Smooth Muscle Proliferation in Hamartomatous Polyps Mimicking Prolapse in Pediatric Patients with PTEN Hamartoma Tumor Syndrome

Abstract

Abstract Introduction/Objective In the field of pediatric pathology, it is vital to find recognize cases that could be associated with cancer predisposition syndromes. PTEN hamartoma tumor syndrome (PHTS) is an inherited set of disorders caused by germline inactivating mutations of the PTEN tumor suppressor gene. In the GI tract, PHTS is associated with hamartomatous polyps that can display smooth muscle overgrowth. We therefore present a series of three cases of colonic polyps with smooth muscle overgrowth, mimicking prolapse, in pediatric patients with PTEN mutations. Methods/Case Report The first case is a 19-year-old male with PHTS who underwent colonoscopy due to hematochezia. Two pedunculated polyps were removed from the transverse and descending colon. Both polyps showed prominent smooth muscle and ganglion cells in the lamina propria. In the second case, a 9-year-old male with PHTS also underwent colonoscopy due to hematochezia. At least 20 sessile 2-4mm polyps were present in the colon. Histology showed smooth muscle proliferation and ganglion cells in the lamina propria. The third case is a 13-year-old male with undiagnosed PHTS, but a history of Chron’s disease, trichilemmoma, and plantar wart like lesions. He underwent upper and lower endoscopy for Chron’s disease assessment. Three polyps were removed from the descending colon. One was a juvenile polyp while the other two showed prominent smooth muscle proliferation and ganglion cells in the lamina propria. Results (if a Case Study enter NA) NA Conclusion Histologically, all hamartomatous polyps had smooth muscle overgrowth, confirmed by SMA immunostain, which could easily be confused with prolapse type changes such as in solitary rectal ulcer syndrome. The key in distinguishing between the two is by recognizing ganglion cells within the lamina propria, confirmed by S100 immunostain. Additional clues include identifying mucosal ganglion cells, disarray of crypt architecture, and fibromuscular proliferation as well as considering the location and number of polyps. It is vital for pathologists to recognize the differential diagnosis of polyps with smooth muscle proliferation, especially in pediatric populations where a diagnosis of cancer predisposition syndromes may not be established. Furthermore, is important to discuss pursuing PTEN genetic testing with clinical colleagues as it has immense medical implications and requires a thorough future medical following.