School ager with a rapidly enlarging soft tissue mass of the right chest and arm

CXR and CT of malignant peripheral nerve sheath tumor in neurofibromatosis type 1
CXR PA and lateral shows a right apical thoracic mass with associated rib thinning that had rapidly increased in size in a short interval. Axial CT without contrast of the chest better defined the right apical mass and demonstrated multiple serpiginous nodules in the soft tissues of the right anterior chest wall.

The diagnosis was degeneration of a plexiform neurofibroma into a malignant peripheral nerve sheath tumor in a patient with neurofibromatosis type 1.

Young adult treated for leukemia as a preschooler, now with new palpable sternal mass

CT of epithelioid sarcoma with pulmonary metastases
Axial CT without contrast of the chest with soft tissue (above) and lung (below) windows shows a heterogeneous mass contiguous with the rectus muscles and anterior to the lower sternum which appears to be eroding into the sternum along with multiple peripheral pulmonary soft tissue nodules.

The diagnosis was epithelioid sarcoma with pulmonary metastases.

Infant with torticollis and a right superior chest wall mass

CT and US of fibromatosis coli / torticollis tumor
Axial CT with contrast of the chest (above) shows asymmetry of the sternocleidomastoid muscles, right larger than left. Transverse US of the chest (middle) at the same level of the CT better shows the enlarged right sternocleidomastoid muscle. Sagittal US of the sternocleidomastoid muscles (bottom) shows the normal smooth contour of the left sternocleidomastoid muscle and the spindle shaped appearance of the right sternocleidomastoid muscle.

The diagnosis was fibromatosis coli.

Infant with severe eczema and an enlarging left chest wall mass over the last week and elevated white count

CT and MRI of osteomyelitis of the rib
Axial CT without contrast of the chest (above) shows bilateral axillary adenopathy and soft tissue swelling over the left lateral chest wall and associated rib destruction. Coronal T2 MRI of the chest (below left) shows a high signal intensity fluid collection between the skin and the ribs with surrounding edema. Axial T1 MRI with contrast of the chest (below right) shows extensive enhancement of the left ribs and surrounding muscle.

The diagnosis was cellulitis and a subcutaneous abscess resulting in osteomyelitis of the rib via direct extension. The abscess was drained operatively and grew staphlococcus.

School ager with right hip pain

Radiograph and CT of osteoid osteoma of the femur
AP radiograph of the pelvis shows a round lucent lesion in the right femoral neck. Coronal 2D reconstruction and axial CT without contrast of the pelvis shows the lesion to be centered in the cortex, to have a central calcification in a radiolucent nidus, and to be surrounded by reactive sclerosis. There is also a left hip effusion on the lower left CT image.

The diagnosis was osteoid osteoma of the femur.