A case of infected schwannoma mimicking malignant tumor.

BACKGROUND: Infected schwannoma has been reported, this being one of the four cases published in the literature. Infected schwannoma has proven to be a tough diagnostic challenge to the treating tumor surgeon, mimicking infectious entities and most essentially, a malignant tumor. CASE PRESENTATION: The authors report the case of a 64-year-old male with a soft tissue mass in his right gluteal area that presented initially with right leg pain, then later with signs of inflammation on the tumor area. Magnetic resonance imaging (MRI), computed tomography (CT), and thallium-201 scintigraphy studies confirm the presence of soft tissue mass which had continuity with sciatic nerve, with subsequent serial MRI findings suggesting tumor enlargement with cystic degeneration. Increased level of C-reactive protein (CRP) was observed before surgery. During an open biopsy upon tissue sampling, exudates with necrotic tissue were seen. Increased level of CRP and necrotic change suggested the possibility of malignant tumor. Histopathological diagnosis was schwannoma, and group B Streptococcus was detected by culture. After the confirmation of infected schwannoma, enucleation of the tumor was performed. CONCLUSIONS: The report concludes that establishment of a benign pathology is essential when presented with similar clinical findings prior to definitive enucleation of an infected schwannoma.

Nonneoplastic peripheral nerve tumors.

Most of the nonneoplastic tumor-like lesions affecting the peripheral nervous system are rarely encountered. In many situations, a good history of the presenting symptoms can suggest a reactive or infectious neuroma. The physical examination can also suggest an inflammatory or hyperplastic lesion. In some cases, however, the correct diagnosis can only be made at surgery. Nonetheless, awareness of these lesions is important in limiting unnecessarily aggressive surgical procedures. Patients suspected of having nonneoplastic lesions are followed and treated surgically for symptomatic relief or when the diagnosis is unclear. In some situations, the surgical treatment of choice may be debated. Nevertheless, we adopt a conservative approach to these lesions and reserve more aggressive techniques for cases that do not respond to more conservative means.

Delayed tumor onset in transgenic mice fed a low-folate diet.

BACKGROUND: Transgenic mice carrying the human T-lymphotropic virus type 1 tax1 (transactivator) gene develop peripheral nerve sheath tumors with well-characterized times of onset and tissue involvement. PURPOSE AND METHODS: To evaluate the effect of dietary folic acid on age at tumor onset and on the concentration of folate in tissues and tumors, we bred heterozygous transgenic mice and systematically assigned their offspring at weaning (within litters) to a 2 x 2 x 2 factorial arrangement. The three variables studied were 1) the tax1 gene (presence or absence), 2) gender (male or female), and 3) dietary level of folic acid (0.11 or 11.34 mumol folic acid per kilogram of controlled amino acid-based diet). Blood and tissues were collected from tumor-bearing transgenic mice (prior to cachexia) and from nontransgenic littermates, matched whenever possible for gender and diet. RESULTS: Transgenic mice fed a diet containing 0.11 mumol of folic acid per kilogram developed tumors significantly later (92.8 +/- 6.4 days) than did those fed a diet containing 11.34 mumol of folic acid per kilogram (71.9 +/- 3.9 days). Folate concentrations in tumors of mice fed the low-folate diet were approximately one third those in tumors of mice fed the higher folate diet. Brain folate concentrations in mice fed the low-folate diet were less than one half those in mice fed the higher folate diet. CONCLUSION: Results show that the onset of spontaneous tumors can be delayed by feeding mice the lowest level of folate adequate to meet nutritional requirements for normal growth. IMPLICATION: Transgenic animal models of human disease offer great potential for evaluating the role of micronutrients in human carcinogenesis.

Neurofibromatosis and leprosy.

Two patients with neurofibromatosis and leprosy are reported. Both had active lepromatous leprosy and generalized neurofibromata. The bacilli appear in huge numbers within the cytoplasm of the cells making up the neurofibromata, which become distended and resemble lepra cells. Since these cells are believed to derive from Schwann cells, the findings in these patients support the idea that leprosy affects nerves initially by proliferating in Schwann cells and producing changes within them.