Malignant Ciliated Muconodular Papillary Tumors of the Lung: A Case Report

Abstract

Ciliated muconodular papillary tumors (CMPTs) are rare peripheral lung lesions, characterized by papillary architecture and ciliated columnar cells admixed with mucous cells and basal cells. Only about 50 cases have been reported to date and is categorized as a benign neoplasm. In this article, we report an extremely rare case of 79-year-old man with a CMPT that developed in his right upper lobe. The central region of the tumor showed features of classic CMPT, while marginal area of the tumor showed the characteristics of invasive lung cancer. In central classic CMPT region, the ciliated, basal, and mucous cells were positive for thyroid transcription factor-1, cytokeratin 7 (CK7), and NapsinA. Basal cells were positive for CK5/6 and p40. Mucous cells were weakly positive for MUC2 and MUC5AC. However, CK5/6 and p40 were negative in the peripheral malignant area. Both of the benign and malignant regions had an EGFR driver mutation in exon 21. We concluded that this tumor was an extremely rare malignant case of CMPT.

Malignant transformation of pulmonary bronchiolar adenoma into mucinous adenocarcinoma: A case report

“…Four previous publications reported patients who had BA/CMPT with malignant transformation (Table 1 )[ 2 - 5 ]. Miyai and collaborators[ 2 ] presented a case of CMPT with malignant transformation of basal cells.…”

“…Han and co-workers[ 4 ] presented a unique case with loss of the continuous basal cell layer at the junction between BA and IMA, although the BA and IMA had the same KRAS mutations. Wang et al [ 5 ] also described a patient with malignant CMPT. We used H&E staining and immunohistochemistry to diagnose our patient as having MA caused by the malignant transformation of BA, thus providing histological evidence of the malignant potential of BA.…”

“…The limited knowledge of BA/CMPT and its morphologic similarity to malignant tumors, including invasive mucinous adenocarcinoma (IMA), presents a diagnostic challenge, especially in intraoperative frozen sections. We reviewed the available English language literature from 2002 to 2022 and identified only four cases of BA/CMPT with malignant transformation[ 2 - 5 ]. Thus, much the biological nature and clinical significance of BA/CMPT remain unknown.…”

Multiple Bronchiolar Adenomas With Malignant Transformation and CCNE1 Mutation: a Case Report and Literature Review

“…However, it is still controversial whether BA has malignant potential. More and more cases with malignant transformation have been reported in the literature recently (3)(4)(5)7). Miyai et al(3) reported a case of CMPT with malignant transformation of basal tumor cell components, and Chen et al (7) descripted a case of mucinous adenocarcinoma caused by cancerization from CMPT and speculated CMPT is a precancerous lesion of mucinous adenocarcinoma.…”

“…According to the proposal by Chang et al (1), the uni ed histological characteristic of BA is bilayered bronchiolar-type proliferation with a continuous layer of basal cells, which is considered to be the basis for BA identi ed as a benign tumor histologically. However, because of its rarity and potential malignant changes reported recently in few cases (2)(3)(4)(5), the biological potential of BA remains controversial and unclear. Herein, we report a rare case of multiple BAs with malignant transformation and CCNE1(cyclin E1)mutation, to increase the understanding of this disease and reduce missed diagnosis.…”