RESUMEN

Chordoid tumor--synonymous with chordoid sarcoma, parachordoma, and peripheral chordoma--is a very rare neoplasm with histologic similarity to chordoma that is found outside the axial skeleton. A soft tissue chordoid tumor in the gluteus maximus muscle of a 42-year-old man is presented. This tumor had morphologic features identical to a chordoma: nodular growth with vacuolated cytoplasm and myxomatous stroma by light microscopy, positive immunoreaction for cytokeratin and epithelial membrane antigen by immunohistochemistry, desmosomes, intercellular lumina lined with microvilli, and the presence of basal lamina material by electron microscopy. Two similar cases have been reported in the English literature.

Asunto(s)

Asunto(s)

RESUMEN

Gliosarcomas are mixed tumors of the brain containing both malignant neuroectodermal and mesenchymal components. Over 100 cases have been reported within the brain; however, to our knowledge, this is the first reported case located primarily within the spinal cord. Along with a review of the literature, the light, immunohistochemical and ultrastructural findings of a spinal gliosarcoma are reported in a 41-year-old woman with a previously diagnosed oligodendroglioma of the cerebellum 15 years earlier and a concurrent pituitary adenoma. The spinal tumor appears to be morphologically identical to its intracranial counterpart.

Asunto(s)

Asunto(s)

RESUMEN

Granular cell tumors (GCTs) were originally characterized ultrastructurally by the presence of many large lysosomes and angulate bodies (ABs). ABs appear to have been forgotten, and the diagnosis of GCT currently depends solely upon the presence of large lysosomes. Most investigators favor a Schwann cell origin for GCT. Recently, reports of granular tumors with large lysosomes but without ABs have suggested other cells of origin. If the ultrastructural criteria for the diagnosis of GCT were maintained as originally described, many of these granular tumors would not qualify as true GCTs. Two granular tumors that were at first considered GCTs are described. Based on the presence of large lysosomes and the presence or absence of ABs, one tumor was considered a true malignant GCT and the other a benign fibroblastic tumor.

Asunto(s)

RESUMEN

A metastatic spindle cell malignant melanoma with positive immunoreactivity for S-100 protein and HMB-45 antigen and the presence of premelanosomes is described in a lymph node of the neck 11 years after removal of a superficial spreading malignant melanoma from the arm. Ultrastructurally, long, slender microvilli created a pattern with great similarity to an anemone cell tumor. A more solid pattern without microvilli was also present. Despite the abundance of microvilli in the anemone part of the tumor, intracytoplasmic lumina were not observed. In addition, crystalline structures within enlarged mitochondria and intracisternal tubules were noted.

Asunto(s)

Asunto(s)

RESUMEN

It can be difficult to differentiate between epithelial and mixed type mesothelioma and metastatic adenocarcinoma. To distinguish between the two, it has recently been suggested that the presence of abluminal microvilli making contact with collagen fibrils through discontinuities in the basal lamina was characteristic of mesothelioma but not of metastatic adenocarcinoma. This study presents three patients out of 39 who had adenocarcinoma metastatic to the pleural and abdominal cavities, in which direct contact was observed between abluminal microvilli and collagen fibrils. All 39 examples of mesothelioma which were also examined demonstrated this feature. This phenomenon should therefore not be used as a discriminator between mesothelioma and metastatic adenocarcinoma. An additional patient with metastatic adenocarcinoma in an axillary lymph node demonstrates that this phenomenon is not limited to the pleural or abdominal cavities.

Asunto(s)

RESUMEN

A 72-year-old man presented with a 15 x 12 x 5 cm cystic and necrotic tumor involving the superior region of the stomach and the retroperitoneum down to the transverse colon and extending laterally from the left lobe of the liver to the spleen without involving either organ. Light microscopy showed the tumor cells to be arranged in an organoid pattern. Immunocytochemistry showed a strong reaction for desmin and vimentin. Electron microscopy demonstrated features suggestive of an alveolar soft part sarcoma.

Asunto(s)

RESUMEN

Ten cases of malignant mesothelioma (MM), as diagnosed by clinical history and light and electron microscopy, were studied with polyclonal antibodies directed against the basement membrane-specific proteins, type IV collagen and laminin, as well as with monoclonal antibodies which recognize two epitopes of the laminin receptor (LR). All formalin-fixed, paraffin-embedded mesothelioma tissues examined demonstrated intracytoplasmic immunoreactivity for the basement membrane proteins. Extracellular staining was minimal, analogous to the staining reactions observed in adenocarcinomas of the breast and lung, which on light microscopy mimicked the morphologic appearance of MM. Similarly, LRs were identified on MM cells by intense positive staining. Immunoreactivity was also evident on nonneoplastic mesothelioma and adenocarcinoma cells but with greater heterogeneity and less intensity. It may be concluded from these results that (a) malignant mesotheliomas have the ability to synthesize components of the basement membrane; (b) enhanced attachment to extracellular matrix by MM would be anticipated as laminin receptors are present in large numbers on the surface of mesothelioma cells; (c) the reason for lack of intensiveness by MM cells remains speculative; type IV-specific collagenase may play a role in regulating this function in these tumor cells.

Asunto(s)

RESUMEN

Prominent crystalline inclusions were noted in the glomeruli of a 57-year-old man with a 6-month history of swelling and pain in the hands, slight proteinuria, and elevated serum creatinine and BUN. The crystalline inclusions were most prominent in the visceral epithelium but were also noted in endothelial and mesangial cells, in the parietal epithelium, and in the epithelial cells of the proximal tubules. On electron microscopy the crystalline structures were of various geometric shapes but had no definite substructure. Immunofluorescence was negative. The patient was considered to have a hitherto undescribed metabolic disease. Several months later the patient underwent an operation for carpal tunnel syndrome and amyloid deposits, crystalline inclusions similar to those noted in the kidney were observed in the synovial tissue. Shortly after this the patient was found to have multiple myeloma of IgG, kappa type with Bence Jones proteinuria. Lymphoplasmacytic cells in the bone marrow contained the same crystalline inclusions noted in the kidney and synovium. This case therefore seems to represent a new and very rare form of glomerular involvement in multiple myeloma.

Asunto(s)

RESUMEN

We report a rare case of malignant oncocytic carcinoid of the pancreas including the diagnostic immunocytochemical and electron microscopic findings. In addition the tumor shows some unusual ultrastructural features: lamelliform cristae and cytoplasmic and nuclear crystalline structures.

Asunto(s)

Asunto(s)

RESUMEN

Crystalline inclusions were observed on routine cytologic studies of ascitic fluid from a patient with exudative ascites of undetermined cause. These inclusions were polymorphic, but frequently appeared as slender needles. They were seen most often in histiocytes and, less frequently, in mesothelial cells and plasma cells. Extracellular crystals were also seen. The crystals were also present in biopsy specimens of peritoneum, liver and bone marrow. Special studies by polarizing light microscopy, cytochemistry, electron microscopy and immunocytochemistry suggested that the crystals were most probably immunoglobulins synthesized by plasma cells. Some were excreted extracellularly and phagocytized by histiocytes. Further studies indicated that the patient had an indolent plasma-cell dyscrasia, resulting in excessive production of a monoclonal immunoglobulin. The immunoglobulin may have crystallized and become deposited in tissues, inciting chronic inflammatory changes. Massive deposits of crystals in the peritoneum, with the resultant inflammatory reaction, was possibly the cause of the formation of ascites.

Asunto(s)

RESUMEN

An unusual structure resembling an islet of Langerhans was described in the pancreatic ductal epithelium of a presumably normal human male. Further studies to establish the identities of both islet and duct were performed. The original hematoxylin and eosin section served for histological description, as well as for nuclear volume analysis to characterize levels of beta cell polyploidy. The section was restained with Gomori's Chrome Alum Hematoxylin Phloxine to ascertain the presence of islet-like cells and to quantitate the ratio of beta- to non-beta cells. The section was then restained by the Feulgen technique to confirm proportionality between nuclear volume and DNA content. An apparently normal islet in the same section served as control. The combined observations were consistent with the interpretation that the structure is indeed an islet situated within the ductal epithelium. The almost complete absence of polyploid beta cells, however, and the high ratio of non-beta cells:beta cells suggested that it was a young islet. A similarly high proportion of non-beta cells in the control islet, as well as the frequent occurrence of ducts within, or in close proximity to, other islets, suggested that the entire islet organ was under some form of proliferative stimulus at time of resection. Alterations of the ductal epithelium and the secretory contents suggested that the duct was also in the process of transformation. Although the islet had apparently arisen within the ductal epithelium, the ultimate source of the progenitor cells could not be determined from these studies. The relationship of the ductal islet to other well known forms of islet regeneration is discussed.

Asunto(s)

RESUMEN

The aim of this study is to provide a long-term follow-up of patients with tubular carcinoma and to investigate whether the separation of the mixed type of tubular carcinoma, tubular component more than 75%, from invasive ductal carcinoma with a major tubular component (ductal carcinoma MTC), tubular component 50 to 75%, is supported by long term follow-up. For this study 388 consecutive breast carcinomas were selected from the files of the Department of Pathology, Bispebjerg Hospital, Denmark for the years: 1956-59. Twenty tubular carcinomas were found and 16 ductal carcinomas MTC were also identified. For each patient with tubular carcinoma and ductal carcinoma MTC, two controls with ductal carcinoma NOS were selected. The patients in these four groups were followed until 1 April 1982. None of the patients were lost to follow-up. Among the 20 patients with tubular carcinoma, 10 died within this period compared to 37 of the 40 controls. Of the 16 patients with ductal carcinoma MTC, 15 died compared to 29 of the 32 controls. The difference in Kaplan-Meier survival curves between the tubular carcinomas and their controls is highly significant. There is no significant difference between ductal carcinomas MTC and their controls. These findings are not changed significantly when 5, 10, and 20 year survival rates are corrected for expected survival. This study demonstrates long-term survival for patients with tubular carcinoma as compared to ductal carcinoma NOS. There is no difference in long-term survival between ductal carcinoma MTC, tubular component between 50 and 75%, and ductal carcinoma NOS. It therefore seems appropriate to set 75% tubular component as a reasonable cut-off point for the mixed type of tubular carcinoma.

Asunto(s)

RESUMEN

24 renal biopsies from 23 patients with IgA nephropathy (Berger's disease) were examined. This retrospective ultrastructural study focused on extraglomerular vascular structures since information about these structures in IgA nephropathy is lacking. Electron-dense deposits were observed in arterioles in 8 out of 18 biopsies (44%), in which arterioles were available for electron microscopic examination. Deposits were absent in peritubular capillaries and in all arteries. The presence of deposits had no correlation with the patient's blood pressure. The electron-dense deposits represent additional evidence that IgA nephropathy is a monosymptomatic form of a systemic disease that is mediated by circulating immune complexes of heterogeneous origin.

Asunto(s)

RESUMEN

Malignant melanoma originating outside the skin, juxtacutaneous mucous membranes, eyes, and leptomeninges is a very rare neoplasm. Two such primary visceral malignant melanomas from the lung and adrenal are described in detail.

Asunto(s)

RESUMEN

The effect of alpha-difluoromethylornithine (DFMO) treatment on the morphology of African trypanosomes was investigated. For this purpose inbred mice were immunosuppressed and infected with a clone of the protozoan blood parasite Trypanosoma brucei rhodesiense. The mice were then treated with DFMO, an irreversible inhibitor of ornithine decarboxylase, which inhibits polyamine synthesis. DFMO treatment in the absence of host immunity resulted in arrest of cytokinesis of the trypanosomes and many binucleated cells could be seen in blood smears. If mice were infected with a highly virulent trypanosome clone (ETat 1.10), which does not normally transform from long slender (LS) to short stumpy (SS) forms, DFMO treatment caused SS transformation to occur on days 3-4. This morphological SS transformation was substantiated by the presence of diaphorase activity and nuclear and mitochondrial changes. The results suggest a possible involvement of polyamines in the transformation from LS to SS forms.

Asunto(s)

RESUMEN

Four cases of small cell carcinoma of the lung were studied ultrastructurally. The tumor cells contained scattered neurosecretory granules. Areas of the tumor that showed the characteristic crush phenomenon were found to be surrounded by myofibroblasts. It is proposed that the crush phenomenon is caused by contraction of the encircling myofibroblasts. The myofibroblasts and collagen may also cause degeneration and necrosis of the tumor cells. Myofibroblasts have not been observed in other histologic types of carcinoma of the lung.

Asunto(s)