Metachronous Adenoid Cystic Carcinoma in the Peripheral Lung and at Base of the Tongue

Abstract

Primary lung adenoid cystic carcinoma (ACC) is extremely rare and accounts for approximately 0.1%-0.2% of all lung cancers. ACC of the head and neck has generally been regarded as a slow-growing, low-grade malignancy which has a tendency for local recurrence and frequent distant metastasis. When ACC of the lung is identified, physicians must determine whether it represents distant metastasis or a primary lung cancer. Thyroid transcription factor-1 staining is one of the most useful methods to differentiate primary from metastatic lesions in lung cancer. Herein we report a case of metachronous, not synchronous, ACC at the peripheral lung followed by ACC presentation at the base of the tongue, and review of relevant literatures.

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

“…Our cases were positive for MYB and c-KIT, consistent with ACC. Tumor cells were also positive for TTF-1, indicating that the origin was the lung [1,22,23]. In Case 1, the patient had a history of adenocarcinoma of the colon posing an additional diagnostic challenge.…”

“…The lung ACC cells in the present study expressed TTF-1. TTF-1 is a protein expressesd in the forebrain, thyroid, and lung [24] and only a few reports [1,22,23] have described the expression of TTF-1 in primary lung ACC.…”

“…ACC also develops in several sites other than the salivary gland. Primary lung ACC is extremely rare and accounts for approximately 0.04%-0.2% of all lung cancers [1,2]. 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].…”