Vol.:(0123456789) 1 3 J Neurooncol DOI 10.1007/s11060-017-2586-6 LETTER TO THE EDITOR Extraneuraxial metastases in medulloblastoma: is histology and molecular biology important? Tejpal Gupta 1  · Archya Dasgupta 1  · Sridhar Epari 2  · Neelam Shirsat 3  · Girish Chinnaswamy 4  · Rakesh Jalali 1   Received: 19 February 2017 / Accepted: 23 July 2017 © Springer Science+Business Media, LLC 2017 with ENM from medulloblastoma, this report is limited to 7 of 300 (2.3%) patients with known molecular subgroup affiliation. All relevant patient, disease, and treatment-char- acteristics were retrieved by retrospective review of medi- cal case records and are summarized in Table 1. Median age of the study cohort was 16.5 years (range 3–25 years) at initial diagnosis. 4 (57%) patients had desmoplastic medul- loblastoma, while 3 (43%) patients had large-cell/anaplastic histology. Five of 7 (71%) patients belonged to SHH-sub- group, while the remaining 2 (29%) had subgroup 3 medul- loblastoma. Using conventional risk-stratification, 3 (43%) patients were classified as average-risk disease, while 4 (57%) patients demonstrated high-risk features such as post-operative residual tumor (>1.5 × 1.5 cm 2 ) and/or pres- ence of CNS metastases. All patients had been treated with standard radiotherapy (craniospinal irradiation plus poste- rior fossa boost) followed by adjuvant systemic chemother- apy at initial diagnosis. Most patients were symptomatic at the time of ENM with bone pain and swelling being pre- dominant symptoms. Whole-body 18 F-flouro-deoxy-glu- cose positron emission tomography/computed tomography (FDG-PET/CT) was done in all patients at first suspicion of ENM. None of the patients presented with ENM; it was detected metachronously at a median of 10 months (range 4–33 months) from initial diagnosis with common sites of involvement being bone (71%), bone marrow (43%), and lymph nodes (29%). Liver metastases was detected in two patients (one incidentally on imaging), while pleural, peritoneal, pancreatic, and subcutaneous metastases were detected in a single patient each. Pathologic confirmation of ENM was obtained in all patients but one, to reliably differentiate it from second malignant neoplasm (myelo- dysplasia, leukemia, or lymphoma). Further therapy com- prising of palliative and supportive care was individual- ized based on symptomatology, evolution of disease, prior To the Editor, Novel biological insights in medulloblastoma have recently led to its consensus classification [1] into four distinct molecular subgroups (WNT, SHH, group 3, and group 4). Although relatively rare, it is widely accepted that medul- loblastomas have a higher propensity of spread outside the neuraxis compared to other central nervous system (CNS) tumors with a reported frequency of extraneuraxial metas- tases (ENM) ranging from 2 to 5% [2]. We herein report a single-institutional cohort of patients with ENM from medulloblastoma with reference to histological subtyping and molecular subgrouping. Electronic search of the prospective institutional neuro- oncology database identified a total of 573 patients with histological diagnosis of medulloblastoma registered at our institute between 2005 and 2016. Of these, 300 patients had also undergone molecular subgrouping as part of an Institutional Review Board (IRB) approved research study. Molecular subgroup assignment was based on differential expression of 12 protein-coding genes and nine microR- NAs [3]. Although, our search accounted for 13 patients * Tejpal Gupta tejpalgupta@rediffmail.com; drtejpalgupta@gmail.com 1 Departments of Radiation Oncology, (TMH and ACTREC), Tata Memorial Centre, Kharghar, Navi Mumbai 410210, India 2 Departments of Pathology, (TMH and ACTREC), Tata Memorial Centre, Navi Mumbai, India 3 Neuro-Oncology Lab, ACTREC, Tata Memorial Centre, Navi Mumbai, India 4 Departments of Pediatric Medical Oncology, (TMH and ACTREC), Tata Memorial Centre, Navi Mumbai, India