Mantle cell lymphoma with Homer-Wright rosettes

Mediastinal large B‐cell lymphoma with rosette formation mimicking thymoma and thymic carcinoid

“…It is not clear whether larger lymphoma cells form larger rosettes. The fibrillary centre of the rosettes consisted of complex cytoplasmic projections expressing CD45 and CD20, the same antigens as described on the tumour cells in other cases 2–5 . CD45 and CD20 are cell membrane proteins synthesized in the Golgi apparatus and transported onto the cell membrane.…”

“…On the other hand, their presence may represent a peculiar form of interaction between neoplastic lymphocytes or between tumour cells and the extracellular matrix that can lead to stronger intercellular adhesion 6 and thus, less locomotive/invasive or metastatic capability. The finding that the majority of reported cases have presented with low‐stage disease supports this idea 2–5 . Nevertheless, the prognostic significance of rosette formation in lymphoma warrants more case studies.…”

“…The fibrillary centre of the rosettes consisted of complex cytoplasmic projections expressing CD45 and CD20, the same antigens as described on the tumour cells in other cases. [2][3][4][5] CD45 and CD20 are cell membrane proteins synthesized in the Golgi apparatus and trans-ported onto the cell membrane. The accumulation of both proteins in the cytoplasmic processes may indicate a defect in protein transport in the tumour cells forming the rosettes.…”

“…have presented with low-stage disease supports this idea. [2][3][4][5] Nevertheless, the prognostic significance of rosette formation in lymphoma warrants more case studies.…”

Meningioma with rosettes: A rare morphologic pattern

“…Besides these tumors, rosettes rarely occur in lymphoma, endometrial stromal sarcoma and osteosarcoma . Here, we discuss a case of meningioma showing rosettes with collagenous cores.…”