Atypical stromal cells, a pseudosarcomatous change in sinonasal polyp causing diagnostic dilemma - A case report and review of literature

Nasal polyposis is a commonly encountered non-neoplastic inflammatory disease of the nose and paranasal sinuses presenting with various clinical manifestations like nasal obstruction, rhinorrhea, headache, anosmia/hyposmia, etc. The two most common etiologies of nasal polyps includes allergy and infections. The incidence of nasal polyposis in the general population is 0.5 to 4%. The histological diagnosis of benign inflammatory polyps of the nasal cavity usually doesnot pose any diagnostic difficulties. However, certain unusual histological features can be observed rarely which might be a huge challenge to the pathologists as they can mimic sarcoma. We hereby present one of the unusual feature - atypical stromal cells in a nasal polyp which we came across during histopathological examination of an antrochoanal polyp from a 34 year old female who presented with bilateral nasal obstruction. Pathologists and clinicians must be well aware of this entity, though they are rare. A better understanding of this entity - atypical stromal cells in a benign inflammatory polyp can help in preventing an erroneous diagnosis of sarcoma, thereby preventing unnecessary treatment and anxiety to the patient.