Macrophage-tropic variants of SIV are associated with specific AIDS-related lesions but are not essential for the development of AIDS.

The importance of macrophage infection for the development of acquired immune deficiency syndrome (AIDS) was investigated. Molecularly cloned simian immunodeficiency virus (SIV)mac239 replicates very poorly in cultured macrophages yet it causes AIDS in rhesus monkeys. Three of five rhesus monkeys that died with AIDS following SIVmac239 infection showed no disease manifestations directly associated with macrophage infection, such as encephalitis and granulomatous interstitial pneumonia. Simian immunodeficiency virus recovered from the peripheral blood of these three animals at or near the time of death replicated very poorly if at all in cultured macrophages, and tissues taken at autopsy showed little or no infection of macrophages by immunohistochemical staining. However two of the five rhesus monkeys that died with AIDS following SIVmac239 infection displayed a characteristic SIV-related meningoencephalitis and/or granulomatous pneumonia, lesions associated with macrophage infection. Simian immunodeficiency virus recovered from the peripheral blood of these two animals near the time of death replicated extremely well in cultured macrophages, indicating the emergency of macrophage-tropic variants in vivo. Furthermore tissues taken at autopsy from these two showed many infected macrophages by immunohistochemical staining. These results indicate that AIDS and death can occur without obvious involvement of macrophage infection. However the presence of macrophage-tropic viral strains appears to influence the disease course and disease manifestations.

A solitary testicular relapse of a rhabdomyosarcoma in an adult.

A case of recurrent rhabdomyosarcoma in an adult is reported. The primary disease at presentation was in the maxillary sinus with metastatic spread to regional lymph nodes. A complete response (CR) and a 14-month disease-free interval (DFI) were obtained with combination therapy. The sole site of relapse was an intratesticular mass. Management implications are discussed.

Hypocalcemia and an inappropriate endocrine response in osteoblastic metastatic breast cancer.

Hypercalcemia in association with skeletal metastases is common; hypocalcemia in this clinical setting is unexpected, though it has also been described, most commonly with primary lesions of the breast or prostate. In a subset of hypocalcemic patients with breast cancer, there is an inappropriate endocrinologic response as evidenced by a relative hypoparathyroidism and an elevation in the serum level of calcitonin. We have described a representative case and reviewed the literature.

Small cell carcinoma of the pleura.

Extrapulmonary small cell carcinoma is uncommon. Small cell carcinoma of pleural primary origin has not, based on a literature review of the past three decades, been reported. We have reported a case of small cell carcinoma of the pleura, discussed its management and significance, and briefly reviewed the pertinent literature.

Fusobacterium necrophorum septicemia without a primary focus.

We have presented a case of Fusobacterium necrophorum septicemia, an uncommon infection whose early course may be typified by vague diffuse symptoms or a seemingly benign upper respiratory tract inflammation mimicking acute viral syndromes or viral pharyngitis. The septicemia is most commonly, but not always preceded by an obvious oropharyngeal focus.