Primary colonic-type adenocarcinoma of the base of the tongue: a previously unreported phenotype

Abstract

Primary lingual adenocarcinomas are rare and typically of salivary or seromucinous glands origin. Similarly, metastatic adenocarcinoma from distant primary sites to the tongue is an uncommon event, with only 3 cases from a colonic primary site reported. We present, for the first time, 2 primary colonic-type adenocarcinomas of the base of the tongue and discuss their putative origin and the clinicopathologic characteristics.

Fig. 1

CT of the neck with IV contrast showing an enhancing tongue mass (case #1).

Fig. 2

The 4.5 cm firm tumor with ill-defined infiltrative boundaries was located in the submucosa (carcinoma #2).

Figs 3–4

The carcinomas in both patients were a well to moderately differentiated colonic-type adenocarcinoma, with characteristic columnar malignant epithelial cells forming tubular and glandular structures, and with intra-glandular necrosis (Figs. 3, 4). The carcinomas of patient #2 exhibited considerable mucinous component (Fig. 4). Both carcinomas manifested strong positive staining for CK20 and CDX2 (Figs 3, 4). No CK7 staining was noted in carcinoma #2 (Fig 4) but in carcinoma #1 a focal staining was noted in tumor cells (Fig. 3).

Figs 3–4

The carcinomas in both patients were a well to moderately differentiated colonic-type adenocarcinoma, with characteristic columnar malignant epithelial cells forming tubular and glandular structures, and with intra-glandular necrosis (Figs. 3, 4). The carcinomas of patient #2 exhibited considerable mucinous component (Fig. 4). Both carcinomas manifested strong positive staining for CK20 and CDX2 (Figs 3, 4). No CK7 staining was noted in carcinoma #2 (Fig 4) but in carcinoma #1 a focal staining was noted in tumor cells (Fig. 3).