Donata Bellis

Leiomyoma and neurilemoma: Report of two unusual non-epithelial tumours of the thyroid gland

Two primary spindle cell tumours of the thyroid are described showing light microscopic features of leiomyoma and neurilemoma respectively. The origin from smooth muscle and nerve sheath was confirmed by both immunohistochemical reactions and ultrastructural findings. Review of the literature reveals only one case of leiomyoma and three cases of neurilemoma reported as developing within the thyroid gland. Our observations further support the view that leiomyoma and neurilemoma may occur at this unusual site and are recognizable entities.

Asbestos lung burden and asbestosis after occupational and environmental exposure in an asbestos cement manufacturing area: a necropsy study

OBJECTIVE: The largest Italian asbestos cement factory had been active in Casale Monferrato until 1986: in previous studies a substantial increase in the incidence of pleural mesothelioma was found among residents without occupational exposure to asbestos. To estimate exposure to asbestos in the population, this study evaluated the presence of histological asbestosis and the lung burden of asbestos fibres (AFs) and asbestos bodies (ABs). METHODS: The study comprises the consecutive series of necropsies performed at the Hospital of Casale Monferrato between 1985 and 1988. A sample of lung parenchima was collected and stored for 48 out of 55 necropsies. The AF concentration was measured with a TEM electron microscope with x ray mineralogical analysis. The ABs were counted and fibrosis evaluated by optical microscopy. The nearest relative of each subject was interviewed on occupational and residential history. Mineralogical and histological analyses and interviews were conducted in 1993-4. RESULTS: Statistical analyses included 41 subjects with AF, AB count, and interview. Subjects without occupational exposure who ever lived in Casale Monferrato had an average concentration of 1500 AB/g dried weight (gdw); Seven of 18 presented with asbestosis or small airway lung disease (SAL). G2 asbestosis was diagnosed in two women with no occupational asbestos exposure. One of them had been teaching at a school close to the factory for 12 years. Ten subjects had experienced occupational asbestos exposure, seven in asbestos cement production: mean concentrations were 1.032 x 10(6) AF/gdw and 96,280 AB/gdw. Eight of the 10 had asbestosis or SAL. CONCLUSION: The high concentration of ABs and the new finding of environmental asbestosis confirm that high asbestos concentration was common in the proximity of the factory. Subjects not occupationally exposed and ever living in Casale Monferrato tended to have higher AB concentration than subjects never living in the town (difference not significant). The concentrations of ABs and AFs were higher than those found in other studies on nonoccupationally exposed subjects.

Role of iron in asbestos-body-induced oxidant radical generation.

Asbestos bodies (AB) were harvested from human lung tissue digests and isolated from uncoated asbestos fibers. Samples containing 1000 AB were added to a reactive solution to investigate the ability of AB to oxidize deoxy-D-ribose and generate reactive oxygen species (ROS) in the presence of ascorbate and hydrogen peroxide as determined by formation of thiobarbituric acid (TBA)-reactive products. Three types of asbestos fibers were tested for comparison, since they are known to be able to produce ROS. The absorbance values measured with 1000 AB were significantly higher than those observed with 1000 fibers of the three types of asbestos. Since in our reaction system the only source of transition metals was the iron-rich AB, data suggest iron derived from the ferritin coating of AB was involved in oxidant generation. Addition of iron to AB enhanced TBA-reactive product formation, while chelation of Fe with deferoxamine reduced this reaction. Hydroxyl radical scavengers 1,3-dimethyl-2-thiourea (DMTU) and mannitol (MN) also effectively blocked TBA-reactive product generation. Data indicate the importance of Fe in AB-induced oxidant damage. With the addition of polymorphonuclear leukocytes (PMN) to AB, incubation in the reactive solution gave very high amounts of TBA-reactive products, but using a reactive solution devoid of ascorbate, very low amounts of TBA-reactive products were generated. In the latter condition, the superoxide of cell membranes probably reduced and removed iron from AB-coating ferritin, but less effectively than ascorbate. Further after the possible reoxidation of Fe2+, Fe3+ could be coordinated by lactoferrin. Since such availability of reductant is never approached in living systems, the iron in the AB coating is unlikely to function as a catalyst of Fenton-type reactions in vivo.

Minimal pathologic changes of the lung and asbestos exposure.

A group of 199 autopsy subjects was investigated for minimal pathologic pulmonary changes possibly resulting from asbestos exposure. According to the standards proposed by the Pneumoconiosis Committee of the College of American Pathologists, features consistent with asbestosis grade 1 (AG1) include findings of bilateral pleural plaques, high concentrations of asbestos bodies (ABs) in digested lung tissue, and a history of occupational risk. Similar changes without evidence of ABs on histologic section and referred to as small airway lesions (SALs) present a less well-correlated association. In this study, SALs showed significant differences when compared with the features observed in subjects without possible asbestos-related pulmonary fibrotic changes. Minimal bronchioloalveolar fibrotic changes with concomitant presence of ABs can be considered a mild pneumoconiotic lesion (AG1), and SALs may be regarded as an additional indicator of asbestos exposure.

Light microscopic and immunohistochemical evaluation of vascular and neural invasion in colorectal cancer.

One hundred and sixty consecutive surgically removed colorectal carcinomas were investigated on histological sections stained with Hematoxylin and Eosin (H & E). Vascular and neural neoplastic invasion was found in 49 (30.6%) and 50 (31.3%) patients. In addition, immunohistochemical investigation was performed on step sections to those stained with H & E in the first 50 patients, using anti-human Factor VIII related antigen, anti-actin and anti-protein S 100 antisera. The percentages of positive cases for vascular invasion in this group of 50 patients were 20% on H & E sections and 62% on those stained with anti-Factor VIII and anti-actin antisera. Neural infiltration was identified in 14% of cases on H & E sections and in 70% of cases on anti-protein S 100 treated sections. Since vascular and neural infiltration are known to be ominous prognostic factors, their identification has great clinical relevance. The use of these simple immunohistochemical stains, using readily available antisera on formalin-fixed material, is recommended as routine procedure in surgical pathology laboratories.

Malignant peritoneal mesothelima in a 17-year-old boy with evidence of previous exposure to chrysotile and tremolite asbestos

We describe a case of malignant peritoneal mesothelioma arising in a 17-year-old boy. The diagnosis was based on a comprehensive study including light microscopy, histochemistry, immunohistochemistry, evaluation of the clinical course, and autopsy examination. Analytical transmission electron microscopy showed a concentration of 510,000 asbestos fibers/g dry lung tissue. The fibers were represented by chrysotile (62%) and tremolite (38%) asbestos. About 40% of the total fibers were longer than 5 microns. The presence of tremolite fibers was probably due to environmental exposure to contaminated cosmetic talc. This is the first reported case of pathologically proven exposure to asbestos dust in malignant mesothelioma of childhood and adolescence.

Coated and uncoated lung mineral fibres in subjects with and without pleural plaques at autopsy.

The lung concentration of coated and uncoated mineral fibres of more than 10 micron in length was determined by light microscopy in 57 autopsied subjects (23 out of which professionally exposed to asbestos) with pleural plaques but no other asbestos-related diseases. Comparisons were made with 57 controls matched for sex, age and smoking habits, who did not show any asbestos-associated diseases or history of previous occupational exposure. Subjects with pleural plaques had a median concentration of coated fibres consistently greater than that observed in those without. However, no substantial differences were found between the two studied groups when uncoated and total fibres were considered. The present study suggests that the factors related to the fibre coating and to the pleural plaque formation may be indirectly connected, but not necessarily restricted to the number and nature of the fibres, or to the professional or environmental conditions of exposure.

Atypical changes of respiratory epithelium after heart-lung transplantation: A Case Report

Atypical changes of bronchial respiratory epithelium in a combined heart-lung transplantation recipient are reported. The occurrence of diffuse hyperplasia, squamous metaplasia and dysplasia with foci of disorganized structure of the respiratory epithelium is described. These epithelial changes in the bronchial tree were considered to have arisen after transplantation; their origin, significance and possible evolution are discussed.