Journal of the Medical Association of Thailand Vol 104, No 10:OCTOBER 2021 0125-2208 104 10 2021 Oct Clinical Characteristic and Molecular Subgroups of Thai Pediatric Medulloblastomas at Queen Sirikit National Institute of Child Health 1648-57 EN Paveen Tadadontip Somruetai Shuangshoti Original Article To determine the correlation between clinical characteristics and molecular subgroups of medulloblastoma (MB) in Thai pediatric patients at the Queen Sirikit National Institute of Child Health (QSNICH), Thailand. MB specimens operated between 2004 and 2018 were classified by Nanostring into four molecular subgroups, including Wingless signaling pathway (WNT), Sonic Hedgehog signaling pathway (SHH), Group 3, and Group 4. For the present cases, the clinical records were retrospectively analyzed. Twenty-two MB cases with complete clinical records were analyzed. Group 4 was the most common molecular subgroup (31.82%), followed by WNT (27.27%), SHH (22.73%), and Group 3 (18.18%). The histologic subtypes included 18, three, and one cases of classic MB, MB with extensive nodularity (MBEN), and large cell MB, respectively. All SHH MBs were found in infants. All MBENs belonged to SHH subgroup, and the large cell MB was Group 3. All six WNT MB cases did not experience tumor recurrence. Five-year cause specific survival rates were 100% in WNT, 60% in SHH, 57.1% in Group 4, and 0% in Group 3. Five-year recurrence-free survival rates were 100% in WNT, 42.9% in Group 4, and 0% in SHH and Group 3. MB is a heterogeneous disease. Classification of MB, especially at the molecular subtype, is helpful for the management and prognostication. Medulloblastoma; Molecular subgroupDOI: doi.org/10.35755/jmedassocthai.2021.10.12989Received 24 May 2021 | Revised 27 August 2021 | Accepted 31 August 2021