Primary adenoid cystic carcinoma in the peripheral lung: a cytological, histopathological and immunohistochemical report of two cases

Fumimasa Etori,Toshiyuki Sawa,Takuji Tanaka,Masashi Matsuyama,Naoki Watanabe,Takafumi Naiki,Tsutomu Marui,Naomi Kawaguchi,Kyoko Nambu,Toshimasa Sakakima,Asuka Sekiya

doi:10.7243/2052-7896-3-3

Abstract

Primary adenoid cystic carcinoma (ACC) of the peripheral lung is a rare entity. Here we report two cases of primary ACC. Case 1 is an 84-year-old male with a past-medical history of cecal cancer presented with a 10 mm left upper lung nodule. Case 2 is a 40-year-old female who presented with 30 mm right upper lobe. Intraoperative (Case 1) and pre-operative (Case 2) histopathologic and cytologic diagnoses were consistent with a primary peripheral lung ACC. An upper lobectomy±mediastinal lymph node dissection was performed and immunohistochemical staining with thyroid transcription factor (TTF)-1, c-KIT and MYB on the excision specimen confirmed our diagnosis.

Highlights

Adenoid cystic carcinoma (ACC) is a biphasic tumor consisting of epithelial and myoepithelial cells
Primary lung ACC is categorized as a salivary-type lung cancer which mostly occurs in the trachea, carina, or in a main stem bronchus (70.7%) [3]
Primary pulmonary ACC most often develops in the lower trachea or mainstem bronchus [6] and accounts for approximately 0.2% of all cases of primary lung cancer [7]

Summary

Introduction

Adenoid cystic carcinoma (ACC) is a biphasic tumor consisting of epithelial and myoepithelial cells. Case 2 A 40-year-old Japanese woman was referred to our hospital for evaluation of a right upper lobe lung mass, which had been found incidentally on chest X-ray examination for symptoms of an acute upper respiratory infection She did not present with any symptoms related to bronchial obstruction and had no previous medical problems. Case 2 Examination of the right upper lobectomy specimen showed a 30x24x22 mm well-circumscribed, lobulated, white mass (Figure 8) in the periphery of the lung without any connection to the bronchial tree or submucosal extension. The tumor consisted of two cell types, epithelial and myoepithelioid cells, with predominantly the latter cells (Figures 3a and 3b) They were relatively small and uniform with round or ovoid nuclei. Cytological findings Case 1 The touch imprint slides showed tumor cells in ball-like (Figure 4b). Case 2 Papanicolaou-stained FNAC smears were moderately cellular, and consisted mostly of tightly cohesive aggregates of relatively small, uniform tumor cells (Figures 6a-6d). Case 1 had a MIB-1 (Figures 9m and 9n) index of 60% and Case 2 had a MIB-1 index of 40%

Discussion

Findings

Conclusion