2026 Poster Presentations
P298: CASE REPORT OF SINONASAL RENAL CELL-LIKE ADENOCARCINOMA
Vaishnavi L Rao, MD; Jessica Eaton, MD; Kobina Mensah Brown, MD, MS; Rumeal Whaley, MD; Janalee Stokken, MD; Michael J Link; Mayo Clinic
Sinonasal renal cell-like adenocarcinoma is a very rare neoplasm with the literature consisting of case reports and small case series. It is considered a subtype of non-intestinal-type sinonasal adenocarcinoma. Here, we present the case of a 68-year-old male with sinonasal renal cell-like adenocarcinoma. The patient has a history remarkable for peripheral T-cell lymphoma diagnosed 20 years prior status post chemotherapy and bone marrow transplant and subsequent diagnosis of myelodysplastic syndrome. He was incidentally found to have a left sinonasal lesion on CT imaging. MRI and CT (Figures 1 and 2) demonstrated a 2.5 x 1.3 x 2.4 cm enhancing lesion within the superior aspect of the left nasal cavity and the left anterior ethmoid sinus, eroding the cribriform plate. Rigid nasal endoscopy (Figure 3) confirmed a left olfactory cleft mass which was biopsied in the operating room due to its vascular appearance. The mass was noted to be involving the middle turbinate and skull base. The patient subsequently underwent a bifrontal craniotomy and endoscopic assisted craniofacial resection of the anterior skull base lesion with autologous fascia lata reconstruction of the defect. On histology, the neoplasm was remarkable for glandular proliferations composed entirely of cells with clear cytoplasm (Figure 4A). Papillary growth was scattered throughout the neoplasm (Figure 4B). The tubules were involved by a rich fibrovascular network, however hemorrhage was not a prominent feature. The neoplastic cells gave positive reactions with antibodies directed against carbonic anhydrase IX (Figure 4C), keratin 7, and SOX10. Negative reactions were observed with antibodies directed against PAX8 and S100 protein. Left cribriform dura was involved by carcinoma; all margins obtained were negative. Treatment of sinonasal renal cell like adenocarcinoma based on prior published cases typically involves surgical excision with or without adjuvant radiation therapy, with low recurrence rates reported. Given that we were able to obtain a gross total resection with negative margins, for this patient we plan to withhold adjuvant therapy and follow the patient with serial MRI scans at 6-month intervals for the next 5 years. Our case adds to the small but growing literature on this very rare diagnosis.
Figure 1: MRI
Figure 2: CT
Figure 3: Rigid nasal endoscopy of the lesion
Figure 4: Histology of sinonasal renal cell-like adenocarcinoma