[Cerebellopontine angle and internal auditory canal lipomas: report of four cases and review of the literature]. / Lipomas de angulo pontocerebeloso y conducto auditivo interno: serie de 4 casos clínicos y revisión de la literatura.

AIM: Lipomas are exceptional tumors at the Cerebellopontine Angle (CPA) or the Internal Auditory Canal (IAC). We evaluate clinical, histological and radiological characteristics of the cases diagnosed in our Hospital and the results of conservative versus surgical treatment. MATERIAL AND METHODS: We report 4 cases of CPA and/or IAC and review 99 previously reported in the literature. RESULTS: Unilateral tinnitus was the most frequent symptom (100%). All lesions showed hyperintensity on T1 and hypo/isointensity on T2--weighted MNR images. Two patients underwent a retro-sigmoidal approach without complete tumoral resection and with additional neurological consequences. Another two cases were followed up by annual MNRs. During the follow-up period (4.2 years average), neither clinical nor radiological changes were detected. CONCLUSION: The surgical resection of CPA y/o IAC lipomas is associated to a significant morbidity due to the high vascularization and the dense adherence of these lesions to the surrounding tissues. The MNR is the suitable technique for differential diagnosis between lesions at this location.

[Abnormality of the lower cranial nerves as a symptom of Chiari's syndrome]. / Alteración en los pares craneales bajos como sospecha de un síndrome de Chiari.

Dysfunction of the last cranial pairs can occur in some neurological diseases, such as Chiari's malformation. This entity causes herniation of the cerebellar amygdalas through the foramen magnum, producing descent of the brainstem and traction on the lower cranial pairs. This dysfunction occurs in 57-70% of patients with this malformation, which is why the disease may be diagnosed in the ENT clinic. Clinical suspicion of this entity after exhaustive examination of the patient, early disease diagnosis and correct selection of surgical treatment can alleviate major symptoms and prevent neurological complications in some cases.

[Bacteriology of surgical wound infections in oncological head and neck surgery]. / Bacteriología de las infecciones de la herida quirúrgica en cirugía oncológica de cabeza y cuello.

Surgical wound infections are a frequent complication of head and neck cancer surgery. In a group of 159 consecutive patients we analyzed bacteriological cultures from 21 with suppurative draining from the wound. In 3 cases cultures were monomicrobial, in 12 cultures were polymicrobial, and in 6 no bacterial isolate was obtained from the cultured material. Gram-positive aerobes were the most frequent bacteria (54%), followed by gram-negative aerobes (38%) and anaerobes (8%). No relation was found between bacteriological profile, antibiotic prophylaxis, tumor site, tumor stage, or surgical procedure.

[The incidence and distribution of accidents with biological fluids among health personnel and the general population]. / Incidencia y distribución de accidentes con fluidos biológicos en personal sanitario y población general.

OBJECTIVES: To assess the informative usefulness of the Registry, to calculate the incidence rates of accident with biological fluids among health care workers and in the community, to know about the postaccident rate of seroconversion to HIV and to identify risk groups. METHODS: A descriptive study of the HIV records file of the Registry of Accidental Contacts to Biological Fluids in the Clinic Hospital of Zaragoza was conducted, between January 1987 and September 1993. The registry includes the reports of health care workers and the general population of Health Area III in Aragón (Spain), except for the Calatayud's Hospital. Incidence rates, rate ratios and their 95% confidence intervals were calculated. RESULTS: A total number of 595 accidents were reported, in none of them and HIV infection occurred subsequently. The incidence rate in health care workers was of 1.7 reports per 100 workers per year, while in the community it was of 8.1 per 100,000 people. The housekeeping staff was the group with a higher incidence (rate = 6.7; 95% IC: 3-14.8) and the type of accident more frequently described was needlestick injury. CONCLUSIONS: The incidence of reported accidents has increased in the community and in health care workers, which may be due to the increase in the reporting. In health care workers, the incidence in 1993 was within the range reported from other countries. The perception of risk is universal after accidents with unknown biological fluids. The correct disposal of material with biological contamination should be the more important preventive action.

[Malignant melanoma of the nasal cavity and paranasal sinuses]. / Melanomas malignos de las fosas nasales y los senos paranasales.

Malignant melanomas represent about 3% of all nasosinusal neoplasms. They usually are located in the nasal septum and their maximum incidence is in the sixth and seventh decades. In the early stages they are asymptomatic, which delays diagnosis and reduces the possibilities of cure to 15-30%. Eight cases of nasosinusal melanoma are reported and their characteristics are reviewed with special attention to prognostic factors.

Proliferating cell nuclear antigen (PCNA) as a marker of dysplasia in oral mucosa.

The development of head and neck cancer has been proposed to be a multistep process, with accumulation of genetic and phenotypic alterations resulting from carcinogen exposure. Proliferating cell nuclear antigen (PCNA), also called cyclin, is a 36-KD auxiliary protein of DNA polymerase-delta, that has been found to be a useful marker in immunocytochemical studies of cell proliferation because its expression correlates with the proliferative state of the cell. PCNA expression was analyzed in 10 samples of normal mucosa, 23 benign oral lesions (18 hyperplasia and 5 oral lichen plani), 10 oral lesions with epithelial dysplasia, and 10 dysplastic epithelia adjacent to tumors. Immunocytochemical stained sections were scored for the presence or absence of suprabasal PCNA positivity regardless of location. The results indicate that the PCNA expression in the suprabasal layers increased with the degree of epithelia dysplasia and in the samples of histological dysplastic epithelium adjacent to the tumors, while the percentage of suprabasal PCNA expression was insignificant in the samples of normal oral mucosa and benign oral lesions. The authors conclude that suprabasal PCNA expression could be a marker of dysplasia in oral mucosa, indicating a special proliferative cellular state in those lesions.

Some histopathological and clinical correlations in oral squamous cell carcinoma.

Oral squamous cell carcinoma (SCC) is an important health problem that causes high mortality and morbidity. Correlations between some clinical and histopathological parameters were studied in 37 oral SCC. Some interesting aspects in oral SCC arising from precancerous lesions were found such as smaller size and a lower TNM stage at the moment of diagnosis. Histological and clinical differences were also found between tumors invading deep tissues by little groups of dissociated malignant cells and those invading by big masses of malignant cells. The possible significance of the intensity of peritumoral eosinophilic infiltrate was also studied.