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ciliated muconodular papillary tumor

Monday 31 October 2016

Ciliated Muconodular Papillary Tumors of the Lung; CMPT

Ciliated muconodular papillary tumors (CMPTs) are rare peripheral lung lesions, characterized by papillary architecture and ciliated columnar cells admixed with mucinous cells and basal cells.

They often have prominent surrounding intra-alveolar mucin, which can lead to diagnostic confusion with mucinous adenocarcinoma.

Recognition of the ciliated component is the key to diagnosis of CMPT. The literature contains few reported cases to date, all occurring in East-Asian patients.

CMPT seems to be an indolent tumor with very good prognosis, leading some to question whether it is a reactive or hamartomatous lesion.

Molecular biology

A very recent molecular study has identified BRAF (40%) and EGFR (30%) alterations in CMPT, supporting a truly neoplastic process.

One case occurred in background of pronounced small airway disease with necrotizing bronchiolitis and multiple carcinoid tumorlets.

A study identified 2 pathogenic mutations (BRAF-V600E and AKT1-E17K). These data confirm BRAF V600E mutation as a probable driver in a subset of these tumors, along with AKT1 mutation, which further supports that CMPT are indolent pulmonary neoplasms.

Paywall references

- Ciliated Muconodular Papillary Tumors of the Lung Can Occur in Western Patients and Show Mutations in BRAF and AKT1. Liu L, Aesif SW, Kipp BR, Voss JS, Daniel S, Aubry MC, Boland JM. Am J Surg Pathol. 2016 Jul 22. PMID: 27454941