Background: Fine needle aspiration (FNA) cytology can be used to diagnose a rare subtype of monomorphic adenoma, dermal analogue tumor.
Case: A 70-year-old male presented with a mass in the parotid gland. An FNA aspirate was obtained using multiple passes in the mass. Filter preparations from aspirated material were made and stained by the Papanicolaou method, while cell blocks from aspirate and excised tissue were stained by hematoxylin-eosin after processing. The cytohistologic features in the cellular sample were characterized by aggregates of uniform epithelial cells with regular nuclei; fine chromatin; a few, regular nucleoli; scanty, ill-defined cytoplasm; no nuclear pleomorphism or mitotic activity; and cell groups bordered by thick, basement membrane-like material.
Conclusion: Dermal analogue tumor of the salivary gland mimics dermal cylindroma and can recur. This was true in the case presented since the tumor recurred after 11 months. An analogy between adenomas of salivary glands and those of skin adnexa is not surprising since both arise in germinal epithelium of ectodermal origin. Also, the biologic behavior of these adenomas is similar, with a close histogenetic relationship. The findings suggest that the cytomorphologic expression of dermal analogue tumor is distinctive and that diagnosis of this neoplasm by FNA cytology is possible.