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Mucinous micropapillary pattern in lung adenocarcinomas: a unique histology with genetic correlates
Author(s) -
Kamata Tsugumasa,
Yoshida Akihiko,
Shiraishi Kouya,
Furuta Koh,
Kosuge Tomoo,
Watanabe Shunichi,
Asamura Hisao,
Tsuta Koji
Publication year - 2016
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1111/his.12763
Subject(s) - histology , pathology , lung , adenocarcinoma , medicine , biology , cancer
Aims In lung adenocarcinoma ( ADC ), micropapillary carcinomas ( MPC s) are associated with poor prognosis because these tumours exhibit higher metastatic potential. Despite this, there are no studies investigating the differences between mucinous and non‐mucinous MPC . Methods and results We evaluated the proportion of micropapillary components in lung ADC s, and compared the differences with respect to the presence or absence of associated mucin. Tumour specimens from 694 patients with consecutively resected primary lung ADC were reviewed, and 37 cases of invasive mucinous ADC s were excluded. A significant (≥5%) micropapillary component was noted in 320 (48.7%) of 657 evaluable cases. When the cases with micropapillary component were divided into 67 (20.9%) mucinous and 253 (79.1%) non‐mucinous subtypes, tumours with mucinous micropapillary component exhibited significantly more aggressive pathological features, a higher proportion of HER 2 mutations ( P = 0.002) and ALK rearrangements ( P < 0.001), and a lower proportion of EGFR mutations ( P = 0.038) compared to those with a non‐mucinous micropapillary component. In survival analyses, mucinous MPC tended to be more aggressive compared with non‐mucinous MPC , but its prognostic value was not statistically significant ( P = 0.076). Conclusions Mucinous micropapillary pattern is an under‐recognized unique growth associated significantly with HER 2 mutation and ALK rearrangement.