Kaposi Sarcoma (KS) is an angio-proliferative mesenchymal neoplasm that typically affects the skin. In the setting of AIDS, it is usually disseminated, commonly involving noncutaneous sites like oral cavity, lymph nodes, pulmonary, and gastrointestinal systems. Musculoskeletal system involvement by KS is rare, and when encountered, it typically involves the axial skeleton (vertebrae, ribs, sternum, and pelvis) and/or maxillofacial bones. This report describes an unusual case of a 44-year old patient with HIV, who presented with a foot ulcer that fit the typical clinical features of osteomyelitis until MRI of the foot demonstrated atypical findings that challenged the original clinical diagnosis. This case highlights the role that advanced diagnostic imaging plays in the diagnosis of musculoskeletal Kaposi Sarcoma and serves as a reminder to radiologists to include Kaposi Sarcoma in the differential of multifocal osteolytic lesions in patients with HIV.

Candida parapsilosis has been considered an emerging pathogen with increasing incidence reported in the literature. As a normal commensal of human skin, it is likely that Candida species could gain access to soft tissues of the hand and wrist by direct inoculation, resulting in an infectious tenosynovitis. With the increased prevalence of intravenous drug use (IVDU), users are at increasing risk for musculoskeletal infections including soft tissue abscesses, cellulitis, tenosynovitis, and septic arthritis. Chronic tenosynovitis, with rice body formation in particular, is a comparatively rare musculoskeletal infection. Knowledge of this entity, the related pathogens, imaging findings, and the treatment plan is important not only to the treating clinician, but also to radiologists as the physiological and anatomic consequences can be detrimental to patient recovery.

Magnetic resonance arthrography is used to optimally image the detailed intraarticular anatomy of the joint space. A common iatrogenic complication of arthrography is the extra-articular injection of the gadolinium solution in the periarticular tissues; however, a less common complication involves the abnormal concentration of gadolinium within the prepared injectate. The following describes the inadvertent injection of a hyper-concentrated intraarticular solution of gadolinium and the subsequent appearance that resulted in the post-procedure magnetic resonance imaging examination. In addition, an in-vitro experiment was performed to determine the exact etiology of the abnormal magnetic resonance imaging findings that resulted in this case. The subsequent discussion revisits the signal intensity of gadolinium at extreme concentration ranges and proposes modifications of procedure protocol to mitigate the chance of a repeat event.

No abstract