neoplasia type 2 (MEN2) syndrome

• Clinical Presentation:
  • Sporadic MTC:
    • Sporadic medullary thyroid cancer (MTC):
      • Accounts for approximately 75% of all cases of the disease:
        • The typical age of presentation:
          • Is in the fourth and sixth decades of life
  • Symptoms and signs:
    • The most common presentation of sporadic MTC:
      • Is that of a solitary thyroid nodule:
        • Which occurs in 75% to 95% percent of patients
    • The C cells or parafoliccular cells are predominantly located in the upper portion of each thyroid lobe:
      • Thus:
        • Most tumors are located in this region
    • In most patients with MTC:
      • The disease has already metastasized at the time of diagnosis:
        • Approximately 70% of patients have clinically detectable cervical lymph node involvement
      • Up to 15% of patients with MTC:
        • Have symptoms of upper aerodigestive tract compression or invasion:
          • Such as dysphagia or hoarseness
      • Approximately 5% to 10%:
        • Have distant metastatic disease:
          • Distant metastases may occur in the:
            • Liver, lung, bones, and, less often, brain and skin
          • Nodal metastases:
            • Are more common in patients with multifocal disease:
              • However, as calcitonin screening results in the identification of more “micro” medullary cancers:
                • The number of patients with metastases at presentation appears to be decreasing
              • Calcitonin screening for MTC in patients with thyroid nodules is controversial
  • Systemic symptoms may occur due to hormonal secretion by the tumor:
    • Tumor secretion of calcitonin, calcitonin gene-related peptide, or other substance:
      • Can cause diarrhea or facial flushing in patients with advanced disease
    • In addition, occasional tumors secrete corticotropin (ACTH):
      • Causing ectopic Cushing’s syndrome
• Biochemical tests:
  • Basal serum calcitonin concentrations:
    • Usually correlate with tumor mass but also reflect tumor differentiation, and they are almost always high in patients with a palpable tumor
  • Most MTCs also secrete carcinoembryonic antigen (CEA):
    • Which, like calcitonin, can be used as a tumor marker
    • In addition, the expression of CEA on MTC cells has led to the use of anti-CEA antibodies for immunotherapy
  • Thyroid function tests are normal in patients with MTC
• Imaging:
  • There are several ultrasound features of thyroid nodules (eg, hypoechoic, microcalcifications) that are associated with thyroid cancer risk:
    • However, there are no ultrasound features that are pathognomonic for thyroid cancer.
    • Furthermore, the majority of studies evaluating suspicious ultrasound characteristics of nodules focused on papillary thyroid cancer
    • In a small retrospective study examining the ultrasound characteristic of nodules that were histologically proven to be MTC and papillary thyroid cancer
      • 50% of MTCs were solid and hypoechoic
      • 16% showed microcalcifications
        • Compared with 69.2% and 69.2%:
          • Respectively, for papillary thyroid cancers 
        • The presence of at least one suspicious ultrasound feature was almost equal in patients with MTC (58.3%) and controls with benign nodules (55.5%), whereas it was significantly more frequent in patients with papillary thyroid cancer (100%)
    • In other series
      • Hypoechogenicity was present in 50% to 89% and microcalcifications in 30% to 70%:
        • There was no difference in echogenicity or the presence or type of calcifications between MTC and papillary thyroid cancer .
      • Large areas of calcification (macrocalcification) were noted in 16% to 30%:
        • Rarely:
          • The diagnosis of MTC is suggested by the presence of dense calcifications seen on radiographs or imaging of the anterior neck.
• Inherited MTC:
  • Multiple endocrine neoplasia type 2 (MEN2):
    • Is subclassified into two distinct syndromes (MEN2A and MEN2B):
      • Each of which is transmitted in an autosomal dominant fashion and is associated with MTC
    • These syndromes result from:
      • Different mutations in the RET proto-oncogene
    • In the past:
      • Familial MTC (FMTC):
        • An inherited syndrome characterized by the presence of only MTC without hyperparathyroidism or pheochromocytoma:
          • Was considered a separate entity but is now considered a variant of MEN2A
  • Hereditary MTC is:
    • Typically bilateral and multicentric:
      • Classical MEN2A is associated with:
        • MTC
        • Pheochromocytoma
        • Primary parathyroid hyperplasia
          • While the penetrance of MTC is nearly 100%:
            • There is inter- and intrafamily variability in the specific pattern of the other disease manifestations
    • MEN2B shares the inherited predisposition to MTC and pheochromocytoma present in classical MEN2A:
      • But does not include hyperparathyroidism
      • MTC occurs in almost all patients
      • The tumor develops at:
        • An earlier age and may be more aggressive than in MEN2A
      • Patients typically have:
        • A marfanoid habitus (but do not have Marfan syndrome),
        • Mucosal neuromas
        • Intestinal ganglioneuromatosis
    • In the index case:
      • The clinical presentation and manifestations of MEN2-associated MTC are similar to those of sporadic MTC:
        • The most common presentation is that of:;
          • A solitary thyroid nodule or cervical lymphadenopathy
      • Early diagnosis (prior to any clinical manifestations) by screening of “at-risk” family members in MEN2 kindreds is important because MTC is a life-threatening disease that can be cured or prevented by early thyroidectomy

• What is Head and Neck Surgery?:
  • It is a surgical sub-specialty that deals mainly with benign and malignant tumors of the head and neck region, including:
    • The scalp, facial region, eyes, ears, nose, nasal fossae, paranasal sinuses, oral cavity, pharynx (nasopharynx, oropharynx, hypopharynx), larynx (supraglotic larynx, glottis larynx, subglotic larynx), thyroid gland, parathyroid gland, salivary glands (parotid glands, submandibular glands, sublingual glands, minor salivary glands), soft tissues of the neck, skin of the head and neck region.
      • The head and neck surgeon’s work area:
        • Does not cover tumors or diseases of the brain and other areas of the central nervous system or those of the cervical spine:
          • This is the neurosurgeon field.
  • Among the diagnostic procedures performed by the head and neck surgeon,  are the following:
    • Nasopharyngolaryngoscopy:
      • Performed to examine, evaluate and, possibly perform a biopsy, of oral cavity, pharyngeal and laryngeal lesions.
  • The surgeries most commonly performed by the head and neck surgeon are:
    • Total or near total thyroidectomies
    • Hemithryoidectomies (lobectomies)
    • Comprehensive neck dissections
    • Selective neck dissections
    • Maxillectomies:
      • Total maxillectomy
      • Subtotal maxillectomy
      • Infrastructure maxillectomy
      • Suprastructure maxillectomy
      • Medial maxillectomy
    • Mandibulectomy:
      • Segmental
      • Marginal
    • Tracheostomy
    • Salivary gland surgeries:
      • Parotid gland operations:
        • Limited superficial parotidectomy with identification and preservation of the facial nerve
        • Superficial parotidectomy with identification and preservation of the facial nerve
        • Near total parotidectomy with identification and preservation of the facial nerve
        • Total parotidectomy
      • Submandibular gland resection
      • Sublingual gland resection
    • Resection of tumors of the oral cavity:
      • Glossectomy
      • Resection of the floor of the mouth tumors
    • Resection of tumors of the pharynx
    • Resection of tumors of the larynx
    • Split-thickness skin grafts
    • Full-thickness skin grafts
    • Sentinel lymph node mapping and sentinel lymph node biopsy
    • Resection of malignant skin tumors (BCC, SCC, melanoma) of the head and neck region
• The formation of the head and neck surgeon includes mastering the following subjects:
  • Surgical Anatomy
  • History and Basic Principles of Head and Neck Surgery
  • Epidemiology, Etiology, and Pathology of Head and Neck Diseases
  • Diagnostic Radiology of the Head and Neck Region
  • Tumors of the Scalp, Skin and Melanoma
  • Eyelids and Orbit
  • Nasal Cavity and Paranasal Sinuses
  • Skull Base and Temporal Bone
  • Lips and Oral Cavity
  • Pharynx and Esophagus
  • Larynx and Trachea
  • Cervical Lymph Nodes
  • Thyroid and Parathyroid Glands
  • Salivary Glands
  • Neurogenic Tumors and Paragangliomas
  • Soft Tissue Tumors
  • Bone Tumors and Odontogenic Lesions
  • Reconstructive Surgery
  • Oncologic Dentistry and Maxillofacial Prosthetics
  • Principles of Radiation Oncology
  • Principles of Chemotherapy
  • Molecular Oncology, Genomics and Immunology
  • Nutrition
  • Biostatistic

 

• Rodrigo Arrangoiz MS, MD, FACS a head and neck surgeon / endocrine surgeon / surgical oncologist and is a member of Sociedad Quirúrgica S.C at the America British Cowdray Medical Center in Mexico City:

 

• Rodrigo Arrangoiz MS, MD, FACS:
  • Is a member of the American Head and Neck Society

• • He is a member of the American Thyroid Association:

Training:

• General surgery:

• Michigan State University:

• 2004 al 2010

• Surgical Oncology / Head and Neck Surgery / Endocrine Surgery:

• Fox Chase Cancer Center (Filadelfia):

• 2010 al 2012

• Masters in Science (Clinical research for health professionals):

• Drexel University (Filadelfia):

• 2010 al 2012

• Surgical Oncology / Head and Neck Surgery / Endocrine Surgery:

• IFHNOS / Memorial Sloan Kettering Cancer Center:

• 2014 al 2016

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