Association of Klinefelter Syndrome and Abdominal Teratoma: A Case Report By Piotr Czauderna, Czeslaw Stoba, Barbara Wysocka, and Mariola lliszko Gdafisk, Poland Extragonadal germ cell tumors are rare. The association with Klinefelter syndrome has become observed recently. A case of an II-month-old infant with Klinefelter syndrome and a retroperitoneal mature teratoma is presented. In the tumor and lymphocytes, a 47,XXY karyotype was found. The asso- ciation of Klinefelter syndrome with germ cell tumors and its K LINEFELTER SYNDROME is the most common form of male hypogonadism with a characteristic chromosomal abnormality of 47,XXY.l The classical clinical features are small testes, eunuchoidism, azoosper- mia, gynecomastia, and occasionally mental retardation. Recently, an association between Klinefelter syndrome and germ cell tumors became well recognized,le3 mostly reported in adults and adolescents.1,2 We describe an infant with the association of Klinefelter syndrome and abdominal teratoma. CASE REPORT An 1 l-month-old boy was admitted to a local hospital with unrest, constipation, and emesis. An obstructive ileus was suspected, but physical examination showed a palpable mass in the left hypochon- drium, crossing the midline and reaching into the left iliac fossa. Laboratory values showed elevated sedimentation rate, 20/50; leukocy- tosis, 13.800; and anemia (hemoglobin, 10.3g%; red blood count, 3.94 G/L; hematocrit, 24%). Intravenous pyelography showed compression of pelvico-calyceal system of the left kidney by a retroperitoneal tumor with calcifications. An initial diagnosis of neuroblastoma was made, and the patient was referred to our tertiary center. Abdominal ultrasound scan showed a compression of the left kidney and superior displacement of the spleen and stomach by a large prevertebral mass (11 X 11 X 10.6 cm) with different echogenicity of internal components (from solid to cystic), suggesting a teratoma (Fig 1). These findings were confirmed by an upper gastrointestinal series. Laboratory tests found no evidence for a neuroblastoma: vanillylmandelic acid (VMA), ferritin, and lactic dehydrogenase values were normal. Alpha-fetoprotein and beta human chorion-gonadotropin values were also normal. At laparotomy, a retroperitoneal tumor of semicystic consistency From the Clinic of Pediatric Surgery and the Department of Biology and Genetics of the Medical University of Gdan’sk, Poland. Address reprint requests to Piotr Czauderna, MD> Department of Pediatric Surgery, Medical University of Gdansk, ~1. Nowe Ogrody I-6, 80.803 Gdansk, Poland. Copyright 0 1998 by WB. Saunders Company 0022.34&T/98/3305-0033/03.00/3 774 - possible explanations are discussed. J Pediatr Surg 33:774-775. Copyright o ‘1998 by W.B. Saun- ders Company. INDEX WORDS: Klinefelter syndrome, teratoma, germ cell tumors. (15 X 12 X 7 cm) was found. It displaced the pancreas, left suprarenal gland, stomach, intestines, and compressed the left kidney. The noninfiltrating tumor could be easily resected. On cross section the mass had a mixed appearance: partially solid, respectively multiloculated, or chondroid. Microscopy findings showed a mature teratoma. Cytogenetic examination of the tumofl showed a 47,XXY karyotype. Cytogenetic analysis of peripheral blood lymphocytes showed the same karyotype. The patient showed no other clinical features of the Klinefelter syndrome, probably explained by his young age. Currently, the patient is free of a tumor recurrence at 4 years of age. DISCUSSION Klinefelter syndrome affects 0.6% of the male popula- ti0n.l These patients have an increased risk for neo- plasms, particularly of the breast and germ cells.5 Despite the association between Khnefelter syndrome and germ cell tumors, only few reports are available1-3%6 Fig 1. Ultrasound picture of the well-delineated, round tumor of mixed echogenicity (arrowheads) located prevertebrally and to the left. Journai ofPediatric Surgery,Vol33, No 5 (May), 1998: pp 774-775