Chondroid Tumors: Review of Salient Imaging Features and Update on the WHO Classification.

Chondrogenic tumors are typically well recognized on radiographs, but differentiation between benign and malignant cartilaginous lesions can be difficult both for the radiologist and for the pathologist. Diagnosis is based on a combination of clinical, radiological and histological findings. While treatment of benign lesions does not require surgery, the only curative treatment for chondrosarcoma is resection. This article (1) emphasizes the update of the WHO classification and its diagnostic and clinical effects; (2) describes the imaging features of the various types of cartilaginous tumors, highlighting findings that can help differentiate benign from malignant lesions; (3) presents differential diagnoses; and (4) provides pathologic correlation. We attempt to offer valuable clues in the approach to this vast entity.

Cytologic Features of Malignant Melanoma with Osteoclast-Like Giant Cells.

BACKGROUND: Malignant melanoma showing numerous osteoclast-like giant cells (OGCs) is an uncommon morphologic phenomenon, rarely mentioned in the cytologic literature. The few reported cases seem to have an aggressive clinical behavior. Although most findings support monocyte/macrophage differentiation, the exact nature of OGCs is not clear. CASE: A 57-year-old woman presented with an inguinal lymphadenopathy. Sixteen years before, cutaneous malignant melanoma of the lower limb had been excised. Needle aspiration revealed abundant neoplastic single cells as well as numerous multinucleated OGCs. Occasional neoplastic giant cells were also present. Nuclei of OGCs were monomorphic with oval morphology and were smaller than those of melanoma cells. The immunophenotype of OGCs (S100-, HMB45-, Melan-A-, SOX10-, Ki67-, CD163-, BRAF-, CD68+, MiTF+, p16+) was the expected for reactive OGCs of monocyte/macrophage origin. The tumor has shown an aggressive behavior with further metastases to the axillary lymph nodes and oral cavity. CONCLUSION: Numerous OGCs are a rare and relevant finding in malignant melanoma. Their presence should not induce confusion with other tumors rich in osteoclastic cells. Since a relevant number of OGCs in melanoma may mean a more aggressive behavior, and patients may benefit from specific treatments, their presence should be mentioned in the pathologic report.

Nosocomial lung infections in adult intensive care units.

Nosocomial respiratory tract infections are the leading type of nosocomial infections. Despite the development of new antibiotic therapies, they are associated with an increased morbidity and mortality. Patients with comorbidities are especially predisposed to acquire these infections, as are patients exposed to respiratory therapy. Aspiration of colonized secretions from the oropharynx is the main mechanism of infection development. Barrier techniques to reduce aspiration and antimicrobial agents to alter bacterial flora are important in preventing pneumonia episodes. The initial institution of an adequate antibiotic regimen is a determinant of outcome. Nosocomial pneumonias are often difficult to treat due to antibiotic-resistant bacteria. Antibiotic policies are crucial in avoiding a progression in antibiotic resistance.