Giant cell tumor with secondary aneurysmal bone cyst: a unique presentation with an ossified extraosseous soft tissue mass.

The authors describe a case of giant cell tumor (GCT) with secondary aneurysmal bone cyst (ABC) in a 44-year-old man with chronic, intermittent knee pain. A unique feature is the presentation of GCT with an ossified extraosseous soft tissue mass. Radiograph demonstrates a multiloculated lytic lesion in the distal meta-epiphyseal region of the femur with an adjacent extraosseous soft tissue mass. The soft tissue mass was partially ossified along its margin and internal septa. MRI demonstrates a multiloculated lesion in the distal femur with multiple fluid-fluid levels and cortical penetration of the lesion. Both the intraosseous lesion and extraosseous soft tissue mass have similar MR signal characteristics. At surgery, the intraosseous component was found to be contiguous with the extraosseous soft tissue mass through a cortical perforation. To the best of our knowledge, this is the first case report of GCT with aneurysmal bone cyst initially presenting with an extraosseous soft tissue mass.

CT evaluation of airway foreign bodies in children: emphasis on the delayed diagnosis and differentiation from airway mucus plugs.

PURPOSE: To review clinical and CT findings of airway foreign bodies (FBs) among children, with an emphasis on delayed diagnosis and differentiation from mucus plugs (MPs). METHODS: The CT findings and medical records of 27 patients (M:F = 17:10; mean age, 18.2 months) confirmed for FB (n = 20) and MP (n = 7) were reviewed. These findings were correlated with the bronchoscopic results and clinical outcomes. RESULTS: CT revealed air-trapping (70 %), atelectasis (35 %), pneumonia (25 %), and pneumomediastinum (5 %). Three patients with FB in the carina did not show air-trapping. The densities of the FBs ranged from 17 to 123 Hounsfield units (HU) (n = 17). Eight out of 20 patients (33 %) had a delayed diagnosis of FB. The CT of eight patients revealed air-trapping (n = 2), air-trapping with pneumonia or atelectasis (n = 3), and atelectasis only (n = 1). The airway MPs had a low density (0-5 HU) and were associated with atelectasis (29 %), atelectasis with pneumonia (43 %), and pneumonia (14 %). CONCLUSION: Air-trapping of the ipsilateral lung may not be a reliable finding among patients with an FB located in the carina and with a small-calibered FB. The absence of air-trapping, the difference in the HU, and the shape of the endobronchial lesion are helpful findings in the differential diagnosis of an MP.

Emphasis on the MR imaging findings of brown tumor: a report of five cases.

OBJECTIVE: Brown tumors are focal reactive osteolytic lesions that are encountered in patients with primary or secondary hyperparathyroidism, and these tumors have nonspecific magnetic resonance (MR) imaging findings. However, there are only a few reports on MR imaging of brown tumors. The purpose of this study is to describe the spectrum of MR imaging findings of brown tumors. MATERIALS AND METHODS: The MR imaging features of five patients with clinical and pathological evidence of brown tumor were retrospectively reviewed by two radiologists. The patients had primary hyperparathyroidism, which was confirmed as parathyroid adenoma (n = 2) and parathyroid carcinoma (n = 3). The MR images were evaluated for the presence of solid or cystic portions, the signal intensity of the lesions, the contrast enhancement pattern and the presence of cortex destruction and fluid-fluid levels. RESULTS: Twelve bone lesions were detected on the MR images of five patients; three lesions in two patients, four lesions in one patient, and one lesion in two patients. The tumor was solid in three lesions, mixed solid and cystic in four, and cystic in five. All the solid lesions were accompanied by mixed lesions. Discontinuity of the cortex and adjacent soft-tissue enhancement were seen in all the solid lesions. Fluid-fluid levels were seen in two cases within the cystic component of the mixed lesions and cystic lesions. CONCLUSIONS: The five patients with brown tumor demonstrated a wide spectrum of MR imaging findings. There are few lesions that are osteolytic on the radiographs and that show a short T2 on MR imaging, such as brown tumor. Multiple cystic or mixed lesions are the expected findings of brown tumors.

Metastatic gastric linitis plastica from bladder cancer mimicking a primary gastric carcinoma: a case report.

Primary gastric carcinoma is the most common cause of linitis plastica. Less frequently, metastatic gastric cancer from the breast, omental metastases and non-Hodgkin lymphoma involving the stomach have been reported to show similar radiographic findings as for linitis plastica. A metastatic gastric cancer from bladder cancer is extremely rare. We present an unusual case, the first to our knowledge, of gastric linitis plastica that resulted from a metastatic urothelial carcinoma of the bladder.