Abdominopelvic sarcoma of perivascular epithelioid cells. Report of four cases in young women, one with tuberous sclerosis.

The perivascular epithelioid cell has been proposed to be the unifying proliferating cell type in a number of lesions such as angiomyolipoma, lymphangiomyomatosis, clear cell "sugar" tumor and renal capsuloma. With the exception of rare examples of angiomyolipoma, they are non-metastasizing. We report four examples of a new member of this family of perivascular epithelioid cell neoplasms that occur in abdominopelvic location and show metastatic properties. The patients, all women, were aged 19 to 41 years (mean, 32), and presented with a tumor mass involving the serosa of the ileum, uterus or pelvic cavity. Morphologically, the tumors were composed of sheets of large polygonal cells with glycogen-rich clear or eosinophilic cytoplasm and moderately pleomorphic nuclei, traversed by a delicate vasculature, mimicking clear cell carcinoma. There were areas of coagulative necrosis and occasional mitotic figures. Intracytoplasmic brown pigment was present in two cases. Spindly cells, smooth muscle and fat were absent. Lymphovascular invasion was present in all, lymph node metastasis was documented in two and metastasis to the ovary was present in one case. Two patients developed widespread metastatic disease after 10 and 28 months from diagnosis. One patient showed the clinical signs of tuberous sclerosis. In spite of the epithelial-like appearance, the tumor cells were negative for epithelial markers but were strongly positive with the melanogenesis-related marker HMB45. Another melanogenesis marker (MART-1) was positive in two cases. Other markers including S-100 protein, vimentin, muscle-specific actin, desmin and chromogranin A were negative. Thus, these tumors are not readily classifiable in the existing schema of known entities, and show overlapping morpho-phenotypic features of clear cell "sugar" tumor of the lung and epithelioid angiomyolipoma. We consider them as sarcomas composed of a pure population of uncommitted perivascular epithelioid cell, that lack modulation toward smooth muscle or adipose cells.

Calretinin. A selective marker of normal and neoplastic mesothelial cells in serous effusions.

OBJECTIVE: To document that a polyclonal antiserum to calretinin, a 29-kd calcium-binding protein, consistently decorates normal and tumor mesothelial cells in cytologic preparations. STUDY DESIGN: Thirty-three archival cytologic specimens from eight patients with histologically confirmed malignant mesothelioma and 13 from patients with metastatic serous effusions were destained and then immunostained with anticalretinin antiserum. For investigation of cell suspensions, four pleural fluids were incubated with anticalretinin antiserum. After cytocentrifugation the specimens were stained in accordance with the alkaline phosphatase anti-alkaline phosphatase (APAAP) method. For electron microscopic examination the cell suspensions were then incubated with gold-labeled antirabbit antibody. RESULTS: The diagnostic sensitivity of this new immunocytochemical approach reached 100% for the eight malignant mesotheliomas investigated. Only 3 of the 13 adenocarcinomas metastatic to the serous membranes included in this study were weakly reactive, accounting for 81% specificity. Binding of anticalretinin antiserum to living mesothelial cells was consistently documented in all four cases investigated. CONCLUSION: Calretinin is a very useful marker for positive identification of normal and tumor mesothelial cells in serous effusions.

[Polyomavirus infections of the urinary tract. Cytologic and ultrastructural features]. / Infezione da poliomavirus delle vie urinarie. Aspetti citologici ed ultrastrutturali.

The cytopathology of viral infections has some limitations, since the cellular changes provide only an indirect evidence of the underlying disease, and the diagnosis should always be confirmed by virologic methods. We report here one case of Polyomavirus infection in a renal transplant recipient, in which the cellular changes observed in Papanicolaou-stained voided urine specimen were consistent with viral infection. Transmission electron microscopy (TEM) provided a simple and relatively quick identification of viral particles, whose size and morphology were typical for human Polyomavirus. Immunoelectron microscopy (IEM), using colloidal gold technique, confirmed the diagnosis. The morphological criteria used in differential diagnosis and the advantages and limitations of the method are discussed.

Interstitial leucocyte infiltration in primary glomerulonephritis: extent and composition analysis.

In the interstitial cell infiltrates associated with primary glomerulonephritis, approximately the same cellular composition has been found, T cells being predominant, monocytes fewer, and B cells least. Cell composition did not seem to be related to the cell density; the lowest percentages of monocytes have been observed with either very high (FSGS) or very low (MGN) cell densities; and the highest percentages of T cells, with either the highest (FSGS) or the lowest (MGN) cell densities. On the other hand, some relationship seemed to exist with the cell distribution in the interstitium. The cell composition was nearly the same in diffuse and disseminated patterns, but was markedly different in nodular (focal) cell infiltrates; T cells were always in first place, but B cells instead of monocytes were in second place. Furthermore, IL2-receptor-presenting cells have been more often observed in nodular (focal) than in both diffuse and disseminated patterns, and more markedly in nonjuxtaglomerular than in juxtaglomerular noduli (foci). In conclusion, cell composition of interstitial infiltrates seems to reflect a cell-mediated immune reaction, leading to all interstitial cell infiltrates associated with primary glomerulonephritis. It is conceivable that the nodular (focal) pattern of distribution might correspond to a discrete mechanism and have a different meaning.

Ultrastructure of spermiogenesis in men with congenital absence of the vasa deferentia.

Spermiogenesis has been investigated in four cases of agenesia of vasa deferentia. During acrosome formation various anomalies gave rise to late spermatids with deformed heads. Chromatin condensation proceeded normally, but completion of this process appeared to be delayed. Redundant nuclear membranes frequently persisted at the basal region of the nuclei in mature spermatozoa, which occupied niches within Sertoli cells, as the tubules had no lumen. Flagellar structure was normal. These findings support the view that the altered local milieu and variations in acrosome formation may induce the observed anomalies.

Testicular biopsy of secretory azoospermia: electron and light microscopic analysis.

The histological and ultrastructural features of testicular cells were examined in testes with secretory azoospermia in seven patients with germinal cell arrest, two with Sertoli-cell-only; and one with tubular hyalinization. Germinal cell arrest was characterized by the presence of spermatogonia AD, AP, B, and some primary spermatocytes: these cells had similar ultrastructural features typical of the adult normal testis. Sertoli cells contained large number of various lipid inclusions and lipofuscin bodies. The multilayered peritubular wall presented increased collagen fibers. The cytoplasm of Leydig cells was filled with dilated vesicles of smooth endoplasmic reticulum and precursors of Reinke crystalloids. A blockage in the seminiferous tubules occurred after puberty, when tubular components, peritubular wall and Leydig cells had reached maturity.

Ultrastructure of acrosomal malformations in men with obstructive azoospermia.

Testicular biopsies from ten infertile men with obstructive azoospermia were evaluated by light and electron microscopy. Light microscopic analysis revealed normal testicular pattern with active spermatogenesis and many spermatozoa. At ultrastructural level the majority of early spermatids presented acrosomal abnormalities that become evident during the approach of the acrosomal vesicle to the anterior pole of the nucleus, and in subsequent maturational stages; these spermatids continue their development until mature spermatozoa with malformed acrosomes. The type of malformation was very similar in all cases observed and was associated with the same type of seminiferous tubule pattern in patients with the same type of azoospermia. The abnormalities at acrosomal level were related to an abnormal differentiation rather than to degenerative changes. Acrosomal disturbance did not influence nucleus morphology or chromatin condensation.