Malignant transformation of bronchiole adenoma into invasive mucinous adenocarcinoma: a case report and literature review

Abstract

Background: Bronchiolar adenoma (BA)/ciliated muconodular papillary tumors (CMPTs) was previously considered to be a benign neoplasm, with the possibility of malignant transformation reported in a few cases. Thus, the exact nature and biological potential of BA/CMPT have not been fully elucidated. We here report a case of mucinous adenocarcinoma (MA) caused by malignant transformation of BA. Case presentation: A 57-year-old woman presented with a 17.0×7.0 mm nodule in the lower lobe of the left lung. Hematoxylin-eosin (H&E) staining and immunohistochemistry were performed. The tumor was composed of two areas: BA area and MA area. In BA area, the tumor was consisted by a bilayered structure of luminal cells and basal cells. Basal cells were positive for CK5/6, p63, and p40, while they were not detected in MA area. The Ki-67 proliferation index was low (1%~2%). Finally, the patient was diagnosed with BA accompanied by MA, and had a favourable outcome.Conclusions: BA is generally considered to be a benign tumor. The present study indicated that BA may be carcinogenic and we should be vigilant for its potentiality of malignant transformation in clinical practice.

DICER1 syndrome: clinical variety endocrine manifestations and features of diagnostics

“…Также у 1 пациента был выявлен многоузловой зоб, а другой наблюдался по поводу папиллярной карциномы щитовидной железы [35]. В 2013 г. описан единственный случай трансформации хондромезенхимальной назальной гамартомы в злокачественную форму [36]. Методом терапии является проведение полной хирургической резекции образования с целью предупреждения возможного рецидива.…”