Primary Mucinous Carcinoma of the Skin: Review of Literatures with A Report of A Rare Case

Mucinous carcinomas of the skin are divided to primary and metastatic types. Metastatic mucinous carcinoma is more common than primary one. It originates from breast, upper airway, gastrointestinal tract, salivary and lacrimal glands, paranasal sinuses and urinary tract.Primary mucinous carcinoma of the skin (PMCS) is a rare low grade malignant neoplasm.Case:A 58-year-old man referred with a chief complaint of gradual left facial enlargement since eight months ago. Diabetes mellitus and hypertension were reported in the patient’s medical history. Clinical examination of the patient revealed a 4ïƒ5 cm mobile slightly firm dome shaped bulge caused facial asymmetry. No lesion was observed in buccal mucosa intraorally.Preoperative examination showed no involved lymph node or local and distant metastasis. Computed tumographic scan with contrast demonstrated a well defined hypoattenuated mass extending to the cortical margin of the mandible with no evidence of periostal reaction and cortical destruction. Based on clinical and radiographic findings, a primary diagnosis of fibroma was made. A 1ïƒ2 cm wedge shaped incisional biopsy was performed.Gross examination of the specimen represented a well circumscribed grayish blue soft gelatin like mass.Histopatologic examination displayed well differentiated small basophilic tumor cell foci floating in lakes of slightly staining amorphous extracellular mucin surrounded by connective tissues without invasion to deep structures consistent with the diagnosis of mucinous carcinoma.Specific and immunohistochemical staining represented tumoral cells were positive for PAS, mucicarmin and CK7. Comprehensive clinical and radiographic examination (CT, PET, chest, abdominal and pelvis radiography) were performed to rull out the possibility of metastatic mucinous carcinoma and all confirmed the diagnosis of primary one.Total excision with 1 cm safe margins was performed for the lesion. Long term follow up was recommended for the patient.Conclusion:PMCS is a rare tumor with indolent course and high recurrence. This tumor has a relatively good prognosis. Prior to diagnosis of PMCS, careful clinical, imaging and histophathologic examinations should exclude the possibility of a metastatic mucinous carcinoma. The treatment for PMCS is excisional surgery with clear margins and precise follow up.

کلیدواژه ها:

mucinous carcinoma ، primary mucinous carcinoma ، skin ، metastasis