Eccrine Carcinoma

Eccrine carcinoma is an extremely rare neoplasm of the skin:
- That accounts for approximately 0.005% of malignant epithelial neoplasia
It arises from the eccrine sweat glands:
- There are least 10 described subtypes
Due to the rarity of these neoplasms:
- Exact etiology and clinical recommendations are not clear
Most of these tumors are:
- Slow-growing, solitary, dermal nodules:
  - That often arise from pre-existing benign skin lesions
Most common distribution is seen in:
- The head, neck, and extremities
The diagnosis is often delayed:
- Because of its relative rarity as well as difficulty in identification with traditional light microscopy
Recurrence is common
A wide local excision is the recommended treatment of choice:
- With a 70% to 80% cure rate
Mohs microsurgery:
- Can be used on cosmetically sensitive areas
Predictive factors for recurrence include:
- Tumors thicker than 7 mm
- Lymphovascular invasion
- Greater than 14 mitoses per high power field
- Dermal infiltration
Performing SLN biopsy on these patients is controversial:
- Lymph node metastasis is relatively rare and sentinel lymph node biopsy:
  - Is not routinely performed for all cases
Distant metastases are rare and cross-sectional imaging for staging work-up should be performed only when clinically indicated
Recurrent tumors:
- Are high risk for locoregional failure:
  - Should be considered for a sentinel lymph node biopsy
Distant metastasis is rare and any additional staging scans are not recommended
Radiation and chemotherapy have not demonstrated any significant benefit in the adjuvant setting
References
- Barnes M, Hestley A, Murray DR, Carlson GW, Parker D, Delman KA. The risk of lymph node involvement in malignant cutaneous adnexal tumors. Am Surg. 2014;80:270-274.
- Kampshoff JL, Cogbill TH. Unusual skin tumors: Merkel cell carcinoma, eccrine carcinoma, glomus tumors, and dermatofibrosarcoma protuberans. Surg Clin North Am. 2009;89:727-738.
- Luz Mde A, Ogata DC, Montenegro MF, Biasi LJ, Ribeiro LC. Eccrine porocarcinoma (malignant eccrine poroma): A series of eight challenging cases. Clinics (Sao Paulo). 2010;65:739-742.
- Wick MR, Goellner JR, Wolfe JT III, Su WP. Adnexal carcinomas of the skin, II: extraocular sebaceous carcinomas. Cancer. 1985;56:1163-1172.