SMARCB1-deficient sinonasal carcinoma

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SMARCB1-deficient sinonasal carcinoma (also INI-1-deficient carcinomas of the sinonasal tract) is a rare malignant tumour of the head and neck with loss of SMARCB1 staining.[1]

General

  • Rare - large series from 2017 has 39 cases.[1]
  • Large age range (19-89 years old).
  • Often present at high stage T3 or T4.
  • Aggressive clinical course.

Gross

  • Most often in ethmoid sinus +/- nasal cavity.

Microscopic

Features:[1]

  • Pagetoid spread of plasmacytoid or rhabdoid cells.
  • Cyst/pseudocyst like spaces.
  • Lack squamous dysplasia.
  • Lack of carcinoma-in-situ.

DDx:

IHC

  • SMARCB1 (INI1) -ve (definitional).[1]
  • Pankeratin +ve ~ 97% +ve.[1]
  • CK5 +ve ~ 64% +ve.[1]
  • P63 +ve ~ 55% +ve.[1]
  • CK7 -ve/+ve ~ 48% +ve.[1]
  • NUT -ve.[1]

See also

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Agaimy, A.; Hartmann, A.; Antonescu, CR.; Chiosea, SI.; El-Mofty, SK.; Geddert, H.; Iro, H.; Lewis, JS. et al. (Apr 2017). "SMARCB1 (INI-1)-deficient Sinonasal Carcinoma: A Series of 39 Cases Expanding the Morphologic and Clinicopathologic Spectrum of a Recently Described Entity.". Am J Surg Pathol 41 (4): 458-471. doi:10.1097/PAS.0000000000000797. PMID 28291122.