A PTEN Mutation in Cowden Syndrome Patient with Forearm Intramuscular Hemangioma-＂A Case Report and Literature Review＂

Background: Cowden syndrome (CS) is a hereditary autosomal dominant syndrome with a marked variable expression. The patient with CS has a high risk of developing breast, thyroid and endometrial cancers. It has been demonstrated a close relationship between Cowden syndrome and PTEN gene mutation. Aim and Objectives: We present a case with left forearm tumor and thyroid tumor. A genetic study showed the patient has Cowden syndrome. Materials and Methods: An Asian patient, 18-year-old male, who sustained a progressively growing elastic left forearm mass for one year and an incidental finding of a lobulated right thyroid tumor extending to left neck, and a left subclavian fossa lipoma. The patient received right thyroid lobectomy, left neck lipoma excision and left forearm hemangioma excision. Specimens were all sent to pathologic study and the blood sample, normal tissue and left forearm tumor were sent for PTEN survey. Results: Postoperatively, the patient did not present any extrinsic or intrinsic functional deficit over left forearm and hand. Right thyroid mass showed follicular adenoma and left forearm was intramuscular hemangioma. Abnormal expression of exon 2 and exon 5 over chromosome 10 was noted. One deletion at 159^(th) base pair in cDNA of exon 2 was also noted. T/A cloning sequence in exon 5 showed deletion at 340 ~ 344^(th) base pair cDNA in tumor tissue. All these clues were deduced to a PTEN gene mutation in Cowden syndrome with the correlated clinical presentations. Conclusion: Cowden syndrome is correlated with multiple tumor formation. This paper showed the correlation with forearm tumor and Cowden syndrome.