Introduction:
Extramedullary plasmacytoma is a rare entity which belongs to non-Hodgkin lymphoma category. Head and neck region is the most common site of manifestation, of which sinonasal area is of predominance which oftentimes remains undiagnosed.

Aim:
To illustrate unusual presentation of nasal mass and its management.

Case study:
Herein, we are reporting a case of sinonasal plasmacytoma in an elderly man who presented with a four month history of unilateral nasal blockage. Rigid nasoendoscopy revealed benign looking polypoidal mass occupying entire right nasal cavity with no evidence of any polypoidal mass seen over the left nostril. Computer tomography revealed homogenous soft tissue mass over right nasal cavity with minimal mucosal thickening in bilateral maxillary, ethmoid, sphenoid and left frontal sinus.

Results and discussion:
Patient underwent endoscopic clearance of right nasal mass under general anaesthesia. Nasal mass was removed with the aid of microdebrider and Blakesley forcep without difficulty. Intra- and postoperative were unremarkable. Histopathological examination of the nasal mass along with immunohistochemical study was suggestive of nasal plasmacytoma. In addition, systematic workup for multiple myeloma was negative. Subsequent follow-up revealed no evidence or recurrence and patient has been asymptomatic till date.

Conclusions:
Transnasal endoscopic surgical excision is an ideal treatment for small and localised extramedullary sinonasal plasmacytoma. Albeit rare, extramedullary sinonasal plasmacytoma should be considered as a differential diagnosis of sinonasal mass as this entity has tendency to develop into multiple myeloma as well as the different mode of management of this rare entity differs.