Primary Intestinal-Type Adenocarcinoma of Tongue: A Case Report with Immunohistochemical and Molecular Profiles and Review of the Literature

Abstract

Primary lingual intestinal-type adenocarcinomas are extremely rare with only a few cases described. A case with immunohistochemical expression of Androgen Receptor (AR) which was treated solely by chemo-radiotherapy is reported herein. A 54-year-old male was referred with symptoms of fullness in his tongue. Clinical examination showed an asymmetry of the tongue with a hard mass palpable within the middle of the tongue. Biopsy showed intestinal-type adenocarcinoma. The tumour showed positive staining with cytokeratin 7, cytokeratin 20, CDX2, AR, β-catenin and was mismatch repair proteins (MMR) proficient. The molecular analysis did not show mutations in the KRAS, NRAS, BRAF and PIK3CA genes. The patient was treated with radiochemotherapy and is in remission 3.5 years after the diagnosis. This is the first case of intestinal-type tongue adenocarcinoma which showed AR expression and was treated solely with radical chemoradiotherapy.

Keywords: Adenocarcinoma; Androgen receptor; Intestinal type; Salivary gland; Tongue.

Fig. 1

a and b MRI post-gadolinium axial T1 fat suppressed image showing enhancing lesion in the mid tongue. Pre-treatment PET–CT scan showing a metabolically active tumour in the mid tongue, Standardized Uptake Value (SUV) max 10

Fig. 2

Post-treatment PET–CT scan showing complete metabolic response to treatment

Fig. 3

a and b Moderately differentiated intestinal-type adenocarcinoma with glands and tubular structures. The glands are lined by cells with elongated nuclei. The arrow indicates nerve invasion (original magnification ×40; Haematoxylin and Eosin)

Fig. 4

Immunohistochemistry shows intense and diffuse positive cytoplasmic staining with CK 7 and nuclear staining with CDX2 and AR while CK 20 is patchy and moderate. Lesional cells manifest strong positive staining for β-catenin