Benign Mixed Tumour of Eccrine Origin Presenting as Upper Lip Swelling: A Report of a Rare Case and Literature Review.

Benign mixed tumors of eccrine origin are rare cutaneous neoplasms characterized by both epithelial and mesenchymal differentiation. These tumors, arising from eccrine sweat glands, often present as slow-growing, solitary nodules and are commonly misdiagnosed due to their nonspecific clinical appearance. We report the case of a 47-year-old male patient with a seven-month history of a firm, ill-defined upper lip swelling initially suspected to be a sebaceous cyst. Surgical excision followed by histopathological evaluation revealed features consistent with a benign mixed tumor of eccrine origin, showing prominent myoepithelial components, ductal structures, and chondromyxoid stroma. Mixed adnexal tumors of eccrine origin, including eccrine spiradenomas and chondroid syringomas, are rare but important differentials for mucocutaneous swellings. Histopathology remains the gold standard for diagnosis. Surgical excision offers an excellent prognosis, with low recurrence rates. This case underscores the importance of considering rare adnexal tumors in the differential diagnosis of lip swellings. Early recognition, complete surgical excision, and histological assessment are pivotal in achieving favorable outcomes.