Cytology of primary pulmonary mucoepidermoid and adenoid cystic carcinoma - A report of four cases

BACKGROUND: Mucoepidermoid and adenoid cystic carcinomas are very rare prim ary pulmonary neoplasms that can be classified under the broader heading of salivary gland-like neoplasms (SGN). Both entities need to be considered i n the cytologic differential diagnosis of lung tumors. We reviewed cytologi c findings in primary pulmonary neoplasms diagnosed at our institution duri ng the time period 1981 to the present along with outside consultation case s. CASES: Three cases of primary mucoepidermoid carcinoma and one case of prim ary adenoid cystic carcinoma of the lung were diagnosed based on cytology d uring the period examined. Patient ages were 16, 25, 47 and 78 years, respe ctively. The mucoepidermoid cytology specimens were composed of three cell types, mucinous, squamous and intermediate cells, at times associated with extracellular mucin. The adenoid cystic carcinoma consisted of small, unifo rm cells with dark nuclei, scant cytoplasm and associated, acellular balls of basement membrane material. CONCLUSION: The differential diagnosis for primary pulmonary neoplasms need s to include the rare SGN. Cytologic features of adenoid cystic carcinoma a re diagnostic; those of mucoepidermoid carcinoma are at least suggestive.