Bronchiolar Adenoma/Pulmonary Ciliated Muconodular Papillary Tumor
Hemlata Shirsat, Fang Zhou, Jason C. Chang, Natasha Rekhtman, Anjali Saqi, Kimon V. Argyropoulos, Lea Azour, Anthony Simms, Jonathan Melamed, Yin P. Hung, Anja C. Roden, Mari Mino–Kenudson, André L. Moreira, Navneet Narula
Abstract
OBJECTIVES: To describe the histologic features that are helpful in the diagnosis of the rare bronchiolar adenomas/ciliated muconodular papillary tumors (BAs/CMPTs) during intraoperative consultation. METHODS: Multi-institutional retrospective review of frozen sections of 18 BAs/CMPTs. RESULTS: In 14 of 18 cases, BA/CMPT was the primary reason for sublobar lung resection, and in 4 cases, BA/CMPT was an incidental finding intraoperatively for resections performed for carcinoma in other lobes. There were 11 proximal-type/classic BAs/CMPTs and 7 distal-type/nonclassic BAs/CMPTs. Only 3 (16.7%) of 18 were correctly diagnosed at the time of frozen section, all of which were proximal type/classic. The remainder were diagnosed as adenocarcinoma (n = 7); invasive mucinous adenocarcinoma (n = 1); non-small cell lung carcinoma (n = 1); cystic mucinous neoplasm, favor adenocarcinoma (either mucinous or colloid type) (n = 1); favor adenocarcinoma, cannot exclude CMPT (n = 1); atypical proliferation (n = 2); mucinous epithelial proliferation (n = 1); and mucous gland adenoma (n = 1). CONCLUSIONS: BA/CMPT can potentially be misdiagnosed as carcinoma during intraoperative consultation. On retrospective review of the frozen sections, the presence of the following may help to avoid misdiagnosis: a mixture of bland ciliated columnar cells, mucinous cells, and, most important, a basal cell layer, as well as a lack of necrosis, significant atypia, and mitoses.