P3728 - PTEN Hamartoma Tumor Syndrome: A Rare Case in a Young Patient with Colorectal Cancer

Nutdanai Roila, MD, Chanitra Thuwajit, MD, PhD, Manop Pithukpakorn, MD, Varut Lohsiriwat, MD, Jomjit Chantharasamee, MD
Siriraj Hospital, Mahidol University, Bangkok, Krung Thep, Thailand

Introduction: Pathogenic germline variants (PGVs) in colorectal cancer have been associated with multiple hereditary cancer syndromes. One such syndrome is PTEN Hamartoma Tumor Syndrome (PHTS), which has the potential to cause early-onset malignancies in various organs, often manifesting as gastrointestinal neoplasia.

Case Description/Methods: A 38-year-old man with a known case of stage II sigmoid adenocarcinoma, status post-sigmoidectomy, and completed chemotherapy at another hospital, presented to our institution for ongoing follow-up care. Initial evaluations were within normal limits. Routine surveillance imaging of the chest and abdomen was performed. Surprisingly, the results revealed a few polypoid lesions in the gastric fundus and antrum, along with multiple thyroid nodules in both lobes. Upper and lower GI endoscopy was scheduled. Colonoscopy was performed first and demonstrated multiple polyps in the colon. During a subsequent Esophagogastroduodenoscopy (EGD), the patient unexpectedly desaturated to 70% oxygen. An anesthesiology emergency call was promptly activated, and difficult intubation was finally achieved on the third attempt by an attending anesthesiologist. The patient was admitted to the ICU. An otolaryngology consult was conducted and revealed numerous polypoid lesions in the soft palate, oropharynx, and base of the tongue. The EGD also showed multiple small polyps throughout the stomach and extending to the second part of the duodenum. Biopsies revealed multiple tubular adenomas in the stomach, duodenum, and colon. Polyposis syndrome was highly suspected. Genetic consultation was conducted, and next-generation sequencing (NGS) confirmed a pathogenic PTEN, indicating PTEN Hamartoma Tumor Syndrome. The patient recovered during hospitalization and was subsequently discharged.

Discussion: The young age of colorectal cancer onset and the presence of multiple abnormal polypoid lesions in various GI organs, along with multiple thyroid nodules, highlight the importance of genetic assessment, particularly for PGVs, in this patient. The increasing accessibility of germline testing such as NGS emphasizes the need for clinicians to consider identifying individuals at risk of carrying PGVs. Pathogenic PTEN has a wide variety forms of harmatoma polyposis syndrome. Breasts, Endometrium, kidneys, and skin should also be closely monitored as a significant increase risk in developing life time cancer in these organs.


Disclosures:


Nutdanai Roila, MD, Chanitra Thuwajit, MD, PhD, Manop Pithukpakorn, MD, Varut Lohsiriwat, MD, Jomjit Chantharasamee, MD. P3728 - PTEN Hamartoma Tumor Syndrome: A Rare Case in a Young Patient with Colorectal Cancer, ACG 2024 Annual Scientific Meeting Abstracts. Philadelphia, PA: American College of Gastroenterology.