Diagnosis of giant cell-rich bone tumors on core needle biopsy: A practical approach.

BACKGROUND: The differential diagnosis of giant cell-rich bone tumors comprises a broad spectrum of lesions with prominent reactive osteoclast-like and/or neoplastic giant cells, with substantial differences in biologic behavior and clinical management. Evaluation of giant cell-rich bone tumors on small biopsies can be challenging especially in specimens with limited representative material. An accurate diagnosis requires a high level of skill on the part of both radiologist and pathologist as correlation with clinical and radiologic characteristics is critical. The objective of the study was to assess the utility of touch preparations (TP), immunohistochemistry (IHC) for mutation-specific markers H3G34W and H3K36M, and fluorescence in situ hybridization (FISH) for USP6 rearrangements and MDM2 amplification in the diagnostic workup of core needle biopsy specimens. METHODS: A total of 27 core needle biopsies with TPs from patients with primary giant cell-rich bone tumors (16 giant cell tumors of bone (GCTBs) (including 3 with lung metastasis), 3 chondroblastomas (CBs), 4 primary aneurysmal bone cysts (ABCs), 2 non-ossifying fibromas (NOFs), 1 low grade osteosarcoma (OS), and 1 conventional OS with tumor giant cells were analyzed with IHC for H3G34W and H3K36M and in select cases FISH for USP6 rearrangements and MDM2 amplification. RESULTS: In all cases the core biopsies were sufficient for histologic examination and diagnostic workup. 16 of 16 GCTBs were positive for H3G34W and negative for H3K36M, and 3 of 3 CBs were positive for H3K36M and negative for H3G34W. All other cases were negative for H3G34W and H3K36M. 4 of 4 primary ABCs showed rearrangement of USP6 by FISH and the low grade OS showed amplification of MDM2 by FISH. CONCLUSIONS: On-site adequacy assessment of TPs proved to be an accurate, simple, and fast method for obtaining sufficient material for complete diagnostic workup. The application of IHC for H3G34W and H3K36M and FISH for detection of rearrangements of USP6 and amplification of MDM2 can improve the diagnostic accuracy in core needle biopsy specimens.

Imaging of rhinosinusitis and its complications: plain film, CT, and MRI.

Conventional plain-film radiography may be used as a screening method for various pathological conditions of the sinonasal cavities. However, CT scanning remains the study of choice for the imaging evaluation of acute and chronic inflammatory diseases of sinonasal cavities. MRI is superior to CT in differentiating inflammatory conditions from neoplastic processes. The most common complications of rhinosinusitis in children occur in the orbit. The information obtained from the CT scan and MRI, together with clinical findings, may be the best guidelines for clinical management and the mode of treatment. Although intracranial complications of sinusitis are relatively rare, prompt recognition of these disease states is important to prevent permanent neurological deficit or fatality. It is prudent to obtain MRI of the sinuses, orbits, and brain whenever extensive or multiple complications of sinusitis are suspected, in addition to CT scanning. Chronic rhinosinusitis is a clinical diagnosis, confirmed and staged with the CT scan of sinonasal cavities. Chronic inflammatory disease is often associated with mucosal thickening and sclerosis of the bone, particularly within the sinuses. Chronic extramucosal fungal sinusitis develops as a saprophytic growth in retained secretions in a sinus cavity. The imaging manifestations of chronic mycotic rhinosinusitis may be nonspecific or highly suggestive of the presence of fungal infection. The presence of diffuse increased attenuation within the paranasal sinuses and nasal cavity should be considered as chronic allergic hypersensitivity aspergillosis (chronic noninvasive aspergillosis) or chronic hyperplastic sinusitis and polyposis associated with desiccated, retained mucosal secretions. The MRI characteristics of fungal sinusitis depend on the stage of the disease.