Atypical teratoid/rhabdoid tumour

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Atypical teratoid/rhabdoid tumour
Diagnosis in short

AT/RT. H&E stain.

LM cellular tumour with small round cells usu. with a prominent nucleolus, rhabdoid cells (eosinophilic granular cytoplasm + eccentric nucleus), mitoses. +/-necrosis (common)
LM DDx primitive neuroectodermal tumour (PNET), medulloblastoma, diffuse astrocytoma, choroid plexus carcinoma, embryonal carcinoma
IHC INI1 -ve, S-100 +ve, EMA +ve, SMA +ve
Site CNS - typically supratentorial

Clinical history usu. <3 years olds, occasionally adults
Prevalence uncommon - esp. in adults
Prognosis very poor

Atypical teratoid/rhabdoid tumour, abbreviated AT/RT, is malignant tumour usually found supratentorially.

It may be written atypical teratoid rhabdoid tumour (abbreviated ATRT) or atypical teratoid-rhabdoid tumour (abbreviated AT-RT).

It should not be confused with the extrarenal malignant rhabdoid tumour.

General

  • Usually supratentorial, occasionally in posterior fossa, case reports of spinal cord.
  • Individuals usually <3 years old, uncommon in adults.[1]
  • Prognosis very poor, but long-term survivors reported.[2]

Microscopic

Features:

  • Cellular.
  • Small round cells usu. with a prominent nucleolus.
  • Rhabdoid cells.
    • Cells with eosinophilic granular cytoplasm + eccentric nucleus.
  • Mitoses.
  • +/-Necrosis (common).

DDx:

Images

www:

IHC

  • INI1-ve (AKA BAF-47, AKA SMARCB1 - the HGNC symbol[3]) - virtually diagnostic (4/4 cases[4]).
    • Endothelial cells +ve control.
  • S-100 +ve (4/4 cases[4]).
    • Few other brain tumours express it.
  • Vimentin +ve - perinuclear condensation (4/4 cases[4]).
  • LIN28 focally +ve [5]

Others:

  • GFAP +ve (focal - in tumour cells).
  • EMA +ve - patchy cytoplasmic (4/4 cases[4]).
  • Smooth muscle actin +ve.(4/4 cases[4]). [6]
  • Cytokeratin +ve.[7]
  • Kir 7.1 occasionally +ve[8]

Molecular

  • Almost all cases associated with SMARCB1 abberations.[9]
  • Single cases with SMARCA4 mutation.[10]
  • Two molecular subgroups:[11]
    • Group 1: usu. supratentorial, ASCL1-positive: high-risk.
    • Group 2: usu. infratentorial, BMP-signalling: very high risk.

See also

References

  1. Kanoto, M.; Toyoguchi, Y.; Hosoya, T.; Kuchiki, M.; Sugai, Y. (Jan 2014). "Radiological Image Features of the Atypical Teratoid/Rhabdoid Tumor in Adults: A Systematic Review.". Clin Neuroradiol. doi:10.1007/s00062-013-0282-2. PMID 24477665.
  2. von Hoff, K.; Hinkes, B.; Dannenmann-Stern, E.; von Bueren, AO.; Warmuth-Metz, M.; Soerensen, N.; Emser, A.; Zwiener, I. et al. (Dec 2011). "Frequency, risk-factors and survival of children with atypical teratoid rhabdoid tumors (AT/RT) of the CNS diagnosed between 1988 and 2004, and registered to the German HIT database.". Pediatr Blood Cancer 57 (6): 978-85. doi:10.1002/pbc.23236. PMID 21796761.
  3. Online 'Mendelian Inheritance in Man' (OMIM) 601607
  4. 4.0 4.1 4.2 4.3 4.4 Ertan, Y.; Sezak, M.; Turhan, T.; Kantar, M.; Erşahin, Y.; Mutluer, S.; Vergin, C.; Oniz, H. et al. (Jun 2009). "Atypical teratoid/rhabdoid tumor of the central nervous system: clinicopathologic and immunohistochemical features of four cases.". Childs Nerv Syst 25 (6): 707-11. doi:10.1007/s00381-009-0811-0. PMID 19212771.
  5. Korshunov, A.; Ryzhova, M.; Jones, DT.; Northcott, PA.; van Sluis, P.; Volckmann, R.; Koster, J.; Versteeg, R. et al. (Dec 2012). "LIN28A immunoreactivity is a potent diagnostic marker of embryonal tumor with multilayered rosettes (ETMR).". Acta Neuropathol 124 (6): 875-81. doi:10.1007/s00401-012-1068-3. PMID 23161096.
  6. Lee, MC.; Park, SK.; Lim, JS.; Jung, S.; Kim, JH.; Woo, YJ.; Lee, JS.; Kim, HI. et al. (Dec 2002). "Atypical teratoid/rhabdoid tumor of the central nervous system: clinico-pathological study.". Neuropathology 22 (4): 252-60. PMID 12564764.
  7. Lee, MC.; Park, SK.; Lim, JS.; Jung, S.; Kim, JH.; Woo, YJ.; Lee, JS.; Kim, HI. et al. (Dec 2002). "Atypical teratoid/rhabdoid tumor of the central nervous system: clinico-pathological study.". Neuropathology 22 (4): 252-60. PMID 12564764.
  8. Schittenhelm, J.; Nagel, C.; Meyermann, R.; Beschorner, R. (Oct 2011). "Atypical teratoid/rhabdoid tumors may show morphological and immunohistochemical features seen in choroid plexus tumors.". Neuropathology 31 (5): 461-7. doi:10.1111/j.1440-1789.2010.01189.x. PMID 21276081.
  9. Hasselblatt, M.; Isken, S.; Linge, A.; Eikmeier, K.; Jeibmann, A.; Oyen, F.; Nagel, I.; Richter, J. et al. (Feb 2013). "High-resolution genomic analysis suggests the absence of recurrent genomic alterations other than SMARCB1 aberrations in atypical teratoid/rhabdoid tumors.". Genes Chromosomes Cancer 52 (2): 185-90. doi:10.1002/gcc.22018. PMID 23074045.
  10. Hasselblatt, M.; Gesk, S.; Oyen, F.; Rossi, S.; Viscardi, E.; Giangaspero, F.; Giannini, C.; Judkins, AR. et al. (Jun 2011). "Nonsense mutation and inactivation of SMARCA4 (BRG1) in an atypical teratoid/rhabdoid tumor showing retained SMARCB1 (INI1) expression.". Am J Surg Pathol 35 (6): 933-5. doi:10.1097/PAS.0b013e3182196a39. PMID 21566516.
  11. Torchia, J.; Picard, D.; Lafay-Cousin, L.; Hawkins, CE.; Kim, SK.; Letourneau, L.; Ra, YS.; Ho, KC. et al. (May 2015). "Molecular subgroups of atypical teratoid rhabdoid tumours in children: an integrated genomic and clinicopathological analysis.". Lancet Oncol 16 (5): 569-82. doi:10.1016/S1470-2045(15)70114-2. PMID 25882982.