Combined hepatocellular-cholangiocarcinoma with variable sarcomatous transformation.

An adult case of combined hepatocellular-cholangiocarcinoma with variable sarcomatous changes is presented. Histologically, the tumor was composed of hepatocellular carcinoma, cholangiocarcinoma, and sarcomatous portions, including spindle-shaped, pleomorphic, and osteoplastic varieties. There was a transitional cell form between the carcinoma and sarcomatous cells. These tumor elements showed both independent and concurrent metastases. Immunohistochemical examination for keratin revealed positive staining in the tumor cells except for osteoplastic immature cells, whereas vimentin had positive results only in some sarcomatous cells. On the basis of these findings, the possibility of sarcomatous transformation of combined hepatocellular-cholangiocarcinoma was discussed.

Alterations in the distribution of plasma fibronectin and the ultrastructure of podocytes in the peripheral glomerular loops in nephrotic rats.

Glomerular distribution of rat plasma fibronectin was examined during the course of puromycin (PAN)- and daunomycin (DM)-induced nephrosis. In control animals, fibronectin was detected in the mesangial matrix and along the glomerular basement membrane (GBM), closely associated with the plasma membrane of glomerular cells. In peripheral loops, immunoprecipitates were preferentially distributed in the laminae rarae externa and interna. Fibronectin was densely precipitated in a glomerulosclerotic lesion induced by DM at 8 weeks after the injection. In peripheral loops, loss and reconstruction of epithelial foot processes occurred in PAN nephrosis but the change was accompanied by negligible perturbation of fibronectin distribution in the lamina rara externa. In contrast, a remarkable decrease of fibronectin was observed in DM nephrosis, unrelated to the presence or absence of foot processes. The decrease in immunoreactivity for fibronectin in the lamina rara externa seemed to have no association with podocyte attachment to or detachment from the GBM. Plasma fibronectin distributed in the lamina rara externa is not directly involved in the modification of podocyte configuration or podocyte attachment, although its spatial distribution may have some functional significance for preserving the ultrastructure of the GBM.

Quick-freeze, deep-etch studies of renal basement membranes.

The fine structure of the renal (i.e., glomerular, tubular, and capillary) basement membranes was re-evaluated with the aid of a deep-etch replica method. The structure of the laminae rarae interna and externa of the rat glomerular basement membrane (GBM) and laminae lucida of other basement membranes were basically identical in that 6 to 8 nm fibrils were interconnected to form a three-dimensional, polygonal network. By contrast, all of the laminae densa examined were composed of closely packed granules, and a filamentous substructure was identified only in a limited area. These granular components were demonstrated to be an integral component of the lamina densa. From additional observations on the trypsinized bovine GBM, it appeared that the basic structure of renal basement membranes was almost identical, namely, that a three-dimensional fibrillar meshwork existed throughout the individual layers to form a structural framework upon which fine particles were variably attached. In addition, we observed some of the fine structure of the pars fibroreticularis; the laminae densa of the tubular and capillary basement membranes continued to the fibrillar meshwork resembling the structural backbone of the glomerular basement membrane. The network was sometimes directly connected to the extracellular matrix, but more often changed into a rough fibrillar framework and connected to the extracellular matrix.

Evidence of multi-step oncogenesis of oral squamous cell carcinoma.

We examined biopsy samples from one oral cancer and three precancerous lesions of the tongue of an 81-year old woman by polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and sequence analyses using 18 oligonucleotide primer pairs of adenomatous polyposis coli (APC) gene and 5 primers of p53 gene. Normal tongue epithelium adjacent to lesions was used as a control. The four lesions harbored the common mutation of APC gene that was not detected in the control. At codon 1621 in exon 15 of the APC gene there was a C to G substitution resulting in serine (TCA) to stop codon (TGA). No mutation of p53 gene was detected in any samples of the control and three precancerous lesions of the tongue. On the other hand, an A to G substitution at codon 170 in exon 5 of p53 gene resulting in glutamic acid (ACG) to glycine (GCG) was detected in the DNA of her tongue cancer. These results may suggest that the four lesions have the same origin, and that multi-step oncogenesis had occurred, the APC gene alteration being one of the early events in the process of tumorigenesis and p53 gene alteration involved in the late events.

Modulation of cytoskeletal organization of podocytes during the course of aminonucleoside nephrosis in rats.

By immunoelectron microscopy the modulation of cytoskeletal organization of podocytes during the course of puromycin aminonucleoside-induced nephrosis was examined. In control rats, tubulin and vimentin were present, limited to the podocyte cell body and the major processes. Their distribution in the foot processes was virtually negative. Myosin exhibited the same distribution pattern, albeit much more scattered, with no relation to any podocyte organelles or cell structures. Actin was scattered over the fibrillar zones of the cell body and its processes, including the foot processes. In proteinuric rats, loss of foot processes occurred and the glomerular basement membrane was covered by broad cytoplasmic sheets of podocytes, which contained these four subunits of cytoplasmic filaments. Accompanied by the disappearance of proteinuria, the structural organization of the foot processes was completely restored, in which tubulin, vimentin, and myosin were scarcely observed. Our results confirmed that the loss of foot processes is caused by their retraction, and indicated that the specific localization of the podocytic cytoskeleton contributes to the maintenance of the particular cell shape. Its reorganization may account for the structural modification of podocytes.

Reevaluation of anionic sites in the rat glomerular basement membrane.

We reevaluated the distribution of anionic sites in the glomerular basement membrane with ruthenium red, alcian blue, cationic ferritin, polyethyleneimine, and cationic colloidal gold. Without the accentuation by the metal staining with uranyl acetate and lead citrate, we observed the existence of anionic sites throughout all the layers of the glomerular basement membrane with a similar reticular pattern and the structural difference between the lamina rara and lamina densa, indicating that the lamina rara is an actual structural element.

Ultrastructural organization of the glomerular basement membrane as revealed by a deep-etch replica method.

The fine structure of the glomerular basement membrane was re-evaluated by using a deep-etch replica method. The structure of the laminae rarae interna and externa of the rat glomerular basement membrane was basically identical in that 6 to 8 nm fibrils were interconnected to form a three-dimensional, polygonal network. The size of the mesh was quite variable but most often ranged from 20 to 25 nm in width. In addition, a zipper-like substructure of the epithelial slit diaphragm was observed. By contrast, the lamina densa was composed of closely packed particles. After exposure of the bovine glomerular basement membrane to ultrasonic waves or trypsin, the particles of the lamina densa were effectively removed. The underlying structure showed the fibrillar network closely resembled that seen in the laminae rarae of the rat glomerular basement membrane. The glomerular basement membrane thus revealed was as principally composed of a fibrillar network, which might be regularly arranged units of type-IV collagen. Numerous fine particles, most likely proper components of the glomerular basement membrane, were attached onto this basic fibrillar structure, giving rise to a morphologic appearance different from that of the laminae rarae.

Daunomycin-induced nephropathy in rats.

A single intravenous injection of daunomycin into rats induced severe glomerular injury with massive proteinuria. Mesangial thickening due to an increase in the matrix appeared as early as 5 weeks after injection. Focal and segmental glomerular tuft distortion developed by 10 weeks associated with a progressive mesangial change, which was accompanied by detachments of endothelial cells and podocytes from the glomerular basement membrane (GBM) resulting in obliteration of the affected tufts. After 20 weeks, the lesion ultimately progressed to cause diffuse and global glomerular obliteration. Scattered glomeruli also showed frank shrinkage with a mild obliterative change. By observing a number of isolated glomeruli in scanning electron microscopy, it was revealed that podocyte alterations were variable from case to case and foot processes remained discrete in some cases until 10 weeks, despite the presence of marked proteinuria. Anionic sites distributed throughout the GBM and on the surface of podocytes were usually preserved in proteinuric rats as far as evaluated by ruthenium red and colloidal iron stainings. Our results indicate that loss of foot processes and of glomerular anionic sites are not causative factors but consequences of proteinuria.

[Mixed mesodermal tumor of the ovary].

A 68-year-old woman with a malignant mixed mesodermal tumor of the ovary is reported. Her clinical course worsened rapidly and she died 3 months after admission. At autopsy, the pelvic cavity was seen to be filled with a huge tumor mass. Histologically, the tumor contained malignant epithelial and mesenchymal elements. The epithelial component was an adenosquamous carcinoma. The stromal element was comprised mainly of anaplastic, undifferentiated spindle cells. A variety of malignant mesenchymal elements were also present. They resembled rhabdomyosarcoma, liposarcoma, chondrosarcoma, fibrosarcoma, and myxosarcoma . A review of the Japanese literature concerning this tumor is also presented.

Morphological alterations of glomerulus induced by infusion of cationized ferritin.

Morphological alterations of the glomerulus were induced by infusion of cationized ferritin. After a direct injection of highly cationized ferritin (CF) into the left kidney of rats, endothelial injuries were followed by activation of platelets and the coagulation system after 1-2 h, which occluded capillary loops. In most glomeruli, resolving processes occurred from 2 h onward, leaving a mild thickening of the mesangial region at 7 days. On the other hand, in severely involved glomeruli, capillary loops were still obstructed even at 24 h by hypertrophic and proliferated endothelial cells as well as mesangial cells, instead of platelets and fibrin strands. After this period, exfoliation of podocytes and endothelial cells occurred over a wide area, which resulted in glomerular obsolescence at 7 days. These progressive glomerular injuries were assumed to be closely related to the persistence of CF in glomeruli, which might be caused by disturbances of glomerular clearing systems. Mild proteinuria was only noticed in severely involved cases. It is concluded that an assault on glomerular endothelial cells by cationic macro-molecules can cause thrombotic complications leading to glomerular obsolescence.

A scanning electron microscopic study of crescentic Masugi nephritis in the rabbit.

Crescentic glomerulonephritis was induced in the rabbit with two intravenous injections of goat nephrotoxic serum (NTS). Prominent proliferative glomerulonephritis, characterized by intracapillary as well as extracapillary emigration of monocytes and fibrin deposition, developed 7 days after the first injection. The changes rapidly progressed to crescent formation. In order to observe alterations of the glomerular basement membrane (GBM) related to crescent formation, unfixed, isolated glomeruli were treated with Triton X-100. The GBM thus denuded was shown to have a number of microperforations, which subsequently became much larger holes or fissures. It is suggested that monocytes and fibrin deposits may play a role in the induction of the GBM change.

Combined hepatocellular and mucinous carcinoma.

A rare autopsy case of combined liver cell and bile duct carcinoma (CLBC) occurring in a 51-year-old male with alcoholic liver cirrhosis is presented. Histologically, while the primary lesion was solely composed of well differentiated hepatocellular carcinoma (HCC), intrahepatic metastases consisted of a variable admixture of HCC and cholangiocarcinoma (CC) with excessive mucin production. Interestingly, the tumor cell cluster showing a trabecular growth pattern produced both bile and mucin, thus converting from HCC to mucinous CC. It is concluded that this liver malignancy is principally HCC with a marked tendency to transform into CC. The importance of the findings, especially the simultaneous production of bile and mucin within the same cell cluster, is emphasized in terms of the classification of CLBCs.

Cellular aspects of rabbit Masugi nephritis V. Ultrastructural cytochemistry of monocytic cells.

Ultrastructural cytochemistry for nonspecific esterase (NSE) was performed on normal and nephritic rabbit kidneys. In normal glomeruli distinct reaction deposits appearing as electron-dense granules were present in visceral epithelial cells (podocytes) and epithelial cells of Bowman's capsule, but only a few small or minute deposits were seen in some endothelial and mesangial cells. In acute proliferative glomerulonephritis (Masugi nephritis), many reaction deposits occurred in mononuclear cells accumulating in glomerular tufts which presented the characteristic features of monocytic cells. Macrophages which had migrated into subendothelial space as well as epithelioid cells and multinucleated giant cells, all of which are known to be derived from monocytes, also exhibited the reaction product. The NSE granules in mesangial and endothelial cells were much smaller and fewer in number than those in monocytic cells. The present method may contribute to the more precise differentiation of monocytic cells from mesangial and endothelial cells in proliferative glomerulonephritis.

Carcinosarcoma of the prostate.

A unique case of carcinosarcoma of the prostate occurring in a 32 year old man is presented. This is the youngest case reported to date among nine well-documented examples. The patient underwent a total prostatectomy under the diagnosis of prostatic sarcoma. Despite adjuvant chemotherapy and full-dose radiotherapy being undertaken, the patient died from multiple lung metastases about 8 months after the operation. The surgically resected primary tumor was composed of two histologically distinct elements, these being an undifferentiated carcinoma and a sarcoma with various mesodermal components. These elements were intimately intermingled and transitional forms were often noticed. The sarcomatous portion contained myxoid areas, spindle cell sarcomas with nuclear palisading, areas of osteoid formation and small islands of chondromatous differentiation. The pathogenesis of this complex neoplasm is discussed, and it is suggested that vestigial embryologic Müllerian mesodermal tissue may be capable of diverse differentiation.

Hepatocellular carcinoma with rhabdomyoblastic differentiation.

An extremely unique case of a liver tumor occurring in a 70-year-old man is documented in this article. The primary tumor was well encapsulated by a thick, connective capsule and was histologically composed of two distinct elements, i.e., a common hepatocellular carcinoma (HCC) and a rhabdomyosarcoma. Metastasis of HCC was only seen in the left adrenal gland, whereas intrahepatic metastatic foci as well as tumor thrombi occluding the portal vein branches were composed exclusively of rhabdomyosarcoma. The possibility that the rhabdomyoblastic component might have come from the preexisting HCC by way of metaplastic proliferation is discussed.

Peliosis hepatis. An unusual case involving the spleen and lymph nodes.

A case of peliosis hepatis in a 52-year-old woman with unusual involvement of the spleen and lymph nodes is described. The initial sign was intraperitoneal hemorrhage from the splenic lesion, recessitating splenectomy. The hepatic lesion, which was first noticed during the operation, rapidly progressed and eventually resulted in hepatic rupture with fatal intraperitoneal hemorrhage. Serial sections treated by silver impregnation revealed degeneration and dissolution of the fine reticulin framework in the involved organs, suggesting the possible morphogenesis of the peliotic lesion. The patient had no history of any underlying disorders or of medication with steroids.

Coexistence of adenocarcinoma and choriocarcinoma in the sigmoid colon.

A rare case of a colon carcinoma that developed in a 50-year-old woman is documented. Histologically, the removed tumor was composed of two distinctive elements, i.e., well-differentiated papillary adenocarcinoma and choriocarcinoma. It was strongly suggested that the latter malignancy derived from the pre-existing colonic carcinoma through metaplastic proliferation. A very high human chorionic gonadotropin level was noted in the patient's serum obtained at the preoperative stage. Autopsy materials revealed that metastatic foci in the liver, lungs, and lymph nodes were exclusively composed of choriocarcinoma.

Metastatic malignant meningioma of the liver with hypoglycemia: report of a case.

We herein present the case of a 68-year-old male who suffered an episode of hypoglycemic shock 2 years after undergoing total removal of a bifrontal parasagittal malignant meningioma. Imaging studies revealed three giant hypervascular tumors with a cystic portion in the right lobe, but no confirmed preoperative diagnosis could be made. At laparotomy, liver tumors were found in the medial segment of the left lobe as well as in the right lobe, and thus an extended right lobectomy was performed. All the resected tumors were histologically diagnosed as metastatic malignant meningiomas of the liver. Despite subsequent transarterial chemoembolization for a recurrence in the residual liver, the patient died 11 months after surgery. To the best of our knowledge, only one other case of a hepatectomy for liver metastases from an intracranial malignant meningioma has been reported in the literature, but there has never been any report of surgical treatment for a metastatic meningeal tumor in the liver associated with hypoglycemia. Although our surgical treatment provided effective palliation, the prognostic significance of a surgical strategy for such patients has yet to be established.

Allelic loss of chromosome 13q14.3 in human oral cancer: correlation with lymph node metastasis.

To evaluate the role of chromosome 13 deletions in oral squamous cell carcinoma (SCC) progression and to define the precise localization of putative tumor suppressor genes, we studied tumors from 34 unrelated patients with oral SCC by the polymerase chain reaction (PCR)-loss of heterozygosity (LOH) assay, using 18 different polymorphic loci. Chromosome 13q allelic losses (LOH) were observed in 67.6% at 1 or more loci. These results enabled the identification of a putative minimal region of deletion mapped at 13q14.3. The commonly deleted region is located close, but telomeric to the RB1 locus. We also examined the same samples for inactivation of the RB1 gene by immunohistochemical analysis of paraffin-embedded samples, but no significant variation in RB protein expression was detected. In addition, we also performed PCR-single-strand conformational polymorphism (SSCP) analysis to detect any mutation of the RB1 gene using 52 primer pairs, which covers all exons of this gene. We found no mutations of the RB1 gene in our samples. Interestingly, we found significant correlation between LOH of 13q14.3 and lymph node metastasis. Our results indicate that LOH of 13q is a common event in oncogenesis and/or progression of oral SCC, and also suggest the existence of a new suppressor gene near D13S273-D13S176 loci which may play a role in these events.

Role of neutrophils in sinusoidal endothelial cell injury after extensive hepatectomy in cholestatic rats.

BACKGROUND AND AIMS: The authors have shown previously that sinusoidal endothelial cell injury developed concomitantly with the accumulation of neutrophils in the hepatic sinusoidal space in cholestatic rats after extensive hepatectomy. The aim of the present study was to investigate the role of neutrophils in the development of this kind of endothelial cell injury. METHODS: Rats underwent 78% partial hepatectomy after 2 weeks of cholestasis, and subsequent external biliary drainage for 5 days. To decrease the number of neutrophils, antirat neutrophil serum was administered intraperitoneally. Some serum parameters and histological specimens were examined 48 h after partial hepatectomy. RESULTS: Anti-neutrophil serum significantly reduced the number of accumulated neutrophils in the hepatic sinusoids. Although the purine nucleoside phosphorylase: alanine aminotransferase ratio, a marker of non-parenchymal cell injury, was increased in cholestatic-hepatectomized rats, this abnormality was significantly attenuated by the treatment with antineutrophil serum. Electron microscopically, focal detachment of cytoplasms of sinusoidal endothelial cells was observed occasionally in cholestatic-hepatectomized rats, but was not found in the antirat neutrophil serum-treated rats. CONCLUSION: These results indicate that accumulated neutrophils might be important effector cells in the pathogenesis of sinusoidal endothelial cell injury after extensive hepatectomy in cholestatic rats, even after appropriate external biliary drainage.