Spinal subarachnoid hematoma resulting from lumbar myelography.

We describe a rare complication of myelography. A subarachnoid filling defect was apparent on the postmyelographic CT but not on conventional myelography. MR imaging performed later showed a spinal subarachnoid hematoma (SSAH), extending from L3 to L5. Lumbar puncture may rarely be a cause for SSAH and is more common in patients with coagulopathy. Significant back pain, paresis, radiculopathy, and even altered consciousness or meningeal signs may herald an SSAH.

Giant cell reparative granuloma of the petrous temporal bone: a case report and literature review.

Giant cell reparative granuloma (GCRG) is an unusual, benign bone lesion that most commonly affects the maxilla and mandible; skull involvement is rare. The etiology is uncertain but may be related to trauma. GCRG is difficult to distinguish from giant cell tumor of the bone and has a lower recurrence rate. Thirteen reports of temporal bone GCRG in 11 patients have been reported. One report of a petrous GCRG in a 3-year-old girl has been identified. A 38-year-old male presented with a 2-year history of fullness in his left ear, ipsilateral hearing loss, and intermittent cacosmia. Computed tomography and magnetic resonance imaging revealed a large left-sided anterior temporal extradural mass. The patient underwent a left frontotemporal craniotomy and resection of a left temporal fossa tumor that involved the petrous and squamous parts of the temporal bone. The patient's post-operative course was uneventful, except for increased hearing loss secondary to opening of the epitympanum. Follow-up at one month revealed no other problems. Histopathology of the specimen was consistent with a giant cell reparative granuloma.

Neoplastic transformation and DNA damage of mouse mammary epithelial cells by N-methyl-N'-nitrosourea in organ culture.

An appropriate in vitro system was used to study the effect of a direct-acting carcinogen on the transformation of mammary epithelial cells in the organ culture of the whole mammary gland in vitro. Studies were done to determine the ability of N-methyl-N'-nitrosourea (MNU) to transform the mammary cells in organ culture. Mouse mammary glands were treated with single or multiple doses of MNU during various periods of the culture. To assay for neoplastic transformation potential of MNU on mammary cells, mammary glands were dissociated and the cells were injected into the parenchyma-free inguinal mammary fat pad of syngeneic virgin female host mice. Palpable tumors were observed in injected glands of 23% of the mice after 3-4 months and an additional 31% showed serially transplantable hyperplastic alveolar nodules (HANs). Histopathologic examination of the tissues showed that the tumors were mammary adenocarcinoma. All tumors and hyperplasias were secondarily transplanted into syngeneic animals, resulting in tumors and hyperplasias of similar histopathology. In addition, DNA damage of the epithelial cells in organ culture caused by MNU was also measurable using the new nick translation assay. The most extensive DNA damage occurred when the glands were treated on day 4 and day 5 of the mammogenic culture period. These results demonstrate that the mouse mammary epithelial cells are susceptible to the carcinogenic action of the direct-acting carcinogen MNU and that the whole mammary gland-culture system offers an appropriate in vitro model for studying the mechanism of carcinogenesis induced by MNU.