DOME/GALT type adenocarcimoma of the colon: a case report, literature review and a unified phenotypic categorization

Abstract

Several types of colorectal cancers are associated with a prominent lymphoid component, which is considered a positive prognostic factor. We report a case of a dome-type carcinoma of the cecum in a 57 year old female. The sessile, non-polypoid lesion histologically consisted of a tubulovillous adenoma with low-grade dysplasia. The submucosal invasive component showed low-grade architectural features that included cystically dilated glands containing eosinohilic debris. Immunohistochemical studies displayed retention of the four mistmach repair proteins, consistent with a stable phenotype. After 3 years, the patient remains free of recurrence. A literature review highlighted striking similarities between dome-type carcinoma and the gut-associated lymphoid tissue carcinoma, the two sharing an intimate association with the gut associated lymphoid tissue.The two variants might therefore be grouped into a unified category.

Fig. 1

Colonoscopic image of the caecal mass with a villous aspect

Fig. 2

Panoramic view of the polyp (H&E; ×1). The area in the box is shown at higher-power magnification in Fig. 3

Fig. 3

The submucosal invasive component in association with GALT (H&E; ×10)

Fig. 4

Adenocarcinoma with low-grade architectural features including cystically dilated glands with eosinohilic debris. Tumor cell cytoplasmic eosinophilia is also evident (H&E; ×50)