1474 Cowden and MAP Syndrome: The Untold Story of a Screening Colonoscopy—Case Report

Abstract

INTRODUCTION: Cowden syndrome is a rare autosomal dominant condition associated with PTEN gene mutation. MUTYH-associated polyposis (MAP) is inherited by autosomal recessive fashion. Cowden syndrome presents with multiple hamartomas in a variety of tissues, oral fibromas, and punctate palmoplantar keratoses, and an increased risk of breast, endometrial, thyroid, kidney and colorectal cancers. MAP syndrome is associated with adenomatous polyps and colon cancer predisposition. CASE DESCRIPTION/METHODS: 51-year-old female underwent screening colonoscopy and was found to have multiple polyps throughout the colon. Biopsy showed ganglioneuromas and hamartomous polyps. Medical history was significant for hypothyroidism and hypoparathyroidism secondary to thyroidectomy for a goiter, bilateral mastectomy for a ductal carcinoma in situ, hysterectomy for fibroids, palmar keratosis and oral papillomatosis. Family history was relevant for breast cancer in her mother at age 50. Genetic analysis revealed mosaicism for a loss of function variant in PTEN and autosomal recessive pathogenic single MUTYH variant which confirmed Cowden Syndrome and carrier state for MAP syndrome. Appropriate cancer surveillance was arranged for our patient according to the National Cancer Center Network Guidelines through multidisciplinary approach. DISCUSSION: PTEN gene is a tumor suppressor responsible for regulating the cell cycle. Because of her mutation, our patient is susceptible for an array of different malignancies. Her genetic profile showed mosaicism for PTEN genetic variant. Adequate cancer surveillance for colon cancer, renal cell carcinoma and recurrence of breast cancer were discussed with our patient. MUTYH variant mutation was found in this patient. However, she inherited only one single copy of this recessive gene expecting not to develop clinical MAP syndrome. Risks associated with a single variant in MUTYH are unclear. There are some reports that suggest an inconsistent increased risk of colon, endometrial, and breast cancer. National Cancer Center Network Guidelines has created surveillance guidelines for individuals with a single MUTYH variant but cautioned that these guidelines are likely to change over time. Uniquely, extracolonic neoplastic complications were detected before the diagnosis of Cowden in our patient. High clinical suspicion and early diagnosis of this condition is crucial for effective prevention of colonic and extracolonic malignancies that these individuals are at high risk for.