Case 1 Diagnosis: Osteofibrous Dysplasia
Osteofibrous dysplasia is a rare bone tumor of the tubular bones, most commonly in the anterior cortex of the tibia, which is often referred to as an ossifying fibroma of the tubular bones. Thought to exist within a spectrum of benign to malignant with adamantinoma. Treatment is controversial but follow up radiographs and careful observation is paramount to asses for possible degeneration to adamantinoma.
Case 2 Diagnosis: Bone Infarcts in Systemic Lupus Erythematosus
Bone infarcts are seen in a multitude of conditions, predominantly at our institution from previous trauma, steroid use, and in the setting of a vasculitis. Infarcts associated with Lupus are thought to be in part secondary to steroid treatment but also secondary to the underlying vasculitis that afflicts multiple organ systems in these patients. The nonerosive subluxation, or Jacoud type arthropathy of the hand is classic for SLE, and helps in narrowing the differential of a bone infarct.
Case 3 Diagnosis: Osteoid Osteoma
Bony lesion of osteoid and immature bone that incites an adjacent reactive bony/inflammatory response secondary to prostoglandin release. Typically in younger patients (5-25 ) and with a classic clinical pattern of night time pain alleviated with aspirin. Classified as cortical, cancellous, and subperiosteal. This case presents the rarest type, a subperiosteal lesion. Current standard of care is radiofrequency ablation if possible or resection.
Case 4 Diagnosis: Paget Sarcoma
Comments: Paget disease is a fairly common disease of the older patient population classically manifest by cortical thickening, enlarged bone, and thickened, coarsened trabeculae. Multiple complications are well known including fracture, cranial nerve impingement, and malignant transformation. Most commonly this involves degenration to an osteosarcoma as in this case but may alternatively be a fibrosarcoma, malignant fibrous histiocytoma, or chondrosarcoma.
Case 5 Diagnosis: Ankylosing Spondylitis
Seronegative arthropathy that produces syndesmophytes (ossification of the annulus fibrosus) that start at the thoracolumbar junction and extend cranially and caudally, sacroilitis with eventual fusion, and enthesopathic change. In cases of marked disease and later in the time course dural ectasia may become manifest with associated cauda equina syndrome.
Case 6 Diagnosis: Scleroderma
Comments: Connective tissue disorder more prevalent in women than men that produces symptomatology generally in the second to third decade and continues to progress. Underlying pathology is a fibrosis that affects multiple organ systems. Classic findings include myositis of the proximal musculature that later precipitates fatty atrophy and large, conglomerate tumorlike or sheet like calcification of the soft tissue. It is frequently associated with other syndromes and produces an interstitial lung disease, preferentially at the lung bases, and esophageal dysmotility or a patulous esophagus.
Case 7 Diagnosis: Infectious Bursitis/Osteomyelitis
Comments: A true bursa such as the olecranon bursa is a synovial lined sac that can become inflammed from infectious and non infectious entities. In either situation, the underlying bone is susceptible to the same aggressive process. MRI is highly suggestive for infection when a marrow edema pattern is present in a diffuse pattern with adjacent soft tissue edema. Thick, enhancing soft tissue or bony lesions in the setting of possible infection are essentially diagnostic. The triceps destruction with avulsion is just a “collateral” injury.
Case 8 Diagnosis: Melorrheostosis
Comments: A benign bony proliferative process typically identified in early adulthood but sometimes becoming symptomatic only later in adult life when there is pain and limitation of joint movement secondary to bony encroachment. Additionally, there may be adjacent soft tissue inflammation as in this case which is precipitating an iliotibial band friction type syndrome. There is a typical candle wax cortical thickening and trabecular condensation in a sclerotomal (distribution of the skeleton supplied by a sensory nerve) distribution. In approximately one quarter of the cases, soft tissue masses with calcification are seen.
Case 9 Diagnosis: Lisfranc Ligament Disruption
Comments: High resolution MRI demonstrates a high grade partial disruption of the Lisfranc ligament in the first case and a complete disruption in the second case. The ligament acts as the keystone in support of the midfoot as it courses from the base of the second metatarsal to the medial cuneiform. Recent literature has helped substantiate that any offset is probably amenable to surgical fixation as malalignment will precipitate pain and early, profound arthrosis.
Case 10 Diagnosis: Hemangioma
Osseous hemangioma is a common vascular tumor most frequently encountered in the vertebral body of the lower thoracic or lumbar vertebrae. Imaging findings reflect prominent bony resorption of the majority of the osseous trabeculae with the remaining trabeculae demonstrating a thickened, coarsened architecture frequently referred to as “corduroy” or “polka dot." Often will be associated with focal areas of fatty signal (high T1, high T2, low IR) and typically show no uptake of radionuclide on bone scan but may demonstrate up to moderate uptake.