Cervical spine tenosynovial giant cell tumor involving the atlantoaxial joint in a pediatric patient with medulloblastoma.

Tenosynovial giant cell tumor (TGCT) is a benign condition that arises from tendon sheaths, synovium, or bursae and is classified according to the site of involvement (intra-articular versus extra-articular) and pattern of growth (localized versus diffuse). The diffuse form tends to present as peri-articular masses and are locally aggressive. It usually presents as a mono-articular process affecting larger joints. Spinal involvement is extremely rare, particularly the cervical spine. In this case report, we present a pediatric case of spinal TGCT involving the C1-C2 joint which was incidentally detected in a 13-year-old girl undergoing surveillance for medulloblastoma recurrence. Although spinal TGCT is a benign condition, it remains a diagnostic challenge, which specific to our case can raise the concern for malignancy or metastasis. We also described a percutaneous biopsy approach using a spring-loaded blunt tip coaxial needle to avoid inadvertent vascular injury. The imaging features of spinal TGCT and biopsy approach for atlantoaxial lesion are discussed together with a comprehensive review of the literature.

Multifocal extra-adrenal myelolipomas with bilateral perirenal and retroperitoneal nodal involvement-Computed tomography features.

Extra-adrenal myelolipomas are exceedingly rare benign tumors composed of adipose and myeloid tissues, which have been reported to occur in various sites including the retroperitoneum, pelvis, and thorax. Myelolipomas are more commonly encountered in the adrenal glands. We illustrate a case of a 72-year-old woman with surgically proven bilateral perirenal and para-aortic lymph nodal myelolipomas detected incidentally by computed tomography. Extra-adrenal myelolipomas can be difficult to distinguish from other fat-containing lesions particularly liposarcomas, which are more commonly encountered in the retroperitoneum. This case highlights the unusual multifocal involvement of extra-adrenal myelolipomas and despite its rare occurrence, should be included in the differential diagnosis of retroperitoneal lipomatous lesions.