First TP53-Mutant Low-Grade Papillary Schneiderian Carcinoma Documented Without DEK::AFF2 Fusion
A case report of sinonasal low-grade papillary Schneiderian carcinoma identified a TP53 R175H mutation by targeted DNA sequencing in the absence of the canonical DEK::AFF2 fusion. The finding demonstrates genetic heterogeneity within this rare entity and emphasizes the need for comprehensive molecular workup combining sequencing and FISH for accurate diagnosis.
The original study
Low-grade papillary Schneiderian carcinoma with TP53 mutation: a case report and review of the literature.
- Authors
- Yuzawa S, Michizuka T, Kakisaka R, Ono Y, Hayashi M, Takahara M, et al.
- Journal
- Diagnostic pathology
- Type
- Review, Case Reports, Journal Article
- PMID
- 37041626
Original abstract
BACKGROUND: Low-grade papillary Schneiderian carcinoma (LGPSC) is a relatively new entity of the sinonasal tract and is characterized by a bland morphology simulating sinonasal papilloma, invasive growth pattern with pushing borders, and aggressive clinical behavior with multiple recurrences and metastatic potential. Recently, DEK::AFF2 fusions were identified in LGPSC. However, some LPGSCs lack DEK::AFF2 fusion, and the molecular features of these tumors have not been clarified. CASE PRESENTATION: A 69-year-old man presented with a discharge of pus from his left cheek. Computed tomography revealed a mass involving the left maxillary sinus, ethmoid sinus, and nasal cavity with the destruction of the orbital wall. The biopsy specimens showed that the tumor had a predominantly exophytic, papillary growth and did not have an apparent stromal invasion. The tumor was composed of multilayered epithelium that showed bland morphology with a round to polygonal shape, abundant eosinophilic cytoplasm, and uniform nuclei. Dense neutrophilic infiltrates were focally present. Immunohistochemically, CK5/6 was strongly and diffusely positive, and p16 was negative. p63 was mainly positive in the basal layer, and EMA was predominantly expressed in the outermost cell layer. DNA-based targeted sequencing showed TP53 R175H mutation, whereas neither EGFR nor KRAS mutation was identified. Reverse transcription polymerase chain reaction and fluorescence in situ hybridization revealed no DEK::AFF2 fusion. CONCLUSIONS: We describe the first case of TP53-mutant LGPSC and review the literature. LGPSC is a genetically heterogeneous entity, and the recognition of this rare entity and comprehensive assessment of clinicopathological and molecular findings are crucial for the correct pathological diagnosis and clinical management.