Sebaceous carcinoma of the back: a case report and literature review

Extra ocular sebaceous carcinoma is a very rare, aggressive, malignant tumor arising in the adnexal epithelium of sebaceous gland that account for only about 25% of all sebaceous carcinomas (Wick et al. in Cancer 56(5):1163-72, 1985). The diagnosis of this tumor is difficult because its clinical appearance is atypical. The common treatment consists in wide local excision of the lesion with removal of local lymph node. We report the second case of sebaceous carcinoma involving the back. It was treated with surgical excision and sentinel lymph node biopsy.

A 69 year-old Caucasian woman presented with an erythematous, violaceus and exophytic lesion with central ulceration and leakage of purulent material in dorsal region at the level of T10-T11, measuring 7 × 6 cm in size. A biopsy of the lesion reported a moderately differentiated sebaceous carcinoma with lymph, vascular and perineural invasion. Extension studies revealed axillary lymphadenopathy and a renal lesion suggestive of angiomyolipoma based on tomographic findings. A biopsy of the axillary lymphadenopathy was performed, which was negative for malignancy. A wide excision of the lesion with a 2 cm margin and sentinel lymph node biopsy were performed. On histopathological examination was confirm the diagnosis of sebaceous carcinoma of the back. The patient had a good clinical course, and it was decided to follow up clinically every 6 months.

Sebaceous carcinoma can occur in locations other than the ocular region. It is frequently difficult to diagnose and has an unpredictable prognosis. The back is a particularly unusual site for this lesion. Surgery remains the mainstay of treatment, and a sentinel lymph node biopsy can be performed instead of removing all regional lymph nodes.