Squamous cell carcinoma arising from inverted Schneiderian papilloma: a case report

Background Sinonasal inverted papilloma or Schneiderian papilloma is a rare benign tumor of paranasal sinuses and nasal cavities. It can cause bone remodeling and has a significant malignant potential. Hence, it is very important to diagnose and treat the tumor at the earliest. Recurrence can occur even after surgical extensive resection. Case presentation This case report highlights a case of a 36-year-old male patient who presented with right-sided reduced vision, nasal blockage, headache, and occasional blood-tinged nasal discharge. CT scan of paranasal sinuses revealed chronic sinonasal polyposis with secondary fungal colonization. MRI of the brain with orbit and PNS was suspicious for aggressive neoplastic disease with encasement of the cavernous sinuses and involvement of orbital fissure. The patient was operated for extended functional endoscopic sinus surgery. Histopathology revealed moderately differentiated invasive squamous cell carcinoma associated with Schneiderian (inverted) papilloma. Post-operatively, the patient received radiation for 4 weeks. Post-operative check nasal endoscopy was done 3 and 6 months after completion of radiotherapy which showed no evidence of recurrent disease with good healing and mucosalization of all the sinuses. Conclusions Sinonasal inverted papilloma, though a benign tumor, may turn malignant. Diagnosis is based on radiological investigations (in order to know the extent of the disease) and biopsy (to check if it is benign or additional malignancy present). Staging of the tumor helps in outlining the treatment protocol in each case. Post-surgery radiotherapy is indicated in cases where there is malignancy or complete resection of the tumor cannot be achieved. Meticulous follow-up of the post-operative patients is vital to check for recurrence.