Schwannoma with monoclonal plasma cell infiltration

Collision tumor between a spinal schwannoma and chronic lymphocytic leukemia/small lymphocytic lymphoma: case report and review of the literature

A collision tumor is one where two neoplasms of differing type occur at the same anatomical site. We present a patient suffering from non Hodgkin small cell lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL) and complaining intense lumbar back pain refractory to medical treatment. Lumbosacral MRI showed an intradural extramedullary lesion in the left L2-L3 foramen with extracanalar development and compression of psoas muscle. CT showed intralesional calcification. The patient underwent resection of the lesion through a paraspinal posterolateral approach (Wiltse approach). The histology was of schwannoma with intralesional calcifications and lymphocitic infiltrates compatible with B-lineage SLL/CLL. After the operation the patient suffer from left psoas muscle motor weakness (3/5 MRC). Because of hematological disease progression, she underwent 6 cycles of chemioterapy (Fludarabine, Cyclophosphamide, Rituximab). At a six-month follow-up no recurrence or residual tumor upon lumbosacral MR imaging was detectable and the left thigh flexion returned normal. To our knowledge, this is the first described case in the literature of collision tumor between a solitary spinal Schwannoma and SLL/CLL.

Combined Schwannoma and Kappa-Restricted Plasma Cell Neoplasm: A Case Report and Review of the Literature

The patient is a 78-year-old woman with a popliteal soft tissue mass that was tender to palpation with shooting pain on physical examination. A schwannoma was seen on biopsy with subsequent excision demonstrating a concomitant kappa-restricted plasma cell neoplasm. Follow-up did not show evidence of a systemic plasma cell neoplasm. MRI studies showed no evidence of focal lesions, although PET-CT revealed presence of multiple lytic lesions. The patient is currently being monitored every six months. This case is the first kappa-restricted plasma cell neoplasm reported in association with a schwannoma and the first reported in the extremities.

Retroperitoneal schwannoma with monoclonal plasma cell infiltration: an exceptionally rare collision tumor?

Collision tumors within the retroperitoneum are rare. We present the case of a 54-year-old man with an incidental finding of a well-defined iliopsoas mass. He underwent marginal resection via an anterior superior ilio-inguinal approach. Histological examination revealed typical features of a schwannoma surrounded by a notable plasma cell infiltrate. On immunohistochemistry stains, the spindled cells displayed diffuse, strong nuclear and cytoplasmic positivity for S100, whereas epithelial membrane antigen, glial fibrillary acidic protein, and neurofilament stains were uniformly negative. The plasma cell infiltrate was diffusely positive for CD 138, with a majority of them demonstrating positive staining for lambda light chain and negative for kappa light chain. Hematological review found no evidence of marrow plasmacytosis and multiple myeloma was ruled out. At 12 month follow-up, the patient remains free of any recurrence. To our knowledge this is the second case of a schwannoma coexisting with a monoclonal plasma cell infiltrate and the first in the retroperitoneum.