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Meningeal tumors are rare in childhood, comprising less than 4.2% of all pediatric primary intracranial tumors.1 Fourteen histological subtypes of meningiomas exist in the World Health Organization (WHO) classification system.2 Chordoid meningioma (CM) is a rare meningiomal variant characterized histologically by features that mimic chordoma and other chordoid neoplasms.2 Chordoid meningiomal tumors tend to exhibit local recurrence and aggressive behavior, although they typically show morphologically benign features. In a tuberous sclerosis complex (TSC) patient, hamartomas can occur in multiple organs and cause diverse clinical symptoms. Cortical tubers, subependymal nodules (SENs) and subependymal giant cell astrocytomas (SEGAs) are representative lesions of TSC and can be detected by magnetic resonance imaging (MRI) of the brain.3 SEGA lesions have been found to occur in approximately 6.1% to 18.5% of TSC patients, and account for 90% of all intracranial tumors associated with TSC.4 SEGA lesions are commonly located in the foramen of Monro or the periventricular region,5 and can cause loss of vision, papillary edemas, intracranial calcification, and hydrocephalus.6 The primary method for treating SEGA lesions consists of surgical resection of the tumors; complete and early surgical removal of tumors has been shown to be the most important prognostic factor.6 Childhood CM has been shown to account for only ~0.5-1% of all meningiomas, with intraventricular occurrence of CM reported in only 27 children to date.2,7 Also, CM has not been reported in any TSC patients to date. Here we report a case of intraventricular CM, which appeared highly similar to SEGA in brain MRI scans, in a child with TSC.

Hemangioblastomas of the central nervous system (CNS) are benign tumors that most commonly occur in the cerebellum, followed by the brainstem and spinal cord [1]. Supratentorial location is extremely rare [2]. CNS hemangioblastomas can occur sporadically or in association with von Hippel-Lindau disease [2]. Histologically, the tumors are composed of two main components: large and vacuolated stromal cells and numerous thinwalled vessels. Due to the characteristic lipid-containing cytoplasm and foci of pleomorphic nuclei, the differential diagnosis of hemangioblastoma from some other malignant tumors, such as clear cell renal cell carcinoma (RCC), adrenal cortical carcinoma and paraganglioma, remains challenging, especially in cellular variants. Hyaline globules can be found in many different tumors and benign tissues [3], including CNS hemangioblastomas, and they contribute to the diagnostic difficulty. Herein, we report a case of sporadic supratentorial hemangioblastoma with unusual features and discuss the differential diagnosis of CNS hemangioblastoma.

Neuroblastic tumors (NTs) are the most common extracranial solid tumors in children with highly variable biologic features and clinical outcomes.1,2 The natural history of NTs range from spontaneous regression to rapid and potentially fatal progression. Therefore, treatment plans may vary from close observation to multimodal interventions, including surgery, chemotherapy, and radiotherapy, according to individual clinical course.3,4 Due to the heterogeneous clinical courses in one disease entity, it is important to identify poor prognostic features of NTs and treat such cases aggressively. Among many prognostic models, histopathologic classifications are one of the most important factors.5 The International Neuroblastoma Pathology Classification (INPC) is a systematic age-linked histopathological indicator which links morphology to clinical presentation and tumor genetics.6 INPC classifies NTs into six different histological subtypes: 1) neuroblastoma (NB), undifferentiated (Schwannian stroma-poor); 2) NB, poorly differentiated (Schwannian stroma-poor); 3) NB, differentiating; 4) ganglioneuroblastoma (GNB), intermixed (Schwannian stroma-rich); 5) ganglioneuroma (GN) (Schwannian stroma-dominant); and 6) GNB, nodular (composite Schwannian stroma-rich/stroma-dominant and stroma poor).7,8 Although primary sites of NTs have been the target of extensive pathological review and analyses, there is a paucity of literature characterizing metastatic sites, especially bone marrow. Indeed, bone marrow metastasis is an important poor prognostic factor, and marrow biopsy is incorporated as a part of routine diagnosis and staging work-up of NTs.9 The aims of this study are to evaluate the histological features of NTs metastasized to bone marrow metastasis in comparison to the primary tumor and to compare histological characteristics of metastatic NTs in bone marrow before and after chemotherapy.