Diffuse Esophageal Glycogenic Acanthosis: Not Always Incidental

A 39-year-old man presented for workup of bloating. He had no relevant medical history. Colonoscopy showed a circumferential tumor in the transverse colon with biopsy specimens confirming adenocarcinoma (Figure A). Esophagogastroduodenoscopy showed diffuse glycogenic acanthosis (GA) throughout the esophagus, verified as glycogen-rich by iodine staining (Figure B). The patient was noted to have macrocephaly, mucocutaneous trichilemmomas (Figure C), and oral papillomas (Figure D). Macrocephaly and macroscopic manifestations met the major criteria of Cowden syndrome (CS), whereas colon cancer development and GA met the minor criteria. He underwent transverse colectomy with lymph node dissection. Despite adjuvant and salvage chemotherapy, he died after 16 months from peritoneal dissemination. Germline pathogenic variants of the PTEN gene cause phosphatase and tensine homolog hamartoma tumor syndrome (PHTS), including CS, Bannayan–Riley–Ruvalcaba syndrome, and phosphatase and tensine homolog-related Proteus syndrome. More than 80% of CS cases inherit PTEN mutations. The patient was diagnosed with CS based on germline PTEN mutation (CGA (arginine)→TGA (stop codon) at codon 130, exon 5. CS patients have a 30% lifetime malignancy risk. The patient had not been diagnosed with CS before because he had never undergone any medical check-up. GA is considered an incidental finding in most clinical settings; however, it should be noted that it also can be a PHTS-related gastrointestinal manifestation. In the appropriate context, the association of diffuse GA with PHTS should be kept in mind for early diagnosis and management. The authors would like to thank Editage (www.editage.com) for English language editing.