A Case of Rapidly Progressive DEK::AFF2 Fusion-Associated Papillary Squamous Cell Carcinoma in Pregnancy.

BACKGROUND: DEK::AFF2 fusion-associated carcinoma is a recently recognized subtype of nonkeratinizing squamous cell carcinoma that may be underdiagnosed due to overlap with benign sinonasal lesions and reliance on molecular confirmation. METHODS: A 39-year-old woman at 29 weeks' gestation presented with progressive swelling of the left nasal ala. She had a prior resection of DEK::AFF2 carcinoma and was lost to follow-up. MRI demonstrated a 2.9-cm recurrent mass, and incisional biopsy confirmed recurrence. RESULTS: Given the historically described low- to intermediate-grade behavior of this tumor, the multidisciplinary tumor board recommended deferring surgery until after term delivery. However, the lesion demonstrated rapid progression over 4 weeks, enlarging to 4.5 cm. Following repeat tumor board discussion, labor was induced at 36 weeks, followed by medial maxillectomy, neck dissection, and free flap reconstruction. Final pathology revealed pT4aN1 disease. The patient completed adjuvant radiation therapy and remains disease-free at 8 months. CONCLUSIONS: This case highlights potential aggressive behavior in DEK::AFF2 carcinoma and possible pregnancy-associated tumor acceleration.