Cellular cannibalism in cytology - a distinctive feature of large cell/anaplastic medulloblastoma in a pediatric case

Sep 29, 2026

Clinical vignette describing intraoperative cytology in a 5-year-old with a right lobar expansive cerebellar lesion. The case uses squash cytology stained with toluidine blue to rapidly assess cellularity, mitotic activity, and scattered apoptotic figures. Microscopy shows marked high cellularity with salt-and-pepper chromatin and cellular cannibalism, leading to a diagnosis of MB-LC/A. Histology and immunohistochemistry confirm large cell/anaplastic medulloblastoma, emphasizing how cellular cannibalism can distinguish the anaplastic variant and support surgical decision-making.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages2

Reading Time5 min

AccessFree to download

Clinical Vignette

Background: medulloblastoma and MB-LC/A

Case description and cytologic findings

Immunohistochemistry and diagnostic confirmation

Clinical significance of intraoperative cytology

Data availability and conflicts

© 2025 Greater Poland Cancer Centre. Published by Via Medica. All rights reserved. e-ISSN 2083–4640 ISSN 1507–1367 ISSN: 1507–1367 CLINICAL VIGNETTE Reports of Practical Oncology and Radiotherapy 2025, Volume 30, Number 5, pages: 732–733 DOI: 10.5603/rpor.108008 Submitted: 30.05.2025 Accepted: 06.08.2025 Cellular cannibalism in cytology: a distinctive feature of large cell/anaplastic medulloblastoma in a pediatric case Gabriele Gaggero 1, Chiara Trambaiolo Antonelli 1, Gianluca Piatelli 2, Claudia Milanaccio 3 1Pathology Unit, IRCCS Istituto Giannina Gaslini, Genova, Italy 2Neurosurgery Unit, IRCCS Istituto Giannina Gaslini, Genova, Italy 3Neuro-oncology Unit, IRCCS Istituto Giannina Gaslini, Genova, Italy Keywords: cellular cannibalism; medulloblastoma; pediatric Rep Pract Oncol Radiother 2025;30(5):732–733 Medulloblastoma (MB) is the second most common malignant tumor of the central nervous system (CNS) in childhood, accounting for 20% of all intracranial tumors. MB is often associated with several inherited syndromes and can arise in different locations, the cerebellum being one of the most frequent [1] . From both a histological and molecular point of view, MB is an extremely heterogeneous group, even with different responses to therapy depending on the subgroup [2]; however, MB are collectively classified as grade 4 embryonal tumors by the World Health Organization 2021 classification of CNS tumors (WHO-CNS2021) . Among the histologic subtypes, the large cell/anaplastic variant (MBLC/A) is one of the most aggressive, characterized by a high mitotic/carioretic index and a distinctive cytologic feature: cell wrapping, also known as cellular cannibalism. Even today, despite the rise of the emerging “omic” sciences, intraoperative diagnosis of a brain mass can significantly alter the surgical strategy, with intraoperative cytological examination playing a crucial role. The cytological case described here is placed in this context. The image presented here refers to the case of a 5-year-old child with a right lobar expansive cerebellar lesion whose neuro-radiologic imaging (MRI) showed features suggestive of high cellularity. The patient underwent surgery and an intraoperative evaluation was decided. A cytological specimen was obtained by the squash method (a technique used in cytology in which a sample of cells is prepared by squeezing or pressing tissue or fluid onto a microscope slide) and rapidly stained with toluidine blue. Microscopy revealed a neoplasm with markedly increased cellularity consisting of cells of various sizes ranging from medium to large. These cells had scant cytoplasm and salt-and-pepper chromatin. The tumor was characterized by scattered images of cellular cannibalism (Fig. 1AB), numerous mitoses (Fig. 1C), and frequent apoptotic figures. These findings were consistent with a primitive small round cell tumor, and the cellular cannibalism led to the diagnosis of MB-LC/A. The mass was excised and histology confirmed the diagnosis both morphologically (Fig. 1D) and immunohistochemically: GFAP-, Olig2-, synaptophysin+ (focal), beta-catenin+, INI1+ (retained nuclear expression), p53+ (nuclear expression in scattered elements), Ki-67 extremely high (proliferation index of 80%) . Intraoperative cytologic evaluation of CNS lesions has important implications for diagnosis and treatment planning [3] . MB-LC/A, which is Address for correspondence: Gabriele Gaggero, Largo Gerolamo Gaslini, 5 – 16147 Genoa, Italy; [e-mail: gabriele.gaggero@outlook.it](e-mail: gabriele.gaggero@outlook.it) This article is available in open access under Creative Common Attribution-Non-Commercial-No Derivatives 4.0 International (CC BY-NC-ND 4.0) license, allowing to download articles and share them with others as long as they credit the authors and the publisher, but without permission to change them in any way or use them commercially 732 [https://journals.viamedica.pl/rpor](https://journal

FAQs

What cytological feature was key for diagnosing MB-LC/A in this case?

Scattered cellular cannibalism was a distinctive finding, observed alongside high cellularity and mitotic activity, guiding the MB-LC/A diagnosis.

How was the intraoperative cytology sample prepared and stained?

A cytological specimen was prepared by the squash method and rapidly stained with toluidine blue for immediate microscopy.

What was confirmed after surgery regarding the tumor type?

Histology and immunohistochemistry confirmed large cell/anaplastic medulloblastoma, including persistent presence of cellular cannibalism.

Sep 29, 2026

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