Primary extramedullary plasmacytoma of the nasal cavity: a case report of a resource-limited setting

Introduction and importance: Extramedullary plasmacytoma (EMP) is an uncommon plasma cell neoplasm, representing approximately 3% of all plasma cell disorders, with a predilection for the upper aerodigestive tract. Lesions involving the nasal cavity and paranasal sinuses are exceedingly rare and may mimic other sinonasal malignancies, posing diagnostic challenges in resource-limited settings. Case presentation: A 59-year-old female presented with a gradually progressive right nasal obstruction associated with occasional epistaxis and nasal discharge. Examination revealed a greyish-white irregular mass occupying the right nasal cavity. Computed tomography demonstrated a 6.2 × 3.7 × 6.5 cm mildly enhancing lesion within the right ethmoidal sinus, extending into adjacent structures, suggestive of malignancy. Histopathology confirmed plasmacytic proliferation consistent with EMP. Immunohistochemistry for S100, recommended to exclude melanoma, could not be performed due to resource constraints. The patient underwent wide local excision with right total maxillectomy under general anesthesia. Postoperative recovery was uneventful, and she was discharged after 7 days with advice for prosthetic rehabilitation. Clinical discussion: EMP is a radiosensitive tumor managed with surgery, radiotherapy, or a combination of both. Differentiation from multiple myeloma and other plasma cell neoplasms requires clinical, radiological, and pathological correlation. Regular follow-up is crucial to monitor recurrence or progression to myeloma. Conclusion: Sinonasal EMP is a rare but treatable entity. Accurate diagnosis, complete excision, and consistent follow-up are essential for achieving favorable outcomes, particularly in resource-constrained environments.