A rare case of maxillary sinus and buccal space involvement of extramedullary plasmocytoma: Cross-sectional imaging findings and review of the literature.

Extramedullary plasmacytoma (EMP) belongs to the group of plasma cell neoplasms, which include following entities: multiple myeloma (MM), lymphoplasmacytic lymphoma, solitary plasmacytoma of the bone (SBP) and EMP. Localization in the maxillary sinus with simultaneous involvement of the buccal cavity is rare. Misdiagnosis may lead to inappropriate or delayed management. X-ray, computed tomography (CT) scan, magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) scan provide useful information for diagnosis. Many CT and MRI features are not specific and it is important to find specific imaging characteristics for making differential diagnosis. Our case has shown how, in the context of advanced MRI techniques, DWI is decisive in achieving the correct diagnosis of EMP The peculiarity of this case, in addition to showing the possibility, although rare, of a simultaneous involvement of EMP of the buccal cavity and of the ipsilateral maxillary sinus, presents the behavior of the EMP in various imaging methods, highlighting how diffusion-weighted imaging (DWI) played an important role to suggest the correct diagnosis and differentiating it from squamous cell carcinoma (SCC) and non-Hodgkin lymphoma (NHL).

Primary large B-cell lymphoma involving the cerebellopontine angle mimic acoustic schwannoma: Role of MR Spectroscopy in differential diagnosis. A case report.

Primary central nervous system (CNS) lymphoma is a very rare aggressive non-Hodgkin disease that originates in CNS (brain, leptomeninges, spinal cord, or eyes). It seems to have increased over the last two decades in both immunocompromised and immunocompetent patients. Primary large B-cell lymphoma involving the cerebellopontine angle (CPA) is extremely rare: only 15 cases of large B-cell lymphoma of the CPA have been reported worldwide; based on our knowledge, no cases studied with MR Spectroscopy. Primary large B-cell lymphoma of the CPA must be differentiated from other cerebellopontine angle diseases, such as acoustic neuroma and meningioma. An early and accurate diagnosis of this neoplasm is necessary for the best management because it is a radiosensitive and chemosensitive tumor. Herein, we report a rare case of B-cell lymphoma involving the left CPA in a 65-year-old man who presented with 3 months of hearing loss on the left, illustrated by MR and TC imaging, highlighting how the MR Spectroscopy, thanks to their greater specificity, is decisive in achieving the correct diagnosis of primary lymphoma and differentiating it from acoustic schwannoma or meningioma. Therefore, in the suspicion of a malignant heteroplastic lesion of the CPA, we suggest including Spectroscopy in the MR study protocol.