Overview
Eccrine porocarcinoma is a rare malignant adnexal tumor originating from eccrine sweat gland acrosyringia, predominantly affecting elderly individuals with a high risk of metastasis 1.Diagnosis
Clinical Presentation: Often presents as a firm, ulcerative mass, commonly in the elderly 13.
Histopathology: Characterized by malignant transformation of eccrine sweat gland structures 1.
Differential Diagnosis: Challenging differentiation from squamous cell carcinoma; useful markers include NUT expression and YAP1 fusion products 1.
Immunohistochemistry: Androgen receptor (AR) expression noted in about 25% of cases, typically focal/weak, more common in males 2.Management
Primary Treatment: Wide local excision is the mainstay; Mohs micrographic surgery shows promise 1.
Lymph Node Management: Role of sentinel lymph node biopsy and subsequent dissection remains controversial 1.
Radiotherapy: Applied based on tumor characteristics and excision margins; specifics not universally standardized 13.
Systemic Therapy: Limited data; pembrolizumab and EGFR inhibitors show potential in advanced cases 1.Special Populations
Elderly: Predominantly affects elderly patients, with considerations for surgical complexity and adjuvant therapies 13.
Unusual Locations: Cases in atypical sites like the vulva or ear require vigilant monitoring for metastasis and recurrence 34.Key Recommendations
Surgical Excision: Wide local excision is recommended for primary treatment of eccrine porocarcinoma (Evidence: Strong 1).
Consideration of Mohs Surgery: Mohs micrographic surgery may be considered for optimal local control (Evidence: Moderate 1).
Adjuvant Radiotherapy: Use based on tumor margins and characteristics, lacking standardized guidelines (Evidence: Weak 13).
Sentinel Lymph Node Biopsy: Role remains undefined; decision should be individualized (Evidence: Expert opinion 1).
Advanced Disease: Evaluate systemic therapies like pembrolizumab and EGFR inhibitors in consultation with oncologists (Evidence: Weak 1).References
1 Bienstman T, Güvenç C, Garmyn M. Porocarcinoma: Clinical and Histological Features, Immunohistochemistry and Outcomes: A Systematic Review. International journal of molecular sciences 2024. link
2 Fernandez-Flores A, Cassarino DS. Immunoexpression of Androgen Receptors in Poroid Neoplasms. Applied immunohistochemistry & molecular morphology : AIMM 2017. link
3 Fujimine-Sato A, Toyoshima M, Shigeta S, Toki A, Kuno T, Sato I et al.. Eccrine porocarcinoma of the vulva: a case report and review of the literature. Journal of medical case reports 2016. link
4 Thompson L, Malone J, Schadt C. Erythematous nodule of the ear. Dermatology online journal 2014. link