Peutz-Jeghers Syndrome: From Intestinal Polyposis and Mucocutaneous Pigmentation to Prepubertal Gynecomastia – A Case Report

Abstract

Introduction: Peutz-Jeghers syndrome (PJS) is a rare autosomal dominant disorder characterized by gastrointestinal hamartomatous polyps, mucocutaneous pigmentation, and an increased risk of malignancy. Early identification of both classical and atypical manifestations is crucial to prevent severe complications, such as intestinal intussusception, and to reduce oncological risk. Case Report: A 6-year-old male, height +2 SD, with a history of small bowel polyps and melanotic macules on the lips, presented with gynecomastia without palpable testicular masses and Tanner stage I pubertal development. Laboratory findings included prolactin 15 mcg/L (ref: 3.2–20) and dehydroepiandrosterone sulfate 40 mcg/mL (ref: 20–400), with normal liver enzymes. Abdominal ultrasound excluded hepatic and testicular masses. Based on clinical suspicion of PJS, whole-exome sequencing was performed, revealing a pathogenic variant in the STK11 gene, confirming the diagnosis and guiding comprehensive management. Discussion: This case underscores the importance of recognizing early indicators—such as mucocutaneous pigmentation—and atypical endocrine findings like prepubertal gynecomastia, which facilitate timely diagnosis before complications such as intestinal obstruction occur. Key strategies include regular endoscopic surveillance, resection of large polyps (>15 mm), and the use of advanced techniques such as capsule endoscopy and ischemic-controlled polypectomy. A multidisciplinary approach involving genetics, gastroenterology, oncology, and endocrinology is essential to optimize outcomes. Conclusion: Early diagnosis based on clinical evaluation and genetic testing, combined with individualized follow-up, is critical to reducing surgical and oncological complications and improving quality of life in patients with PJS.