Qap (Anatomical Pathology) 

QAP Peer Review

AP267
Case History: F/9, presenting with headache. Accompanied by nausea and vomiting. CT scan showed 7.5 cm enhancing tumor in right frontal and anterior parietal lobes
Intended diagnosis: Atypical teratoid/rhabdoid tumor. Contributed by:JKCC
Code Diagnosis Comment Score
anonymous Atypical teratoid/rhabdoid tumour (100%) Immunohistochemically, tumour cells are positive for EMA, vimentin, SMA, sometimes express GFAP and neurofilament. Cytogenetic analysis will show monosomy or deletion of chromosome 22.  100
anonymous AT/RT(Atypical teratoid/rhabdoid tumor) nil  100
anonymous Anaplastic ependymoma Differential diagnosis: embryonal tumour including atypical teratoid rhabdoid tumour, supratentorial PNET and ependymoblastoma. Immunostains with GFAP, EMA and INI-1.  80
anonymous Atypical Teratoid/rhabdoid tumor Immunostaining for INI1 (loss of staining) Genomic study for INI1 gene delection  100
anonymous EPENDYMOMA. 100% CONFIRM BY GFAP positivity. The less likely differential is atypical teratoid/rhabdoid tumor which will show loss of nuclear staining for INI-1.  80
anonymous Atypical teratoid/rhabdoid tumor. 100% Do INI1 which will show loss of nuclear staining.  100
anonymous DDx: Primitive neuroectodermal tumour (40%), Atypical teratoid rhabdoid tumour (40%), Malignant Ependymoma (20%) Require ancillary studies (immunostaining, cytogenetics, molecular studies) for definitive tumour typing  80
anonymous Malignant high grade tumour, favour anaplastic ependymoma (80%) with differential diagnosis include primitive neuroectodermal tumour (PNET) (20%) nil  50
anonymous atypical teratoid/rhabdoid tumour nil  100
anonymous Primary malignant tumor, differential diagnosis: (1) Anaplastic ependymoma; (2) Atypical teratoid/ rhabdoid tumor. Immunohistochemistry: SMA, EMA, GFAP.  80
anonymous Ependymoma nil  50
anonymous Anaplastic ependymoma (WHO grade 3) nil  50
anonymous Anaplastic ependymoma (90%), atypical teratoid/rhabdoid tumour (10%). Immunostaining for GFAP, EMA will be helpful for tumour typing, and Ki67 to establish the proliferative index.  80
anonymous Anaplastic ependymoma, DDX: Atyical teratoid/ Rhabdoid tumour, take more blocks for other component (100% Probability). nil  80
anonymous Malignant tumor (100%), differential diagnoses include atypical teratoid/rhabdoid tumor (50%) and primitive neuroectodermal tumor (50%). Perform immunostains including vimentin, EMA, smooth muscle actin, GFAP, CD99, synaptophysin and INI1. There is loss of INI1 expression in atypical teratoid/rhabdoid tumor.  90
anonymous Anaplastic ependymoma nil  50