Cytomorphologic characteristics, differential diagnosis and utility during intraoperative consultation for medulloblastoma

Acta Cytol. 2007 Mar-Apr;51(2):183-92. doi: 10.1159/000325713.

Abstract

Objective: To study the cytologic findings that differentiate LC/A and non-LC/A (NLCA) types.

Study design: Cytologic smears, prepared during intraoperative consultation (IOC) of 43 cases of pure histologic type, defined as > 80% of the tumor being composed of 1 of 3 major histologic types--classic, nodular and LC/A--were reviewed and graded semiquantitatively (0-3+) for 14 cytologic features: cellularity, nuclear streaming, endothelial proliferation, necrosis, lymphoglandular bodies, rosette formation, apoptosis, nuclear cannibalism, pleomorphism, macronucleoli, paranuclear inclusions, cytoplasmic vacuoles, mitoses and multinucleation. The grades were compared between the 2 histologic groups, LC/A vs. NLCA, as well as between the preparation methods, squash vs. touch (TP). Values of p < 0.05 were accepted as statistically significant.

Results: "Cell wrapping" (cannibalism), pleomorphism, macronucleoli, apoptosis, mitoses and cytoplasmic vacuoles were more significantly observed in LC/A than in NLCA.

Conclusion: Intraoperative cytologic evaluation of these cytologic parameters allows distinction between LC/A and NLCA, which can be prognostically useful during IOC. Rosette formation, the histologic hallmark of classic medulloblastoma, is not a discriminator. Given the fewer artifacts and sufficient cellularity, TP is the preferred method of cytologic preparation.

MeSH terms

  • Adolescent
  • Biopsy / methods
  • Biopsy / standards
  • Cell Nucleus / pathology
  • Cell Proliferation
  • Cerebellar Neoplasms / classification*
  • Cerebellar Neoplasms / pathology*
  • Cerebellar Neoplasms / surgery
  • Cerebellum / pathology*
  • Cerebellum / physiopathology
  • Cerebellum / surgery
  • Child
  • Child, Preschool
  • Cytoplasm / pathology
  • Diagnosis, Differential
  • Diagnostic Errors / prevention & control
  • Endothelial Cells / pathology
  • Female
  • Humans
  • Infant
  • Intraoperative Period
  • Male
  • Medulloblastoma / classification*
  • Medulloblastoma / pathology*
  • Medulloblastoma / surgery
  • Predictive Value of Tests
  • Prognosis
  • Referral and Consultation
  • Retrospective Studies