Pediatric tumors with multilayered rosettes : a diagnostic dilemma

Authors: Neha Jain, Anshul Singh

DOI: 10.18231/j.ijpo.10711.1611780072

Keywords: Astroblastomas, magnetic resonance imaging, prognosis

Abstract: Background – Diagnosing pediatric CNS tumors with multilayered rosettes can be challenging due to its extreme rarity. Spectrum includes astroblastomas, ependymomas , embryonal tumors with multilayered rosettes which share similar histomorphological features despite being molecularly distinct. Here, we present a case of tumor exhibiting multilayered rosettes, which was later confirmed as astroblastoma. Method – A 2-year-old female presented with a 8-month history of headache, seizures and fever. CT scan and MRI was done which revealed a solid cystic lesion in the left frontal region. Complete surgical resection of the tumor was performed, and tissue was sent for histopathology. Results - Microscopic examination revealed a highly cellular tumor composed of tumor cells arranged in multilayered papillae along with numerous similar multilayered pseudo rosettes and true rosettes. At places, tumor cells are arranged in trabecular pattern composed of thin fibrovascular core and regimented nuclei. Frequent foci of microvascular proliferation and necrosis was seen. Prominent perivascular and stromal sclerosis was seen. Differential diagnosis of astroblastoma, embryonal tumor of multilayered rosettes and ependymomas was made. A complete IHC panel was advised which revealed strong positivity for GFAP, dot like positivity for EMA , focal OLIG2 and synaptophysin positivity and Ki-67 index was high while IDH-1 , L1CAM ,P65 were negative which confirmed diagnosis of astroblastoma. Conclusion- Our case report focuses on astroblastoma, addressing its diagnostic challenges, particularly the critical role of radiological correlation. This correlation is pivotal in distinguishing astroblastoma from similar glial tumors like ependymoma which has subtle histological differences and shared immunohistochemical markers.