HPV-Related Carcinoma with Adenoid Cystic-Like Features: Report of a Case with Early and Progressive Metastatic Disease

Introduction: HPV-related carcinoma with adenoid cystic-like features, also known as HPV-related multiphenotypic sinonasal carcinoma, is a newly described entity. The prognosis of this neoplasm is not well understood, but cases often demonstrate high-grade features and paradoxically indolent behavior. In a recent series, most cases had a solid growth pattern, but lacked regional or distant metastasis, with no tumor-related deaths.

Case Report: We present the case of a 65-year-old man referred with unilateral nasal congestion and epistaxis. Nasal endoscopy and imaging revealed an expansile mass filling the left nasal cavity. The patient underwent endoscopic-assisted medial maxillectomy, with complete resection and negative margins. Pathology revealed a highly cellular basaloid tumor consisting of solid nests with foci of cribriform architecture, with positivity for high-risk HPV, thus supporting the diagnosis of HPV-related carcinoma with adenoid cystic-like features. Immunohistochemical staining showed diffuse positivity for p16, p63, and CK7, with focal positivity for S100, calponin, actin, cKit, MYB, CEA, and SMA, consistent with prior reports. Postoperatively, the patient received 66.6 Gy adjuvant 3D proton therapy. Twenty-three months after surgical resection, he developed enlarging pulmonary nodules with biopsy features consistent with the primary sinonasal tumor. He was treated with three cycles of chemotherapy, with initial partial response but subsequent progression. He remains on palliative immunotherapy.

Conclusion: Here, we present a case of HPV-related carcinoma with adenoid cystic-like features with early and progressive distant metastasis. We aim to add to an understanding of the behavior of this entity. Although this neoplasm may typically be indolent, further classification of high risk features is necessary to identify rare aggressive cases.