Primary mucinous eccrine carcinoma of the buccal space: A case report and review of the literature.

IMPORTANCE: Mucinous eccrine carcinoma is a rare entity that most commonly affects the head and neck. Due to its low frequency of occurrence, review of its etiology, histopathology, and treatment strategies is beneficial to all clinicians who may encounter similar appearing masses. OBSERVATION: An 84-year-old male presented with a blue mass on the left cheek. This mass started as a small bump and grew significantly over one year. His primary care physician monitored its growth and ultimately referred to an otolaryngologist. Imaging findings revealed a multi-lobular solid and cystic left buccal lesion. FNA was suggestive of low grade mucoepidermoid carcinoma. INTERVENTION: Patient underwent surgical excision with primary closure of the defect. Frozen section was consistent with low grade salivary malignancy. Final pathology revealed primary mucinous eccrine carcinoma of the skin. CONCLUSIONS AND RELEVANCE: Mucinous eccrine carcinoma is a rare entity commonly seen in the head and neck region. Mucinous deposits to the skin from primaries elsewhere in the body are much more common than primary lesions of the skin. Histology is a key component of the diagnosis but full oncologic workup is required. Treatment typically includes wide local excision with possible adjuvant chemotherapy or radiation for high risk features.