E1095. Pseudolesions of the Hand and Wrist: Uncover the Imposters with Intelligent Imaging
  1. Adam Graeber; Wilford Hall Ambulatory Medical Center
  2. Nathan Cecava; Wilford Hall Ambulatory Medical Center
  3. Douglas Byerly; Wilford Hall Ambulatory Medical Center
The hand and wrist are an area of complex musculoskeletal anatomy that includes multiple tissue elements to include bone, ligaments, tendons, muscles, synovium, and neurovascular structures. Given this abundance of varying tissue types there are numerous true and pseudolesions that occur and are a common cause for presentation accounting for 6% of bone tumors and 15% of soft tissue tumors. Physical exam is often non-specific and thus imaging becomes crucial in work-up and management. Radiologist-directed imaging across various modalities is important for efficient lesion characterization and directing disposition. Common examples of pseudolesions of the hand/wrist include anomalous muscles, crystalline and inflammatory arthropathies, intersection syndrome, synovial/tenosynovial chondromatosis or osteochondromatosis, ganglion cyst (to include periosteal, intraneural or intratendinous), bizarre parosteal osteochondromatous proliferation (BPOP), bone graft harvest site, generalized tenosynovitis, pseudoaneurysm, infection (septic arthritis, osteomyelitis, abscess or tenosynovitis), accessory ossicles (carpal boss) and sequela of trauma.

Educational Goals / Teaching Points
Introduce essential anatomy to provide a backbone for further discussion of pathology. Review the pathogenesis of the pseudolesions of the hand/wrist of the various aforementioned entities. Provide case examples of pseudolesions and discuss the various imaging findings across multiple modalities to provide a complete set of findings related to the various entities. Establish important clinical factors which can aid in clinching the specific diagnosis in concert with the imaging findings. Finally, provide the radiologist an imaging checklist for identification of psuedolesions so the patient can be spared unnecessary biopsy.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Clearly demonstrate the specific findings associated with the causes of pseudolesions of the hand/wrist. Demonstrate the various findings using radiography, ultrasound, computed tomography (to include dual-energy CT in the case of crystalline arthropathies), and magnetic resonance imaging findings to include the use of specialized sequences to increase the specificity of diagnosis. Discuss common imaging pitfalls to limit misdiagnosis, as well as unnecessary work-up, tissue sampling or surgical excision.

Masses of the hand and wrist are a common cause for presentation and distinguishing between true lesions from pseudolesions and can be challenging for the clinician as physical exam is often non-specific. Anomalous muscles, crystalline arthropathies, intersection syndrome, tenosynovitis, ganglion cysts, synovial chondromatosis, localized tenosynovial giant cell tumor, infection and sequela of trauma can all present as focal lesions on clinical exam and in most instances, imaging will be needed to characterize the mass. Knowledge of these entities as well as their various imaging appearances are critical to aid our referring clinicians and to spare the patient unnecessary invasive procedures such as biopsy or surgical excision.