Mucosal Microcystic Adnexal Carcinomas of the Head and Neck: A Report of 4 Cases
Anne M Mills, Maria L Policarpio-Nicolas, Stacey E Mills. University of Virginia, Charlottesville, VA; University of Texas Health Science Center at San Antonio, San Antonio, TX
Background: Microcystic adnexal carcinoma (MAC) is a rare neoplasm occurring predominantly in the centrofacial skin of middle-aged patients. MACs demonstrate a stereotypic morphology with minimally atypical cells arranged in angulated ducts percolating through densely sclerotic stroma. Despite their bland appearance, these tumors show extensive invasion, local destruction, and are prone to recurrence. Their identification is frequently straightforward in the facial skin, but they pose significant diagnostic difficulties when they arise in alternate locations. On our consultation service, we have encountered several diagnostically challenging cases of MAC occurring in the head and neck. To our knowledge, there has only been a single report (Schipper et al, 1995) of this tumor occurring in the tongue and one report from the parotid gland (Hunt et al 1995). We know of no prior reports of MAC arising in the nasopharyngeal area or clivus.
Design: The University of Virginia Department of Pathology internal and consultative files were searched for all cases of MAC arising in the head and neck between 12/2003 and 9/2012.
Results: Four consultation cases were identified (Table 1). Each case demonstrated infiltrating cords, islands, and tubules comprised of minimally atypical cuboidal cells with round to oval nuclei and fine chromatin. Nucleoli were rarely prominent and mitotic figures were infrequent. Desmoplastic stroma was consistently evident in the background. Perineural invasion was identified in two cases, and three cases showed invasion of the skeletal muscle. One case closely abutted a minor salivary gland.
|Case #||Patient Age||Patient Sex||Tumor Location||Presentation|
|1||41||F||Base of tongue||Tongue mass|
|2||47||F||Anterior tongue||Tongue lesion|
|3||73||M||Nasopharynx, clivus||Diplopia for 8 months|
|4||54||F||Floor of mouth||Floor of mouth lesion|