[Joint tumors: rare but important differential diagnoses of malignant and benign tumors as well as pseudotumors in rheumatology]. / Gelenktumoren: Seltene, aber wichtige Differenzialdiagnosen von malignen und benignen Tumoren sowie Pseudotumoren in der Rheumatologie.

This review article elucidates the differential diagnostics of malignant and benign joint tumors, pseudotumors of the joints and the peri-implant tissue, which are rare but important entities in rheumatology and orthopedic rheumatology. The tissue of origin includes the synovium, peri-implant tissue, peri-articular fibrous tissue and peri-articular osseous tissue. Pseudotumors can be viewed as independent but heterogeneous entities. These are essentially manifested as tumor-like depositions of crystals, calcareous deposits, vascular malformations, ectasia of the synovia and joint capsule tissue and pseudocysts. Other causes for pseudotumors are focal destructive inflammation (e.g. induced by foreign bodies), high grade synovitis and focal fibrinoid necrosis (i.e. rheumatoid nodules). Methodologically, these diagnostics are based on conventional standard staining methods, immunohistochemical analyses of formalin-fixed and paraffin-embedded materials and on molecular diagnostic procedures. The latter are of great importance in cases of benign and malignant joint tumors. The most important immunohistochemical markers with respect to joint tumors are S100, SM-actin, CD68, CD34, STAT6, clusterin, Muc­4, beta-catenin and MDM2-FISH. The following markers are recommended for the differential diagnostics and typing of periarticular tumor metastases in the pathology of rheumatic diseases: AE1/AE3, CK8, p63, TTF­1, TGB, PSA, androgen receptor, GATA, CD56, chromogranin, CDX­2, SAT-B2, SALL4, estrogen and progesterone receptors, CD45LCA, CD30, CD79a and S100. Necrosis, inflammatory infiltrations and reparative inflammatory changes may complicate the histopathological classification. Therefore, a correlation with clinical, microbiological and radiological data in the sense of interdisciplinary synergistic diagnostics may be required.

[Unclear liver lesions in a 19-year-old woman with acute myeloid leukemia]. / Unklare Leberraumforderungen bei einer 19-jährigen Patientin mit akuter myeloischer Leukämie.

A 19-year old woman with acute myeloid leukemia presented with newly observed liver lesions during ongoing consolidation therapy. Due to unexplained cholestasis during induction, biliary duct drainage was performed. Microbiologic and histologic examinations revealed the presence of atypical mycobacteria, namely Mycobacterium abscessus. With an appropriate antiinfective regime which was continuously administered using a portable pump in the outpatient setting, further mycobacterial spread during simultaneous chemotherapy-associated neutropenia was prevented. Despite multiple bacterial resistance mechanisms, proper treatment of leukemia with curative intention could be ensured.

Ewing sarcoma dissemination and response to T-cell therapy in mice assessed by whole-body magnetic resonance imaging.

BACKGROUND: Novel treatment strategies in Ewing sarcoma include targeted cellular therapies. Preclinical in vivo models are needed that reflect their activity against systemic (micro)metastatic disease. METHODS: Whole-body magnetic resonance imaging (WB-MRI) was used to monitor the engraftment and dissemination of human Ewing sarcoma xenografts in mice. In this model, we evaluated the therapeutic efficacy of T cells redirected against the Ewing sarcoma-associated antigen GD2 by chimeric receptor engineering. RESULTS: Of 18 mice receiving intravenous injections of VH-64 Ewing sarcoma cells, all developed disseminated tumour growth detectable by WB-MRI. All mice had lung tumours, and the majority had additional manifestations in the bone, soft tissues, and/or kidney. Sequential scans revealed in vivo growth of tumours. Diffusion-weighted whole-body imaging with background signal suppression effectively visualised Ewing sarcoma growth in extrapulmonary sites. Animals receiving GD2-targeted T-cell therapy had lower numbers of pulmonary tumours than controls, and the median volume of soft tissue tumours at first detection was lower, with a tumour growth delay over time. CONCLUSION: Magnetic resonance imaging reliably visualises disseminated Ewing sarcoma growth in mice. GD2-retargeted T cells can noticeably delay tumour growth and reduce pulmonary Ewing sarcoma manifestations in this aggressive disease model.

[Indications for tissue biopsy. Diagnostic histopathology in rheumatological diseases]. / Biopsieindikationen. Histopathologische Diagnostik in der Rheumatologie.

The role of a standardized histopathological examination of tissue biopsies and of different tissue compartments (synovia, vascular tissue, bone) is discussed in order to stratify the therapy of different forms of arthritis and other rheumatological diseases. Furthermore the diagnostic steps for the histopathological diagnosis of metabolic osteopathic diseases are highlighted. The synovitis-score is described as a diagnostic device leading to the diagnosis of a low-grade synovitis, which is associated with degenerative and posttraumatic arthropathies, or of a high-grade synovitis which is associated with rheumatic diseases.

The ganglioside antigen G(D2) is surface-expressed in Ewing sarcoma and allows for MHC-independent immune targeting.

BACKGROUND: Novel treatment strategies are needed to cure disseminated Ewing sarcoma. Primitive neuroectodermal features and a mesenchymal stem cell origin are both compatible with aberrant expression of the ganglioside antigen G(D2) and led us to explore G(D2) immune targeting in this cancer. METHODS: We investigated G(D2) expression in Ewing sarcoma by immunofluorescence staining. We then assessed the antitumour activity of T cells expressing a chimeric antigen receptor specific for G(D2) against Ewing sarcoma in vitro and in vivo. RESULTS: Surface G(D2) was detected in 10 out of 10 Ewing sarcoma cell lines and 3 out of 3 primary cell cultures. Moreover, diagnostic biopsies from 12 of 14 patients had uniform G(D2) expression. T cells specifically modified to express the G(D2)-specific chimeric receptor 14. G2a-28ζ efficiently interacted with Ewing sarcoma cells, resulting in antigen-specific secretion of cytokines. Moreover, chimeric receptor gene-modified T cells from healthy donors and from a patient exerted potent, G(D2)-specific cytolytic responses to allogeneic and autologous Ewing sarcoma, including tumour cells grown as multicellular, anchorage-independent spheres. G(D2)-specific T cells further had activity against Ewing sarcoma xenografts. CONCLUSION: G(D2) surface expression is a characteristic of Ewing sarcomas and provides a suitable target antigen for immunotherapeutic strategies to eradicate micrometastatic cells and prevent relapse in high-risk disease.

Paraneoplastic neurological syndromes in patients with carcinoid.

BACKGROUND: Paraneoplastic neurological syndromes (PNS) are mainly associated with small-cell lung cancer, gynaecological tumours and lymphomas. Few studies report the association of neurological syndromes with a carcinoid, the majority being a serotonin-related myopathy. We report four patients with a PNS associated with carcinoid. PATIENTS AND RESULTS: The clinical syndromes were sensory neuropathy, limbic encephalitis, myelopathy and brain stem encephalitis. Two patients had antineuronal autoantibodies (one anti-Hu, one anti-Yo), one patient had antinuclear antibodies, and one patient had no autoantibodies. For two of the carcinoids, expression of HuD in the tumour could be demonstrated. CONCLUSION: This study demonstrates that carcinoids can also be associated with classical antineuronal antibody-associated PNS.