Epithelioid sarcoma with heterotopic bone: a morphologic review of 4 cases.

Epithelioid sarcoma is an uncommon malignancy that usually arises in the superficial soft tissues of the extremities. Classically, epithelioid sarcoma grows as nodules of mild to moderately atypical epithelioid cells, frequently with central necrosis. The stroma is variably fibrous and may rarely contain heterotopic bone. The presence of bone within epithelioid sarcoma raises a variety of lesions in the differential diagnosis, including reactive processes as well as benign and malignant neoplasms.This morphological variant of epithelioid sarcoma and its associated diagnostic pitfalls has received little attention in the literature. The authors report herein 4 cases of epithelioid sarcoma with heterotopic bone and highlight the morphological characteristics of the bone and how such variants can be distinguished from other bone-forming lesions of the soft tissues.

Tenosynovial giant cell tumor of the posterior arch of C1.

Tenosynovial giant cell tumor, also called pigmented villonodular synovitis, is a disease typically of the joints and which uncommonly involves the spine. We present a case of a mass of the posterior C1 arch which eroded bone and did not arise from the facet joint. The imaging findings of spinal tenosynovial giant cell tumor will be reviewed as well as the imaging findings in this case, where tenosynovial giant cell tumor arose presumably within a small bursa. One's understanding of the imaging characteristics can lead to the correct diagnosis and avoid an unnecessary work-up.

Omental lipoblastoma.

A large intra-abdominal mass was discovered in a 6-month-old boy during a routine well-child examination. Imaging studies revealed a solid mass which appeared to arise from the left lobe of the liver, extending caudally and filling the entire pelvis. At the time of surgical excision, the mass was found to be unassociated with the liver, but was instead localized to the omentum. Histologic examination revealed adipocytes of varying stages of maturation arranged in a lobular architecture, consistent with a lipoblastoma. This unusual tumor is only the eighth reported omental lipoblastoma [J. Hicks, A. Dilley, D. Patel, J. Barrish, S. Zhu, M. Brandt, Lipoblastoma and lipoblastomatosis in infancy and childhood: histologic, ultrastructural, and cytogenetic features. Ultrastruct. Pathol. 25 (2001) 321-333; J. Harrer, G. Hammon, T. Wagner, M. Bolkenius, Lipoblastoma and lipoblastomatosis: a report of two cases and review of the literature. Eur. J. Pediatr. Surg. 11 (2001) 342-349; S. Weiss and J. Goldblum, Enzinger and Weiss's Soft Tissue Tumors, fourth ed., Mosby, St. Louis, MO, 2001, pp. 601-605, 670-686; S. Soin, S. Andronikou, R. Lisle, K. Platt, K. Lakhoo, Omental lipoblastoma in a child; diagnosis based in CT density measurements. J. Pediatr. Hematol. Oncol. 28(1) (2006) 57-58; A. Prando, S. Wallace, J.L. Marins, R.M. Pereira, E.R. de Oliveira, M. Alvarenga, Sonographic features of benign intraperitoneal lipomatous tumors in children-report of 4 cases. Pediatr. Radiol. 20(8) (1990) 571-574; C. Blank, E. Schoenmakers, P. Rogalla, E. Huys, A. Van Rijk, N. Drieschner, J. Bullerdiek, Intragenic breakpoint within RAD51L1 in a t(6;14)(p21.3;q24) of a pulmonary chondroid hamartoma. Cytogenet. Cell Genet. 95 (2001) 17-19; S. Ingraham, R. Lynch, S. Kathiresan, A. Buckler, A. Menon, hREC2, a RAD51-like gene, is disrupted by t(12;14)(q15;q24.1) in a uterine leiomyoma. Cancer Genet. Cytogenet. 115 (1999) 56-61]. Cytogenetics revealed a karyotype of 46,XY,t(8;14)(q13;q24). While lipoblastomas characteristically involve 8q, only one prior case has been reported with 14q24 as its fusion partner [M. He, K. Das, M. Blacksin, J. Benevenia, M. Hameed, A translocation involving the placental growth factor gene is identified in an epithelioid hemangioendothelioma. Cancer Genet. Cytogenet. 168 (2006) 150-154]. We report this unique case of an omental lipoblastoma with a focus on its unusual karyotype, as well as its differentiation from myxoid liposarcoma.

MRI of acute bone bruises: timing of the appearance of findings in a swine model.

OBJECTIVE: We developed an animal model of bone injury to determine the timing of the MR appearance of bone bruises and to follow these changes over time. MATERIALS AND METHODS: We performed serial MRI of 16 knees of eight swine with one nontraumatized knee as a control and 15 knees traumatized by direct patellar impact injuries using a force-calibrated device. All knees were imaged on a 1.5-T scanner using an 8-channel phased-array coil with T1-weighted, fat-saturated T2-weighted and STIR sequences. Scanning was performed at 1, 6, 12, and 30 hours after impact injury. Two radiologists independently reviewed each MR examination to identify MR signal intensity changes in the patellae and adjacent femoral condyles. RESULTS: In the 15 traumatized knees, bone bruises were noted in 93% of the patellae on T1-weighted images and in 87% of the patellae on fluid-sensitive MR images at 1 hour after injury and in 100% of the patellae at 6 hours. T1-weighted images were insensitive for detection of bone bruises in the femoral condyles. Bone bruises in the femoral condyles were seen on fluid-sensitive MR sequences as early as 1 hour after injury, with an increasing frequency over the 30-hour period. CONCLUSION: Bone bruises can be seen as soon as 1 hour after trauma but may not be seen until 30 hours after trauma. Fluid-sensitive (fat-saturated, T2-weighted, and STIR) MR sequences are more sensitive than T1-weighted images in the detection of bone bruises.

Colonic adenocarcinoma in a 13-year-old with cystic fibrosis.

The increase in longevity among patients with cystic fibrosis has brought to light comorbidities associated with the disease that are less acutely fatal than its pulmonary manifestations. Modern retrospective analysis has demonstrated an increased risk of gastrointestinal malignancy in patients with cystic fibrosis, with a marked elevation in malignancy rates among patients in their 20s and 30s. Here we report a case of colonic adenocarcinoma presenting as pneumaturia in a 13-year-old patient with cystic fibrosis.