Phyllodes tumour of the breast: immunohistochemical study of 37 tumours using MIB1 antibody.

In our study, the expression of Ki-67 antigen in phyllodes tumours of the breast was investigated in order to estimate its significance in assessing the grade of malignancy and in predicting the clinical behaviour of these tumours. Formalin-fixed and paraffin-embedded tissue specimens of 37 cases of phyllodes tumour of the breast (eight graded as malignant and 29 as benign according to histopathological criteria) and 20 breast fibroadenomas were stained by an immunoperoxidase technique, using the monoclonal antibody MIB1 directed against cell proliferation-associated Ki-67 antigen. A MIB1 index was calculated to express the percentage of MIB1 positive proliferating stromal cells. Our data indicate that there are statistically significant differences in MIB1 indices between histologically benign and malignant phyllodes tumours (alpha = 0.001), between benign phyllodes tumour and fibroadenoma (alpha = 0.01), and between malignant phyllodes tumour and fibroadenoma (alpha = 0.001). Our results also indicate a good correlation between the conventional grading of phyllodes tumours based on histological criteria and MIB1 indices. However, little predictive value of the MIB1 index in phyllodes tumours of the breast can be derived from our study.

Cytoplasmic liver cell inclusions--a typical feature of porphyria cutanea tarda--are absent in porphyria-related hepatic neoplasias.

Crystalline cytoplasmic needle-shaped inclusions in hepatocytes are considered to represent a specific morphological feature of porphyria cutanea tarda (PCT) and experimental PCT-like porphyrias. The cytoplasmic inclusions, however, are absent in hyperplastic hepatic nodules and hepatocellular carcinomas arising in the course of these conditions. It is assumed that porphyrins and related substances accumulated in hyperplastic and neoplastic hepatic lesions differ from those found in non-neoplastic liver tissue: the highly carboxylated porphyrins are stored in both sites, the crystal-forming substance only in non-proliferating liver tissue.

[Mantle cell lymphoma (MCL)--histopathology and clinical features]. / Lymfom z plást'ových bunek (MCL)--histopatologické a klinické znaky.

Mantle cell lymphoma (MCL) has been established as a clinicopathologic entity in 1991. A histopathologic and immunohistochemical study of 16 cases of MCL was performed in order to demonstrate differential diagnostic aspects. MCLs were composed of small and medium-sized B cells assuming the appearance of centrocytes. The growth pattern was diffuse in 9 cases and that of follicle mantle zone type within at least partially present nodular parts in 16 cases. The immunohistochemical staining for CD23 antigen was negative in tumour cells whereas the strong immunoreactivity of follicular dendritic cells (FDC) decorated residual FDC network. Seven cases of MCL were examined for the presence of translocation t(11;14)(q13;q32) using polymerase chain reaction. Despite histomorphological features compatible with a diagnosis of low-grade lymphoma, MCL has a worse prognosis and more aggressive behaviour than other types of small cell lymphomas, such as small lymphocytic lymphoma and follicle centre lymphoma.

Calcifying fibrous pseudotumour of visceral peritoneum.

AIMS: Calcifying fibrous pseudotumour, a recently characterized rare but distinctive lesion, has been reported previously only in soft tissues and in the pleura. We describe four cases of calcifying fibrous pseudotumour which arose in the visceral peritoneum of the small bowel and stomach. METHODS AND RESULTS: In contrast to the calcifying fibrous pseudotumour of soft tissues which generally occurs in children, all four cases in our report occurred in adults. We consider the calcifying fibrous pseudotumour to be a distinctive tissue reaction. CONCLUSIONS: Its characteristic appearance of concentric whorls of lamellated collagen associated with psammoma bodies and other forms of dystrophic calcification is entirely different from all other lesions displaying hyaline collagenous deposits, such as inflammatory pseudotumour, desmoid, hyalinizing granuloma or fibrous plaques of peritoneum.

Glassy hyaline globules in granular cell carcinoma, chromophobe cell carcinoma, and oncocytoma of the kidney.

The presence of glassy hyaline globules (GHG) in renal carcinomas has been rarely emphasized in the literature. We studied the frequency of these globules in numerous renal carcinomas, including granular cell, mixed clear cell/granular cell, papillary renal cell, and chromophobe renal cell carcinoma, as well as oncocytomas. GHG are eosinophilic bodies in the hematoxylin-eosin stained sections with a size ranging from 1 to 30 micrometer and strongly positive with the periodic acid-Schiff (PAS) histochemical stain. Ultrastructurally, they are seen as amorphous secretion inside of the cisternae of the rough endoplasmic reticulum. GHG were found in 49 of 64 cases of granular cell and mixed clear cell/granular cell renal carcinomas and in 5 of 33 papillary renal cell carcinomas. No GHG were found in 22 cases of chromophobe cell carcinomas and 26 renal oncocytomas. Our findings suggests that GHG are a characteristic feature of granular cell carcinomas, mixed clear cell/granular cell renal carcinomas, and in a small minority of papillary renal cell carcinomas. In addition, it suggests that the presence of GHG in a renal cell tumor may be of aid for excluding a diagnosis of chromophobe cell carcinoma or oncocytoma.