Thirty-nine (6.5%) latent thyroid carcinomas were found in 600 thyroid glands removed at autopsy in Oporto Medical School Laboratory of Pathology. The prevalence of latent thyroid carcinomas was significantly higher in women (sex ratio 4.3:1) and in elderly people (p less than 0.005) and appeared to be independent from the existence of another malignant neoplasm. The mean thyroid weight and the concurrent thyroid pathology of patients with thyroid carcinomas were not significantly different from those of patients without them. The study of cervical lymph nodes in the first 400 autopsies did not show any significant difference concerning histologic pattern, number of germinal centers and sinus histiocytosis between patients with thyroid carcinomas and those without them. Further investigation is required to evaluate the role of host factors on the peculiar characteristics of latent thyroid carcinomas.

No abstract

Although cognitive dysfunction is a common finding in patients with acquired immunodeficiency syndrome (AIDS) its pathogenesis remains controversial. Given the involvement of the hippocampal formation in the processing of cognitive information and the scarcity of quantitative studies in this brain region, we have examined, using stereological methods, the hippocampal formations of AIDS patients. The study was performed in ten AIDS patients and ten age-matched controls. All cases were male. The Principle of Cavalieri was applied to estimate the volume of the layers of the dentate gyrus and of the CA3 and CA1 hippocampal fields. The fractionator and the nucleator were used as estimators of the total number, and mean somatic and nuclear volumes of the neurons in the cell-containing layers of all hippocampal subdivisions. No cell death was detected in AIDS patients but the global volume of their hippocampal formations was significantly decreased due to the reduced volume of its layers, mainly the cell-containing layers. Furthermore, the somatic and nuclear volumes of the neurons in the hippocampal formation were significantly decreased in AIDS patients. No correlation was found between the estimates obtained and the presence or absence of neurological involvement. Our results show that neurons in the hippocampal formation of AIDS patients display marked morphological changes, despite the maintenance of their total number. These alterations are likely to lead to dysfunction of the hippocampal circuitries and, thus, might contribute to explaining the dementia features which occur in this condition.

We report a patient with cutaneous papular xanthomatosis who 4 years later developed a CD3(-/+dim)/CD4(+) T-cell lymphoma. Pruritic xerotic non-erythrodermic skin, eosinophilia and hyper-IgE were present and erroneously classified as atopic dermatitis. Flow cytometry and DNA ploidy analysis of both blood and skin lymphocytes, skin histology and blood T-cell receptor gene rearrangement studies confirmed diagnosis of T-cell lymphoma. Monoclonal CD3(-/+dim)/CD4(+) T-cells were especially prone to the synthesis of IL-13, a cytokine that is involved in IgE-secretion, and comprised both a medium (diploid) and large (hyperploid) sized T-cell populations with a similar immunophenotype. The majority of the normal residual T-cells were large granular lymphocytes, expressed activation-related and natural-killer-associated markers and secreted high levels of interferon gamma, suggesting that they might correspond to active cytotoxic cells directed against the neoplastic T-lymphocytes.