Recurrent Cutaneous Adenoid Cystic Carcinoma of Forehead

Abstract

Adenoid Cystic Carcinoma (ACC) is a malignant tumour more commonly seen in salivary glands and rarely arises from the skin as adnexal tumour. Cutaneous ACC is a rare malignant adnexal tumour of eccrine origin. It has an indolent course and rarely metastasizes. Hereby, authors report a case of 48-year-old male with complaints of swelling on right forehead present for the past four years. Clinical diagnosis of infected sebaceous cyst was made and excised with simple excision. The swelling reappeared within 15 days of first surgery. The cytological examination of the swelling revealed abundant cellularity with predominantly cohesive clusters of monomorphic population of cells centered around eosinophilic hyaline globules suggestive of ACC. Retrieval of previous biopsy report revealed diagnosis of ACC reaching the margins of excision, the report of which was neither collected by either operating surgeon nor by the patient. Histopathological examination revealed classical cribriform pattern of arrangement of tumour cells with perineural infiltration by tumour cells. Immunohistochemistry further confirmed the diagnosis. The present case report brings out the importance of clearance of surgical margins in malignant tumours, including skin adnexal tumours. It also highlights the importance of histopathological examination of benign looking skin adnexal tumours.