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Biomedical subjects

B Weynand

Publications and source records attributed to B Weynand.

At least 37 records · Page 2Linked to original sources
PubMed1999

Calcifying fibrous pseudotumor (CFPT): a patient presenting with multiple pleural lesions.

Calcifying fibrous pseudotumor (CFPT) is a rare pseudotumoral lesion initially described in the subcutaneous and deep soft tissues. More recently, 3 cases were reported in the pleura. We report an unusual presentation associating miliary pleural lesions with a single soft tissue lesion in a 29-year old, asymptomatic female patient. The multitude of pleural lesions prevented complete excision. Although the present case confirms an indolent process, the pathogenesis and long-term prognosis remain undetermined.

Adult↗
PubMed1999

Motilin-producing liver and bone metastases evidenced 14 years after resection of a rectal polyp.

A 62-year-old man with a history of a resected rectal polyp was diagnosed 14 years later with right liver and multiple bone metastases. The liver biopsy showed a malignant epithelial tumor that was positive for neuron-specific enolase immunostaining and negative for chromogranin. Electron microscopy was characteristic of that for an endocrine tumor. Most circulating hormonal peptide levels were within normal ranges and only motilin level was elevated. On the right hepatectomy, the three large metastases had a histologic picture suggestive of an endocrine tumor. Immunohistochemistry revealed in some areas numerous tumor cells expressing motilin, and a few cells were strongly positive for pancreatic polypeptide and somatostatin. The retrospective analysis of the rectal polyp showed a similar histology and immunohistochemical profile, indicating that this lesion was the primary tumor. Motilin-positive cells from one of the hepatic lesions were identified on semithin sections and further processed for electron microscopy. Neurosecretory granules were numerous in all cells. Immunoelectron localization enabled us to characterize the motilin-containing neurosecretory granules, which had a mean diameter of 168.3x38.1 nm. Although not all tumor cells were motilin-positive, a diagnosis of motilinoma for the rectal polyp and its hepatic and bone metastases was proposed.

Biopsy↗
PubMed1999

Diabetes mellitus induces a thickening of the pulmonary basal lamina.

Long-term diabetes mellitus (DM) is characterized by widespread alterations of basal lamina (BL). The purpose of the present work was to verify whether the lung is also a target organ damaged in DM. Electron microscopy was performed on lung and kidney samples (autopsic material) from 6 diabetics and 6 control subjects studying the thickening of BL of different structures (alveolar epithelial BL, endothelial capillary BL, both fused BL, BL of the glomerular capillary endothelium and BL of the renal tubules). The results were as follows: (1) alveolar epithelial BL (mean +/- SD) = 121 +/- 11 nm in controls and 176 +/- 27 nm in diabetics (p < 0.01), (2) endothelial capillary BL = 164 +/- 14 nm in controls and 223 +/- 27 nm in diabetics (p < 0.001), (3) both BL fused = 222 +/- 23 nm in controls and 316 +/- 62 nm in diabetics (p < 0.01), (4) BL of the glomerular capillary endothelium = 374 +/- 44 nm in controls and 626 +/- 249 in diabetics (p < 0.05) and (5) BL of the renal tubules = 602 +/- 94 nm in controls and 1,083 +/- 376 nm in diabetics (p < 0. 05). All parts of the lung are equally affected by DM. The thickening of BL is of the same magnitude in lung and kidney. There is no relationship between the thickening of the lung BL and the known duration and type of DM.

Adult↗
PubMed1999

Prognostic factors in squamous cell carcinomas of the head and neck.

This review will focus on prognostic factors that can be disclosed by the pathological and molecular analysis of squamous cell carcinomas of the head and neck. The following pathological prognostic factors are considered and discussed: location, histopathology, lymph node metastasis. In addition, a number of molecular genetic markers have been identified such as: DNA content, chromosomal abnormalities, cell proliferation, RAS gene family, epidermal growth factor and its receptor, tumor-suppressor genes, cell adhesion molecules and proteinases.

Biomarkers, Tumor↗
PubMed1998

Lung granulomatosis in a dental technician.

BACKGROUND: Dental technicians are potentially exposed to various occupational dusts and chemicals. Not surprisingly, occupational related lung diseases have been documented in this population. METHODS: We describe the case of a dental laboratory technician presenting progressive exertional dyspnea and cough. We used lung function tests, computed tomography, histological examination, mineralogical and immunological studies to characterize his condition. RESULTS: Lung function studies disclosed a restrictive pattern with a low diffusion capacity. A high-resolution CT scan revealed the presence of micronodules in both lungs corresponding to non-caseating foreign body granulomas at histological examination. Mineralogic studies showed the presence of silica, silicates, and aluminum. The lymphocytic transformation test was positive with the bronchoalveolar lavage for beryllium. CONCLUSIONS: This dental technician developed pulmonary granulomatosis. Combined histological, mineralogical, and immunological studies led us to consider the diagnosis of pneumoconiosis most likely related to occupational exposure to beryllium and aluminum.

Adult↗
PubMed1998

Cytopathological features of solitary fibrous tumor of the pleura: a study of 5 cases.

Solitary fibrous tumor is a rare lesion of serosal membranes. In a pleural location, it may be confused clinically with a localized mesothelioma or a peripheral lung tumor. A transthoracic needle aspiration can be done to obtain material for a diagnosis in these easily accessible tumors. In the literature, there are only sporadic reports of cytology of solitary fibrous tumor in pleural fluid or in material obtained by percutaneous fine-needle aspiration. We had the opportunity to study five such cases by cytology and biopsy and in four cases we could study the resected specimen as well. We want to emphasize the possibilities of approaching diagnosis by cytologic material. A more precise diagnosis can be made if immunohistochemistry can be applied on a cell block or a concomitant biopsy specimen. We shall discuss the differential diagnosis of these tumors on cytologic material and/or biopsy and the usefulness of the CD34 antibody.

Aged↗
PubMed1998

Tuberculous mediastinal lymphadenopathy.

We report about 2 cases of isolated mediastinal tuberculous lymphadenitis presenting without parenchymal infiltrates. Although rare, this mode of presentation reminds the clinician that tuberculosis has to be included in the differential diagnosis of mediastinal masses even in the absence of parenchymal lesion. Both cases illustrate the value of mediastinoscopic examination to assess the diagnosis.

Aged↗
PubMed1998

Clara cell protein (CC16) in pleural fluids: a marker of leakage through the visceral pleura.

Pleural fluid (PF) proteins either derive from serum by diffusion or are locally secreted within the pleural space. Another hypothetical origin is a leakage of lung secretory proteins across the visceral pleura. To test this hypothesis, we investigated the occurrence, sources, and determinants in PF of CC16, a small-size and readily diffusible protein of 16 kDa secreted by bronchiolar Clara cells. CC16 concentration was determined by a sensitive latex immunoassay in serum and PF of 117 subjects (86 exudates and 31 transudates) and, for purpose of comparison, in ascites samples from another group of 38 subjects (7 exudates and 31 transudates). CC16 was also studied in serum and PF of normal rats and in rats with pleural exudate induced by alpha-naphthyl-thiourea (ANTU). The levels of CC16 in PF and ascites were highly correlated with that in serum, suggesting a diffusional exchange across the pleural/blood and peritoneal/blood barriers. Whereas CC16 occurs at similar levels in ascites and serum, the protein was found to be more concentrated in PF than in serum in both humans (geometric mean in microg/L, 26.2 versus 14.6, p < 0.0001) and rats (213 versus 16.2, p < 0.001). A local synthesis of CC16 appeared unlikely in view of the lack of CC16-immunostaining in pleura of both species. The only plausible explanation for these findings is that CC16 in PF originates from two sources: diffusion from plasma and a leakage from the lung into the pleural space across the semipermeable visceral pleura. This interpretation is supported by a markedly increased leakage of CC16 in experimental exudates induced by ANTU and the finding of high CC16 concentrations in human transudates associated with congestive heart failure, two conditions wherein PF has been shown to arise from the interstitial spaces of the lung.

Aged↗
PubMed1997

Solitary fibrous tumor of the pleura: a report of five cases diagnosed by transthoracic cutting needle biopsy.

Five patients had a solitary fibrous tumor of the pleura; a well-known but rare entity. In all cases, biopsy by a transthoracic cutting needle (Tru-Cut; Travenol; Deerfield, IL) yielded specimens adequate for histologic analysis and gave the clue to the diagnosis. In four patients, surgical resection confirmed the diagnosis. The opportunity for and interest in diagnosing these tumors by transthoracic cutting needle biopsy before surgery are discussed. An accurate diagnosis of solitary fibrous tumors of the pleura can be made by a minimally invasive procedure; this allows for a more informed allocation of surgical resources.

Aged↗
PubMed1996

[Pleural effusion and severe edema of the lower limbs induced by bromocriptine].

High doses of bromocriptine used for treatment of Parkinson's disease may be associated with pleuropulmonary complications. Isolated pleural effusions are a rare manifestation as is lower limbs edema are an exceptionally one. We report the case of a 67-year-old man, treated since five years by a daily dose of 30 mg of bromocriptine for Parkinson's disease, who developed important leg's edema and a few months later an exsudative right pleural effusion. No etiologies were found. Bromocriptine was discontinued. The evolution was characterized by nearly complete resolution of pleural effusion and disparition of lower limbs edema.

Aged↗
PubMed1991

Platelet aggregates in small lung vessels and death during liver transplantation.

10 children who died suddenly during liver transplantation were found at necropsy to have extensive obstruction of small lung vessels by platelet aggregates. In 7 of these patients pulmonary artery pressure changes before death were consistent with acute obstruction of the pulmonary vascular bed. Platelet aggregates were not strikingly increased in blood vessels in other tissues. No single obvious cause for these unusual histological findings could be identified, although the presence of intravascular catheters, perioperative blood and platelet concentrate transfusions, and cellular debris from the liver forced into the circulation during surgery might predispose to platelet aggregation.

Capillaries↗
PubMedDate not supplied

Endoscopic ultrasound guided fine needle aspiration in biliary and pancreatic diseases: pitfalls and performances.

Endoscopic ultrasound guided fine needle aspiration (EUSFNA) has become the most accurate modality for characterization of pancreatic cystic and solid lesions, for differential diagnosis of indeterminate pancreatic masses and for locoregional staging of pancreatic and extrahepatic biliary tumours. EUS-FNA should also be performed in distant lymph nodes, ascites, liver, adrenal and mediastinal metastatic locations. Experienced groups reach a sensitivity over 85% with a 90-100% specificity, a positive predictive value of 98-100%, a negative predictive value of 44-80%, and an accuracy of 75-84% in evaluation of pancreatic masses. Morbidity rate (acute pancreatitis, infection, haemorrhage, perforation) is very low being around 1-2% and risk of peritoneal seeding was shown to be significantly lower than percutaneous CT guided FNA. The performance of this technique is dependent on the endoscopist and cytopathologist experience, the location, size and consistency of the tumour and the number of passes in the lesion. The type of echoendoscope or needle used does not influence the results, whereas it remains debated if presence of the cytopathologist on site might improve FNA performances. These last years, a new liquid-based cytology technique has been developed to process the specimen. Different methods exist to prepare this type of material and all these techniques improve EUS-FNA performance by decreasing the number of inadequate specimens and by increasing the possibility to obtain cell blocks allowing for ancillary techniques such as immunohistochemistry and molecular biology.

Biliary Tract Diseases↗