Squamoid eccrine ductal carcinoma

Abstract Squamoid eccrine ductal carcinoma is an eccrine carcinoma subtype, and only twelve cases have been reported until now. It is a rare tumor and its histopathological diagnosis is difficult. Almost half of patients are misdiagnosed as squamous cell carcinoma by the incisional biopsy. We report the thirteenth case of squamoid eccrine ductal carcinoma. Female patient, 72 years old, in the last 6 months presenting erythematous, keratotic and ulcerated papules on the nose. The incisional biopsy diagnosed squamoid eccrine ductal carcinoma. After excision, histopathology revealed positive margins. A wideningmargins surgery and grafting were performed, which again resulted in positive margins. The patient was then referred for radiotherapy. After 25 sessions, the injury reappeared. After another surgery, although the intraoperative biopsy showed free surgical margins, the product of resection revealed persistent lesion. Distinction between squamoid eccrine ductal carcinoma and squamous cell carcinoma is important because of the more aggressive nature of the first, which requires wider margins surgery to avoid recurrence.

Clinical and histopathological analysis of 13 cases of tricholemmal carcinoma / 中华皮肤科杂志

Objective To investigate the clinical and histological characteristics of trichilemmal carcinoma (TLC). Methods A clinicopathological analysis of 13 cases of TLC was carried out. Results There were 9 males and 4 females among the 13 patients with TLC who were aged from 34 to 87 years (mean: 70 years). Clinically, the tumor presented as an exophytic mass; histologically, it was characterized by the proliferation of epithelial cells and keratinization of outer root sheath. Cytologically atypical clear cells predominated in the tumor tissue. Microscopy revealed different growth patterns of tumor cells, which included solid growth pattern, tobular pattern and trabecular pattern. Periodic acid Schiff (PAS) stain demonstrated clear cells in all the tumor tissues from the 13 patients. Immunohistochemistry was performed in tissue samples from 6 patients, and showed that these samples were positive to high molecular weight cytokeratin (CK-HMW) and epithelial membrane antigen (EMA), but negative to carcinomebrynic antigen (CEA), S-100, cytokeratin 8 (CK8)and epithelial antigen(Ber-Ep4). Follow-up over 4 months to 5 years revealed neither recurrence nor metastasis in 9 cases.Conclusions TLC is a low-grade malignancy of skin adnexal tumor without distinctive clinical features, and should be differentiated from other malignant clear cell tumors of the skin.