Case Report: Rare Presentation of Mixed Germ Cell Tumor in an Infant

The estimated incidence of pediatric testis tumor is 0.5–2.0 per 100,000 children, accounting for 1–2% of all pediatric tumors. Mixed germ cell tumors (MGCT) in prepubertal males are exceedingly rare, with only one previous case report found in the literature. We report a case of a MGCT in an infant. For prepubertal males, GCTs typically present with a painless scrotal mass, though trauma, testis torsion and hydrocele are also common presentations. Similar to such tumors in postpubertal males, ultrasonography, computed tomography, and tumor markers are integral to determine the best treatment. The patient described in this report presented with a painless scrotal mass. Following orchiectomy, the patient was found to have MGCT that was limited to the testis. With prudent management, these patients tend to have favorable prognoses.

A rare giant mixed germ cell tumor of the pineal region with immature elements: Case report and review of the literature

The diagnosis and management of mixed intracranial germ cell tumors may be complicated by the diversity present within this tumor category. Mixed germ cell tumors demonstrate variable natural histories which may be altered by the inclusion of even the most minute immature histological components. We report the case of an 18-year-old male who presented with a 3-month history of progressive headache and nausea leading to lethargy. Imaging revealed a giant pineal region mass extending superiorly from the roof of the fourth ventricle into the lateral ventricle, with resultant obstructive hydrocephalus. No spinal lesions were noted. Following gross total resection, the patient experienced marked improvement. Pathologic analysis identified an uncommon tumor composition: mature teratoma (96%), immature teratoma (2%), and germinoma (2%). Guided by the immature component, chemotherapy and radiation were added post-operatively to provide this patient with the greatest chance of long-term survival. Intracranial pathology, including germ cell tumors, should be included in the differential for any young patient presenting with new and progressive headache and nausea. This case emphasizes the benefit of a multimodal approach to mixed germ cell tumors of the pineal region and the importance of careful pathologic review of all submitted material.

Clinical significance of Kelch-like protein 11 antibodies

ObjectiveTo report the clinical and oncologic associations of antibodies against Kelch-like protein 11 (KLHL11-ab), recently suggested as biomarkers of a paraneoplastic brainstem cerebellar syndrome associated with testicular seminoma, and to determine the value of immunohistochemistry as a screening technique.MethodsStudies included 432 sera or CSF from 329 patients with paraneoplastic (157) or autoimmune neurologic syndromes (172); 63 with neurologic symptoms and benign teratomas; 28 with small-cell lung cancer, and 12 healthy subjects. KLHL11-abs were examined using a cell-based assay (CBA) with HEK293 cells transfected with a human KLHL11 clone. The CBA specificity was confirmed by immunoprecipitation. All positive samples were examined by immunohistochemistry on rat brain sections.ResultsKLHL11-abs were detected in 32 patients by CBA, and patients' antibodies immunoprecipitated KLHL11. Using rat brain immunohistochemistry, only 7 samples (22%) were positive. Patients' median age was 28 years (range 9–76 years), and 16 (50%) were women. Tumors were identified in 23/32 (72%) patients, including 14 teratomas and 7 seminomas or mixed germ cell tumors. Thirteen (41%) patients had cerebellar ataxia (7) or encephalitis with brainstem cerebellar symptoms (6), 7 (22%) anti-NMDA receptor (NMDAR) encephalitis (5 with ovarian teratoma), 5 (16%) opsoclonus-myoclonus, 3 (9%) limbic encephalitis, and 4 (12%) diverse neurologic symptoms (3 with benign teratomas). Concurrent autoantibodies occurred in 14 (44%) patients (7 anti-NMDAR, 6 Ma2, and 1 Hu).ConclusionsKLHL11-abs associate with a spectrum of syndromes and tumors wider than those previously reported; 44% of patients have concurrent neuronal antibodies, some of them (anti-NMDAR) pathogenically relevant. Brain immunostaining is not useful for routine screening of KLHL11-abs.

Malignant Transformation of Testicular Teratoma to PNET, Adenocarcinoma, and Osteosarcoma with Complete Remission after Surgery and Combination Chemotherapy in a Young Adult Male

Mixed germ cell tumors (GCT) with teratoma components can transform into somatic malignancies which can include histologies outside of traditional germ cell lineages. We describe a case of an 18-year-old man with a metastatic testicular GCT with both mature and immature teratoma components containing malignant transformation into multiple histologies including PNET in the primary testicular tumor and osteosarcoma in a separate pulmonary metastatic lesion. Management with targeted chemotherapy resulted in a durable remission. This is the first reported case that we know of a patient with primary PNET malignant transformation with subsequent metastatic transformation to osteosarcoma.

Growing teratoma syndrome: Is it a subtype of germ-cell tumors or another entity?

e16040 Background: Growing teratoma syndrome(GTS ) is a process presenting with growing masses despite normal tumor marker levels(TML) after chemotherapy in non-seminomatous germ cell tumors (NSGCT). Methods: GTS patients between 2000-2016 were evaluated for clinicopathological features and survival outcomes retrospectively. Results: 17 (6,4%) of 266 NSGCT had GTS. Median follow-up was 57.7 ( 13.8-132.7) months. Median age 27 (17-51) years . Most (n = 14) of them had mixed germ-cell tumors & 12 had mature/immature teratoma in primary pathology at diagnosis. Most (n = 11) of them had stage 3 disease & 10 had high TML (S1-3). 11 GTS patients had good risk NSGCT. All (n = 17) had 4 BEP(bleomycin, etoposide, cisplatin) cycles. Recurrence occured in retroperitoneum (n = 13), lung (n = 3) & brain (n = 1). They were considered as GTS since they had normal TML despite growing masses. 5 patients were referred to surgery without salvage chemotherapy and they had teratoma on postoperative surgery. 13 had surgery after salvage chemotherapy (TIP: taxane, ifosfamide, platin) but 4 had unresectable disease and they had clinical benefit with interferone α2b. Two operated patients had diffuse necrosis on pathology whereas others had documented teratoma. Median DFS was 12.3 ( 5.7-18.8) months whereas median OS was 64.8 (15.5-158) months. 3 patients had no recurrence after surgery for GTS. 9 had salvage chemotherapy (gemcitabine/oxaliplatin, TIP) for NSGCT metastatic lesions with TML elevation and 2 of them had autolog stem cell transplantation. Conclusions: GTS is rare in NSGCT, but it should be considered in NSGCT patients with both growing masses & normal TML after primary treatment approach. GTS patients surgery with resectable masses should be referred to surgery since teratoma without viable tumor seems to have less benefit from chemotherapy and/or radiotherapy. Interferon α2b might be an option in unresectable GTS.