BACKGROUND: Primary mucinous carcinoma of the skin is a rare sweat gland neoplasm which occurs most commonly in the periorbital region. Although the tumor has a propensity for local recurrence and regional spread, distant metastases are rare. The standard treatment of primary mucinous carcinoma is wide local excision. Mohs micrographic surgery may also be utilized in cases where tissue conservation is of utmost concern. OBJECTIVE: We present a case of primary mucinous carcinoma arising in the scalp, which was treated with wide local excision. METHODS: A case report and literature review are presented. RESULTS: Histopathologic evaluation revealed a well-circumscribed neoplasm characterized by lobules and aggregates of epithelial cells embedded in abundant pools of mucin. In addition, small aggregates of neoplastic cells were found at a distance from the primary nodule, indicative of lymphatic invasion. CONCLUSION: Primary mucinous carcinoma has a high propensity for locoregional metastases and recurrence. To our knowledge, this is the first report demonstrating direct histopathologic evidence of lymphatic invasion which correlates with this tumor's biologic behavior.

Primary cutaneous mucinous carcinoma: report of two cases treated with Mohs' micrographic surgery.Australas J Dermatol. 2006 Aug;47(3):192-4.

We present a 72-year-old woman who presented with a slowly enlarging, asymptomatic, cystic nodule on the right eyebrow, and a 66-year-old woman who had a reddish, nodular lesion on the left lower eyelid. Incisional biopsy from the two neoplasms showed dermal epithelial cell islands embedded in mucin pools. Tumour cells stained positive for cytokeratin 7, oestrogen and progesterone receptors, and negative for vimentin and S-100 protein. These findings were consistent with a diagnosis of mucinous carcinoma. Extensive work-ups excluded cutaneous metastases from primary visceral mucinous carcinomas. To ensure complete tumour removal, both patients underwent Mohs' micrographic surgery (standard fresh-frozen technique). They remain disease-free 42 and 26 months after surgical excision, respectively. Mohs' micrographic surgery appears to be a rational and effective treatment for this uncommon malignancy.