Nuclear β-Catenin Expression is Frequent in Sinonasal Hemangiopericytoma and Its Mimics

Abstract

Sinonasal hemangiopericytoma (HPC) is a tumor showing pericytic myoid differentiation and which arises in the nasal cavity and paranasal sinuses. CTNNB1 mutations appear to be a consistent aberration in sinonasal HPC, and nuclear expression of b-catenin has been reported. Our aim was to evaluate the frequency of b-catenin expression in sinonasal HPC and its histologic mimics in the upper aerodigestive tract. Cases were retrieved from the surgical pathology and consultation files. Immunohistochemical staining for b-catenin was performed on 50 soft tissue tumors arising in the sinonasal tract or oral cavity, and nuclear staining was recorded semiquantitatively by extent and intensity. Nuclear reactivity for b-catenin was present in 19/20 cases of sinonasal HPC; 17 showed moderate-to-strong multifocal or diffuse staining, and 2 had moderate focal nuclear reactivity. All solitary fibrous tumors (SFT) (10/10) showed focal-to-multifocal nuclear staining, varying from weak to strong in intensity. Most cases of synovial sarcoma (9/10) showed nuclear b-catenin expression in the spindle cell component, ranging from focal-weak to strong-multifocal. No cases of myopericytoma (0/10) showed any nuclear b-catenin expression. bcatenin expression is prevalent in sinonasal HPC, but is also frequent in SFT and synovial sarcoma. Our findings indicate that b-catenin is not a useful diagnostic tool in the evaluation of spindle cell tumors with a prominent hemangiopericytoma-like vasculature in the sinonasal tract and oral cavity, and that definitive diagnosis relies on the use of a broader immunohistochemical panel.

Solitary Fibrous Tumors of the Head and Neck

“…Moreover, lesions previously designated as giant cell angiofibroma (GCA) and orbital fibrous histiocytoma (OFH) have been recently proposed to be part of the spectrum of SFTs (24) and may alter the overall anatomic distribution or prognosis. Conversely new molecular data confirm the exclusion from SFT of head and neck specific lesions, including the true pericytic neoplasm, glomangiopericytoma or sinonasal HPC (25, 26), has been recently found exhibit CTNNB mutation and nuclear accumulation of β-catenin (27). Additionally, the recently described, biphenotypic low-grade sinonasal sarcoma with neural and myogenic features (28, 29), deserves mention as a newer entity outside of the SFT spectrum.…”

Sinonasal Tract Solitary Fibrous Tumor: A Clinicopathologic Study of Six Cases with a Comprehensive Review of the Literature

“…Glomangiopericytoma, however, lacks the variable cellularity and [65,72,76,77]. While nuclear accumulation of β-catenin is consistently present in glomangiopericytoma secondary to the presence of CTNNB1 mutations [78], it should be noted that this finding is not unique to glomangiopericytoma, as nuclear β-catenin expression has also been frequently observed in SNT SFT [79]. Nasopharyngeal angiofibroma has a distinctive clinical presentation, affecting only males, while SNT SFT typically occur in middle age adults.…”

Immunohistochemical correlates of recurrent genetic alterations in sarcomas

“…However, 10%‐20% of cases show negative staining; this does not preclude diagnosis. Immunohistochemistry for beta‐catenin can also be used to support the diagnosis of sinonasal hemangiopericytoma (glomangiopericytoma), which consistently harbors CTNNB1 activating mutations, although aberrant nuclear staining is also commonly seen in histologic mimics …”

“…Immunohistochemistry for beta-catenin can also be used to support the diagnosis of sinonasal hemangiopericytoma (glomangiopericytoma), which consistently harbors CTNNB1 activating mutations, 93,94 although aberrant nuclear staining is also commonly seen in histologic mimics. 95 6 | MARKERS DISCOVERED THROUGH GENE EXPRESSION PROFILING 6.1 | DOG1 DOG1 ("discovered on GIST-1"; also referred to as anoctamin-1/ ANO1) is a useful second-line immunohistochemical marker for GIST, which was first identified by gene expression profiling. 96 It is most valuable when applied to the 5% of GIST that are negative for KIT (CD117).…”