Sinonasal Collision Tumor of Glomangiopericytoma and B-Cell Lymphoma
- Author:
Christian Joseph B. Cruzado
1
;
Alejandro E. Arevalo
1
;
Celestine G. Trinidad
2
Author Information
- Publication Type:Other Types
- Keywords: Glomangiopericytoma
- MeSH: Nasal Cavity; Neoplasms; Lymphoma, B-Cell
- From: Philippine Journal of Pathology 2026;(75th PSP Research Competition Abstracts):1-
- CountryPhilippines
- Language:English
-
Abstract:
Introduction:Sinonasal collision tumors are exceptionally rare, and glomangiopericytoma (GPC) is an uncommon perivascular myoid neoplasm accounting for less than
0.5% of sinonasal tumors. GPC can mimic other spindle-cell tumors, and recognition
of perivascular morphology with immunohistochemistry with SMA, nuclear and
cytoplasmic β-catenin are essential. Sinonasal B-cell lymphomas are also uncommon
and may be difficult to classify in fibrotic biopsies; the coexistence of these two entities
appears exceedingly unusual.
Case Description:A 69-year-old man presented with progressive left-sided nasal symptoms. Endoscopy showed an obstructing left nasal cavity mass. Biopsy showed two components: a spindle-cell proliferation with thin-walled branching (“staghorn”) vessels and perivascular hyalinization, and scattered monomorphic small round blue cells in dense sclerosis. Spindle cells were SMA-, nuclear and cytoplasmic β-catenin-positive, STAT6- and TLE1-negative, and SS18 FISH-negative, supporting GPC. The round-cell component was CD20-positive but too scant for subclassification. Left partial maxillectomy showed a diffuse monomorphic round-cell infiltrate in sclerotic stroma. Cells were CD79a-, PAX5-, and BCL6-positive, with focal weak CD10 and Ki-67 ~25–45%, confirming B-cell lymphoma.
Discussion:The key decision was to evaluate the spindle-cell and round-cell components separately rather than force a single diagnosis. A targeted panel supported GPC and excluded major mimics. The round cell component was identified morphologically and confirmed by immunophenotypic findings as B-cell lymphoma; however, precise subclassification could not be established because of the dense sclerosis, and molecular testing was not performed.
Conclusion:The sinonasal mass contains two distinct neoplasms. The main lesson is to assess each component independently, use targeted immunohistochemistry, and correlate biopsy with resection. - Full text:2026090216520630897PJ Pathology Abstract 15.pdf
