CONCLUSIONS: Inflammatory pseudotumours in the maxillary sinus may present as malignant tumours and manifest locally aggressive features characteristic of such tumours. Despite their locally destructive features, they pursue a benign course after local excision. OBJECTIVE: Inflammatory pseudotumour (plasma cell granuloma) is an uncommon non-neoplastic lesion comprising a proliferation of spindle myofibroblasts and chronic inflammatory cells. Despite its benign histopathological nature, it may exhibit aggressive behaviour that is yet to be characterized in the head and neck area. MATERIAL AND METHODS: We present the cases of two adult patients with inflammatory pseudotumour arising from the maxillary sinus. Immunohistochemistry and polymerase chain reaction for immunoglobulin from tissue sections were performed to confirm the polyclonality of the infiltrating plasma cells. RESULTS: CT and MRI disclosed expansive soft masses eroding surrounding soft and bony tissues. Histopathologically, the lesions were unencapsulated and composed of numerous plasma cells, histiocytes and spindle cells with minimal nuclear pleomorphism.
CONCLUSIONS: Inflammatory pseudotumours in the maxillary sinus may present as malignant tumours and manifest locally aggressive features characteristic of such tumours. Despite their locally destructive features, they pursue a benign course after local excision. OBJECTIVE: Inflammatory pseudotumour (plasma cell granuloma) is an uncommon non-neoplastic lesion comprising a proliferation of spindle myofibroblasts and chronic inflammatory cells. Despite its benign histopathological nature, it may exhibit aggressive behaviour that is yet to be characterized in the head and neck area. MATERIAL AND METHODS: We present the cases of two adult patients with inflammatory pseudotumour arising from the maxillary sinus. Immunohistochemistry and polymerase chain reaction for immunoglobulin from tissue sections were performed to confirm the polyclonality of the infiltrating plasma cells. RESULTS: CT and MRI disclosed expansive soft masses eroding surrounding soft and bony tissues. Histopathologically, the lesions were unencapsulated and composed of numerous plasma cells, histiocytes and spindle cells with minimal nuclear pleomorphism.