Renal involvement induced by human parvovirus B19 infection

In an attempt to clarify the renal involvement induced by human parvovirus B19 (HPB19) infection, we investigated 6 adult patients with transient urinary abnormalities followed by erythema infectiosum. All patients had HPB19-specific IgM antibody and showed mild proteinuria of 0.2-1.2 g/day with or without microscopic hematuria. In 5 patients a decrease of complement was present, and in 2 the circulating immune complex levels were elevated. All patients showed mild or moderate endocapillary proliferation with leukocytic infiltrates in glomeruli and leukocytic infiltrates with edema around interlobular arteries and arterioles. Immunofluorescence microscopy revealed C3c deposits with immunoglobulins along the glomerular capillary walls and in the walls of small arteries and arterioles. Electron microscopic studies showed swelling of the endothelial cells and small electron-dense deposits in mesangium (in all 6 patients) and subendothelium (in 5 of 6 patients). However, HPB19 VP1 and VP2 capsid antigens were not demonstrated in the glomerulus or the vascular wall in any patient. These findings suggest that the renal lesions caused by an immune complex mediated phenomenon would be closely correlated with the HPB19 infection, although the precise mechanism is not entirely clear, and that in adults HPB19 should be thought of as a possible cause of acute postinfectious glomerulonephritis.

Secretory meningioma with lipomatous component: case report

A case of meningioma coexisting with both lipomatous and secretory components, the latter characterized by hyaline inclusion bodies, is reported. The neuroradiological features of lipomeningioma are reevaluated, and the possible pathogenetic mechanisms of this unique combination in the present case are discussed.

Malignant transformation of an intrathoracic neurofibroma in von Recklinghausen's disease

Malignant transformation of a mediastinal neurofibroma, presenting for many years as a mass in the superior mediastinum and arising from the right vagus nerve, was found in a patient with long-standing von Recklinghausen's disease. Surgical management of intrathoracic neurogenic tumours, even if clinically benign, is advocated.

Dose-dependent effects of dichloropropanol on liver histology and lipid peroxidation in rats

A rare outbreak of acute hepatic damage in workers exposed to dichloropropanols (DCPs) was reported recently. The purpose of the present study is to examine the effects of DCPs on various organs, the dose dependency and the pathogenetic potential of DCP hepatotoxicity. A single intraperitoneal injection was given to six groups of rats with 0.2 ml of 20% ethanol (control), or 1/8 x, 1/4 x, 1/2 x, 1 x, and 2 x LD50 (0.11 ml/kg) of 1,3-dichloro, 2-propanol (DC2P) diluted in 20% ethanol. After blood samplings, all organs were subjected to histologic examinations with light and electron microscopes. Fresh liver tissues from further 4 control and 4 experimental rats sacrificed 6 hours after the injection of 20% ethanol and 1 x LD50 of DC2P were homogenized and subjected to evaluate lipid peroxidation, glutathione S-transferase activity and reduced glutathione contents in the liver. The rats administered with only ethanol or 1/8 and 1/4 LD50 of DC2P showed no serological or histopathological abnormalities. Marked elevation of serum glutamate pyruvate transaminase (SGPT) with a diffuse massive necrosis of the liver cells were noted in all rats of both the 1 x and 2 x LD50 groups, and irregular zonal necroses were found in 3 of 4 rats injected with 1/2 LD50. There were no serious toxic changes in other organs. Hepatic malondialdehyde level was significantly increased, associated with decreases of liver glutathione S-transferase activity and reduced glutathione content. It was concluded that the serious DC2P-toxicity was mainly found in the livers, dose dependently, and one of the causative mechanisms of this hepatotoxicity might be the lipid peroxidation.

Light chain deposition disease detected by antisera to a variable region of the kappa1 light chain subgroup

A 59-year-old male started maintenance hemodialysis, and 80 months later died of congestive heart failure. Just before death he had no urine, and no monoclonal immunoglobulin could be demonstrated in the serum on immunoelectrophoresis. An autopsy showed deposition of periodic acid-Schiff-positive and Congo red-negative material in the interstitium and vessel walls of almost all organs and tissues. In the glomeruli there was a multifocal nodular accumulation of the material. Electron microscopy showed finely granular, not fibrillar deposits. In spite of these impressive lesions on light microscopy, the material was not stained with commercially available antisera to light chains. However, the material was positive for antisera to the variable region of the kappa1 light chain subgroup. This is the first case with light chain deposition disease that showed positive staining only with antisera to the variable region of the light chain.

Case report: mucin-producing cystic neoplasm of the pancreas with onset in childhood

Mucin-producing tumours of the pancreas have been recently reported with increasing frequency and most cases have occurred in middle-aged and elderly people. In the present report, a case of a 21-year-old man with mucinous cystadenoma of the pancreas is reported. He had a long history of recurrent pancreatitis from the age of 8. When he was aged 10, the first branch of the main pancreatic duct was shown to be enlarged on endoscopic retrograde pancreaticography (ERP). A series of ERP studies and computed tomography scans performed over a period of 11 years demonstrated continuing growth of this enlargement of the pancreatic duct. Pancreaticoduodenectomy was performed and the patient has been well without further episodes of acute pancreatitis and has been free of recurrent tumour for 1 year.

Morphological study of experimental syringomyelia with kaolin-induced hydrocephalus in a canine model

In this morphological study the authors investigated whether spinal cord cavitation, produced in young mongrel dogs that had been rendered hydrocephalic by cisternal injection of kaolin, consists of a dilated central canal or intramedullary cavities. Hydrocephalus was noted in 50 of 56 dogs treated with kaolin. Of the 50 hydrocephalic young dogs, 29 were shown to have central canal dilation that was prominent at the thoracic level and 21 to have cervical intramedullary cavities in the posterior column and/or the posterior horn. In 11 dogs from the latter group these cavities were demonstrated to have no communication with the central canal. This finding could not be explained by the hydrodynamic theory. On histopathological examination, myelomalacia and hemorrhagic infarction following ventricular shunting were noted adjacent to the cervical cavities, which suggested vascular impairment. A perfusion study revealed insufficient blood flow within the cervical cord at the level of the intramedullary cavities. A close correlation between the vascular insufficiency of the cervical cord and the pressure cone resulting from significant hydrocephalus was observed. The latter may cause cervicomedullary compression at the foramen magnum, affecting the venous drainage of the cervical cord below that level, resulting in intramedullary cavitation. Accordingly, vascular impairment was thought to play a significant role in the development of cervical syrinx formation in our kaolin model. The current results may provide a reasonable explanation for the formation of noncommunicating cervical syringomyelia in Chiari I malformation.

Embryonal craniopharyngioma. Case report of the morphogenesis of a craniopharyngioma

BACKGROUND

Ordinary craniopharyngiomas affecting sellar regions of children and preadolescents are composed of ameloblastomatous and/or squamous constituents. The authors encountered an autopsy case of a stillborn infant with a large craniopharyngioma with unusual manifestations.

METHODS

The craniopharyngioma was analyzed using detailed histologic and immunohistochemical techniques.

RESULTS

An autopsy revealed a large tumor arising from the pituitary gland with associated severe hydrocephalus. Histologically, the cells of the tumor showed features of ameloblastoma and organoid structures simulating tooth buds and adenohypophyseal primordia in the stage of organogenesis. Cells of the latter were shown to be immunoreactive for chromogranin A and six adenohypophyseal hormones.

CONCLUSIONS

Because embryology of the adenohypophysis and the teeth indicated that all of the epithelia in this tumor emerged during the normal development of the stomodeum, it was believed that an "embryonal form of craniopharyngioma" would characterize this organoid neoplasm best. The possible morphogenesis of craniopharyngioma is also discussed.

Autopsy findings of Addison's disease caused by systemic cytomegalovirus infection in a patient with acquired immunodeficiency syndrome

We previously reported a case of Addison's disease associated with acquired immunodeficiency syndrome (AIDS) (Endocr J, 41:13, 1994). A 46-year-old man with hemophilia B and AIDS was diagnosed as Addison's disease. The positive cytomegalovirus (CMV) antigen in urine suggested that CMV adrenalitis may have caused the adrenal insufficiency. Despite treatment with ganciclovir, the patient died one year later. Autopsy findings revealed that the typical inclusions of CMV were seen in the lung, adrenal glands (both cortex and medulla) and small intestine. Here, we describe the subsequent clinical course and postmortem findings of this case.

Alterations in bile ducts and peribiliary microcirculation in rats after common bile duct ligation

The chronological changes in ductular epithelium and peribiliary capillary plexuses (PBPs) after bile duct ligation are not well understood. Therefore, we examined alterations in both intrahepatic bile ductules and peribiliary microcirculation in rats after ligation of the common bile duct using immunohistochemistry, transmission electron microscopes (TEM), and scanning electron microscopes (SEM). Ductular proliferations appeared first in the peripheral areas of the portal spaces and then gradually advanced along with increasing jaundice. Distorted configuration of the hepatic parenchyma with interconnecting stroma rich in irregular ductules developed 4 weeks after the ligation. Numerous biliary cell types and cells of types intermediate between hepatocytes and biliary cells together with poorly fenestrated capillary-type vessels appeared in the periportal parenchyma, in association with an increased number of canalicular-ductular junctions on TEM. These biliary cells were often found within the lobules and apart from the stroma. SEM examination of hepatic microvascular casts using methacrylated resin showed formation of irregular portal and periportal capillary networks, partly derived from coarsened sinusoids. Direct connections between the newly formed capillary networks and the pre-existing PBPs or sinusoids were numerous, although there were few direct connections between the capillary networks and the hepatic arterial branches. Thus, these proliferated ductules and newly formed complicated capillary networks might play an important role in the effective transport of biliary materials between hepatocytes and native bile ducts or proliferated ductules through the altered microcirculation after bile duct ligation.

Alterations in bile ducts and peribiliary microcirculation in rats after common bile duct ligation

The chronological changes in ductular epithelium and peribiliary capillary plexuses (PBPs) after bile duct ligation are not well understood. Therefore, we examined alterations in both intrahepatic bile ductules and peribiliary microcirculation in rats after ligation of the common bile duct using immunohistochemistry, transmission electron microscopes (TEM), and scanning electron microscopes (SEM). Ductular proliferations appeared first in the peripheral areas of the portal spaces and then gradually advanced along with increasing jaundice. Distorted configuration of the hepatic parenchyma with interconnecting stroma rich in irregular ductules developed 4 weeks after the ligation. Numerous biliary cell types and cells of types intermediate between hepatocytes and biliary cells together with poorly fenestrated capillary-type vessels appeared in the periportal parenchyma, in association with an increased number of canalicular-ductular junctions on TEM. These biliary cells were often found within the lobules and apart from the stroma. SEM examination of hepatic microvascular casts using methacrylated resin showed formation of irregular portal and periportal capillary networks, partly derived from coarsened sinusoids. Direct connections between the newly formed capillary networks and the pre-existing PBPs or sinusoids were numerous, although there were few direct connections between the capillary networks and the hepatic arterial branches. Thus, these proliferated ductules and newly formed complicated capillary networks might play an important role in the effective transport of biliary materials between hepatocytes and native bile ducts or proliferated ductules through the altered microcirculation after bile duct ligation.

An immunohistochemical analysis of 13 cases with combined hepatocellular and cholangiocellular carcinoma

Thirteen cases of combined hepatocellular (HCC) and cholangiocellular carcinoma (CCC) were examined. In addition to routine pathology, immunoreactivities for carcinoembryonic antigen, alpha-fetoprotein (AFP), cytokeratin (Cam 5.2 and AE1), epithelial membrane antigen (EMA) and tumor-associated glycoprotein 72 (B72.3) were also examined. The average age of the 13 cases was 64.8 years, which lay between the average ages of pure HCC and CCC cases. They were categorized as separate type (2), collision type (6), and intermingled type (5). AE1 and EMA were the best markers to differentiate the CCC from the HCC area. B72.3 immunoreactivity was detected only in CCC (46%). There were no transitional features between HCC and CCC in two cases of the separate type and two cases of the collision type. However, focal transitional features from HCC to CCC were observed in all cases of the intermingled type and in four of six cases of the collision type. In one case of the intermingled type, many cancer cells contained both bile and mucus simultaneously, and revealed dual immunoreactivities. The conclusions are: 1) the combined type is generated from two sources; one is the intrahepatic double cancer (thoroughly separate type and a part of the collision type) and another is the stem cell origin with diverse phenotypes (intermingled type and a part of the collision tumor); and 2) AE1 was the most helpful marker to differentiate the CCC area from HCC, and other markers, e.g. AFP for HCC and EMA, CEA, and B72.3 for CCC, were also supportive but somewhat limited in the differential diagnosis.

Biological effects of inhaled magnesium sulphate whiskers in rats

Male Wistar rats were exposed to two types of magnesium sulphate whiskers by inhalation for six hours a day, five days a week, for four weeks (sub-chronic study), or for one year (chronic study) to clarify the biological effects of the whiskers. There were few whiskers detected in the rat lungs even at one day after the exposure, suggesting that they are dissolved and eliminated rapidly from the lungs. To measure the clearance rate of the whiskers from the lungs, an intratracheal instillation was performed in golden hamsters. The half life of the whiskers in the lung was determined as 17.6 minutes by temporally measuring the magnesium concentration up to 80 minutes after the instillation. A histopathological examination indicated a frequent occurrence of adenoma and carcinoma in the year after chronic exposure, but it was not significantly different between exposed and control rats.

Small bile duct abnormalities and chronic intrahepatic cholestasis in Behçet's syndrome

A 42-year-old man with Behçet's disease of the intestinal type and a chronic cholestatic profile is presented. He had oral aphthea, genital ulcer, erythema nodosum, thrombophlebitis and central retinitis during the clinical course. Deep ileal ulcers recurred with massive bleeding and perforation. Cholestatic laboratory findings were also noted in the clinical course. A biopsied liver specimen, taken at the second operation for the ileal ulcer, showed chronic portal inflammation associated with ductopenia and epithelial degeneration of the small interlobular bile ducts, but periductal concentric fibrosis was not found. The patient died of sepsis 7 months after the last laparotomy. Although there was no significant abnormality in the large biliary tract at autopsy, pericholangitis in the small portal tracts and cholestasis were pronounced. Sclerosing cholangitis is one of well-known complications of ulcerative colitis or Crohn's disease. We report herein another rare association of small bile duct damage resembling sclerosing cholangitis with enteritis in Behçet's disease.

Immunohistochemical and ultrastructural study of hepatic sinusoidal linings during dichloropropanol-induced acute hepatic necrosis

An acute phase of severe hepatic necrosis induced by dichloropropanol was examined immunohistochemically and ultrastructurally, in order to study chronological changes of sinusoidal morphology during acute hepatic injury. Male Wistar rats were injected with 1,3-dichloro-2-propanol (DC2P) and sacrificed at various intervals after the injections. DC2P-injected rats showed zonal necrosis of the centrilobular space with a peak from 24 to 48 h after the injection. Destruction of sinusoidal linings appeared at 4 h, and was gradually aggravated along the advancing hepatocytic necrosis. Monocytic influx into the necrotic areas was initiated at 6 h. At 48 h, collapsed centrilobular spaces showed a loss of most sinusoidal structures with active phagocytosis of macrophages, proliferation of perisinusoidal cells, and accumulation of collagen fibrils. At 72 h, there were many regenerating sinusoidal structures, which were composed of rather thick and less fenestrated endothelium and underlying multilayered processes of mesenchymal cells, along the regenerating hepatocytes. In these areas, occasional junctions between regenerating hepatocytes and mesenchymal cells were seen. Reconstruction of sinusoidal linings was closely related to the hepatocytic regeneration, and a hepatocytic-mesenchymal interaction might participate in this morphodynamic course of the sinusoidal reconstruction.

Investigation of resected multinodular hepatocellular carcinoma: assessment of unicentric or multicentric genesis from histological and prognostic viewpoint

OBJECTIVES

Multicentricity of hepatocellular carcinoma (HCC) is attracting a great deal of attention at present. However, few studies have focused on the prognostic comparison between unicentric and multicentric multinodular HCCs. The aim of this study is the reevaluation of histologic criteria of multicentric HCC and a prognostic comparison between the two groups mentioned above.

METHODS

Forty-nine cases with intrahepatic multiple nodules of HCC, by gross examination, among 184 consecutive resected HCCs were examined clinicopathologically. These cases were divided into three groups: group A, cases suggestive of multicentric genesis; group B, unicentric cases; and group C, indeterminate cases. Histopathological characteristics and the cumulative survival rates were compared among these groups.

RESULTS

Five cases were categorized as group A, 36 cases as group B, and eight cases as group C. Nodules in group A were smaller than 2 cm in diameter, situated discretely and well differentiated, and with neither vascular nor capsular invasion. Most of the nodules lacked a tumor capsule and had an irregular border. In the 36 cases of group B, all main tumors had vascular and/or capsular invasion. The cellularity index was almost the same in all groups. The cumulative survival rate of group A was better than that of group B or group C.

CONCLUSIONS

Small multiple nodules of well-differentiated hepatocellular carcinoma without vascular and capsular invasion might be multicentric, and these early detections and operations could result in a fairly good prognosis, despite the multiple HCC nodules.

Predictable factors for estimating prognosis of patients after resection of hepatocellular carcinoma

BACKGROUND

Although many studies have been concerned with a clarification of the relation between various clinicopathologic factors and the prognosis of operated hepatocellular carcinoma (HCC), few studies have focused on the prognostic predictability of mitotic index and anti-hepatitis C virus (anti-HCV).

METHODS

One hundred forty cases of HCC with hepatic resection were observed from 1 to 11 years, and the relationship among various clinicopathologic factors, including the mitotic index and anti-HCV, and prognosis was evaluated.

RESULTS

Age at the time of operation, positive results for hepatitis B surface antigen or anti-HCV, accompanying cirrhosis, and the degree of tumor necrosis due to transarterial embolization did not influence the prognosis significantly. Patients with hepatitis C virus-related cases had a better prognosis than patients with hepatitis B-related cases. Patients with a single and small carcinoma smaller than 2 cm had a significantly better prognosis than those who had larger and/or multiple tumors. A better prognosis also was observed in the carcinomas with no histologic invasion into portal vein branches, low Edmondson grades, and low mitotic activities when compared with the counterpart of each group. Among these factors, the mitotic index was correlated best with prognosis in the current study.

CONCLUSIONS

The examination of mitotic index was quite simple, and the index was a helpful factor in predicting prognosis.

Predictable factors for estimating prognosis of patients after resection of hepatocellular carcinoma

BACKGROUND

Although many studies have been concerned with a clarification of the relation between various clinicopathologic factors and the prognosis of operated hepatocellular carcinoma (HCC), few studies have focused on the prognostic predictability of mitotic index and anti-hepatitis C virus (anti-HCV).

METHODS

One hundred forty cases of HCC with hepatic resection were observed from 1 to 11 years, and the relationship among various clinicopathologic factors, including the mitotic index and anti-HCV, and prognosis was evaluated.

RESULTS

Age at the time of operation, positive results for hepatitis B surface antigen or anti-HCV, accompanying cirrhosis, and the degree of tumor necrosis due to transarterial embolization did not influence the prognosis significantly. Patients with hepatitis C virus-related cases had a better prognosis than patients with hepatitis B-related cases. Patients with a single and small carcinoma smaller than 2 cm had a significantly better prognosis than those who had larger and/or multiple tumors. A better prognosis also was observed in the carcinomas with no histologic invasion into portal vein branches, low Edmondson grades, and low mitotic activities when compared with the counterpart of each group. Among these factors, the mitotic index was correlated best with prognosis in the current study.

CONCLUSIONS

The examination of mitotic index was quite simple, and the index was a helpful factor in predicting prognosis.

Predictable factors for estimating prognosis of patients after resection of hepatocellular carcinoma

BACKGROUND

Although many studies have been concerned with a clarification of the relation between various clinicopathologic factors and the prognosis of operated hepatocellular carcinoma (HCC), few studies have focused on the prognostic predictability of mitotic index and anti-hepatitis C virus (anti-HCV).

METHODS

One hundred forty cases of HCC with hepatic resection were observed from 1 to 11 years, and the relationship among various clinicopathologic factors, including the mitotic index and anti-HCV, and prognosis was evaluated.

RESULTS

Age at the time of operation, positive results for hepatitis B surface antigen or anti-HCV, accompanying cirrhosis, and the degree of tumor necrosis due to transarterial embolization did not influence the prognosis significantly. Patients with hepatitis C virus-related cases had a better prognosis than patients with hepatitis B-related cases. Patients with a single and small carcinoma smaller than 2 cm had a significantly better prognosis than those who had larger and/or multiple tumors. A better prognosis also was observed in the carcinomas with no histologic invasion into portal vein branches, low Edmondson grades, and low mitotic activities when compared with the counterpart of each group. Among these factors, the mitotic index was correlated best with prognosis in the current study.

CONCLUSIONS

The examination of mitotic index was quite simple, and the index was a helpful factor in predicting prognosis.

A unique case of apocrine carcinoma on the male pubic skin: histopathologic and ultrastructural observations

We report a case of cutaneous adenocarcinoma on the pubic region of a 56-year-old male. The exophytic tumor showed solid, ductal, and glandular patterns with decapitation secretion and mucinous carcinoma-like nests. Despite the exophytic nature of the lesion, an invasive growth pattern into the deep dermis and subcutaneous fat was seen. An additional characteristic of this tumor was the presence of Paget's phenomenon. From these findings, we conclude that this tumor is an apocrine adenocarcinoma having an unusual clinical appearance and unique histopathological features which have some similarities to apocrine carcinoma of the breast and some to syringocystadenoma papilliferum and nipple adenomatosis.

Pancreatic morphogenesis and extracellular matrix organization during rat development

We investigated the rat pancreatic morphology at various developmental stages ranging from 12 days of gestation to the neonatal stage, with special emphasis on alterations in extracellular matrix organization in vivo. The rat pancreatic development in utero could be divided into four representative stages as follows: (1) initial epithelial buds (12 days of gestation), (2) elongated and branching epithelium (13-14 days), (3) tubular structure (15-16 days), and (4) acinar structure (17 days or more). Ultrastructurally, the fetal and neonatal pancreata were almost constantly encompassed by continuous basal lamina, except for the earliest stage, in which minute disruptions of basal lamina were observed. Through the disruption, the direct epithelial-mesenchymal contact was formed between an endocrine cell and an adjacent mesenchymal cell, which implied epithelial-mesenchymal interactions in processes of endocrine cell differentiation. Collagen fibrils were frequently accumulated at the cleft (branchpoint) of the branching epithelium during the second and third stages mentioned above. Immunohistochemically, fibronectin and collagen type-I were localized particularly beside the neck (narrow part) or cleft of the pancreatic epithelium at these stages, although continuous linear localization of these matrices was noted around the initial pancreatic bud. This was in contrast to invariable linear localization of laminin and collagen type-IV at the epithelial/mesenchymal interface throughout the pancreatic development. Diffuse fibrillar localization of fibronectin and collagen type-I in the mesenchyme was pronounced at the later stages and after birth. Collagen type-III was only focally detectable around the pancreatic epithelium from the second stage, and its distinct localization was noted in the interlobular connective tissue after birth. Thus, chronological changes in extracellular matrix organization seemed to be closely related to morphogenetic processes of the rat pancreas, especially in the branching epithelial morphogenesis, and the major alterations appeared prior to distinct acinar cell differentiation.

Appearance of pulmonary metastases on high-resolution CT scans: comparison with histopathologic findings from autopsy specimens

OBJECTIVE

The purpose of this study was to compare the appearance of pulmonary metastases on high-resolution CT scans with the histopathologic findings in lung specimens obtained at autopsy. The factors considered were the appearance of the margins of pulmonary metastases, the location of relatively small nodules in relation to the secondary pulmonary lobules, and the detectability of lymphangitic spread of tumors and intravascular tumor emboli on high-resolution CT scans.

MATERIALS AND METHODS

We studied 14 lungs obtained at autopsy that contained metastatic lesions. We used both microscopy and high-resolution CT to evaluate 87 metastatic nodules 5-20 mm in diameter for the appearance of their margins and to determine the location of 43 nodules that were less than 5 mm in diameter relative to the secondary pulmonary lobules. The detection of histologically confirmed intravascular tumor emboli and lymphangitic spread by high-resolution CT also was evaluated.

RESULTS

On high-resolution CT scans, 38% of the nodules had well-defined, smooth margins, 16% had well-defined, irregular margins, 16% had poorly defined, smooth margins, and 30% had poorly defined, irregular margins. The well-defined, smooth margins on high-resolution CT scans corresponded histologically to an expanding type and to an alveolar space-filling type; the poorly defined margins, to an alveolar cell type; and the irregular margins, to an interstitial proliferative type. Some correlation was found between the histologic type of primary tumor and the CT appearance of the lesion's margins. As for small nodules, 12% were connected with the central bronchovascular bundle, 28% were on the perilobular structures, and 60% were apparently not in contact with these structures. Only two of the 11 lungs with histopathologically confirmed lymphangitic tumor spread and none of the tumor emboli were detected on high-resolution CT scans.

CONCLUSION

The characteristics of the margins of metastatic pulmonary nodules noted on histopathologic examination correlated well with their high-resolution CT findings. Microscopic intravascular tumor emboli and lymphangitic tumor spread were difficult to detect on high-resolution CT scans, indicating a limitation of high-resolution CT in the diagnosis of pulmonary metastatic disease.

Submassive hepatic necrosis induced by dichloropropanol

A hitherto undescribed industrial liver injury of fulminant form induced by dichloropropanol is reported. Two middle-aged men developed severe hepatic injury just after cleaning a dichloropropanol tank at a plant producing dichloropropanol. They died from hepatic failure 4 and 11 days respectively, after carrying out the work. Liver specimens taken at autopsy from one of the cases showed submassive hepatic necrosis. This accident prompted us to undertake an experimental study in rats of intraperitoneal one-shot injection of two isomeric substances of dichloropropanol, that is, 2,3-dichloro-1-propanol (DC1P) and 1,3-dichloro-2-propanol (DC2P). Saline was injected into the control rats. One, two, four, six, 24, 48, 72 h, and 1 week after the injection, rats in each group were sacrificed. Neither control nor DC1P-injected rats showed significant biochemical or histopathological abnormalities. DC2P-injected rats revealed elevations of transaminase from 6 h after the injections, and submassive necrosis of the liver was observed in many rats. It was concluded that the severe liver injuries in both the human cases and rats in our study were caused by DC2P.

Pancreatic islet abnormalities in sudden infant death syndrome. Qualitative and quantitative analyses of 15 cases

The pancreata of 15 autopsy cases of sudden infant death syndrome (SIDS) and those of 14 age-matched controls were examined qualitatively and quantitatively to re-evaluate the relationship between pancreatic islet abnormalities and sudden death in infancy. Histopathologically, a diffuse or focal form of nesidioblastosis and septal islets were frequently observed in the pancreata of both groups. Endocrine cell dysplasia was found only in 2 infants who had died of SIDS. Quantitatively, there was little difference of islet cell composition between the SIDS cases and the controls. A relatively high proportion of islet cell area to total pancreatic tissue area was demonstrated in the SIDS group (8.46 +/- 4.90% in the pancreatic head; 8.66 +/- 4.23% in the pancreatic body to tail) in comparison with the controls (5.32 +/- 1.77%; 5.63 +/- 1.60%). Although nesidioblastosis and septal islets were considered to be within the limits of normal variation during pancreatic development, endocrine cell dysplasia and quantitatively unusual proliferation of the pancreatic endocrine tissue suggest the possibility that abnormalities in the endocrine pancreas may be causally related to sudden death in infancy.

[Sarcomatoid liver carcinoma diagnosed clinically as hemangioma]

This is a case report of a 69-year-old woman with sarcomatoid hepatocellular carcinoma (HCC), which was diagnosed clinically as hemangioma. She was first admitted to our university hospital, complaining of general fatigue in December, 1988, and cholelithiasis and liver cirrhosis with hepatic tumor in Segment 8 were diagnosed. The serum AFP level was within normal range, and the tumor was diagnosed as hemangioma radiologically. She underwent only cholecystectomy and was well without any therapy for the liver tumor up until March in 1991 when she was readmitted to our university hospital due to rapidly progressive liver dysfunction. The size of the liver tumor was unchanged. Despite intensive care, she died of hepatic failure due to cirrhosis in a decompensation state. At autopsy, a well defined yellowish white tumor of 3 cm in maximum diameter was seen in the cirrhotic liver. Although the largest part of the tumor revealed necrosis and hyalinization, a sarcomatoid part composed of spindle-shaped cells was noted in the peripheral portion. In addition, some necrotic ghost cells, probably hepatocellular carcinoma, were also noted. Low molecular cytokeratin, which is always found in HCCs, was seen in spindle-shaped sarcomatoid cells. The liver tumor was diagnosed as sarcomatoid HCC from these pathological findings. We report this histologically unusual HCC with an immunohistochemical study.

Antihepatitis C virus status in hepatocellular carcinoma and the influence on clinicopathological findings and operative results

Antihepatitis C virus (HCV) status was investigated in 100 patients undergoing hepatectomy for hepatocellular carcinoma (HCC) between 1980 and 1989. The clinicopathological findings and operative results, in patients with or without HCV marker, were compared retrospectively. The positivity rate of anti-HCV was 51 per cent. In this group there was a higher mean age, fewer symptoms, raised alanine aminotransferase level, higher 15-min indocyanine green clearance rate and earlier tumour stage compared with the anti-HCV negative group. Positive tumour margins and vascular invasion were seen less frequently in the anti-HCV positive group. HCC with HCV marker showed characteristic features of chronic non-A non-B hepatitis and of HCC originating from liver cirrhosis. There was a better cumulative 1-year survival rate for anti-HCV positive patients, but 3- and 5-year survival rates after hepatectomy were similar in both groups. Although HCV-related HCC had typical features of chronic non-A non-B hepatitis and a relatively early stage of tumour, biological features and operative results were similar with or without the HCV marker.

A histopathological and ultrastructural study of eccrine porocarcinoma with special reference to its subtypes

Five cases of eccrine porocarcinoma were studied by light and electron microscopy. Histopathologically, these could be classified into two types; the common and the giant cell type. The common type was characterized by almost uniform medium-sized cuboidal tumour cells and a formation of well-developed intracytoplasmic lumina. A broad diversity of histopathological and ultrastructural features was seen in these tumours. The tumours of the giant cell type consisted of mononuclear polygonal cells and bizarre giant cells. This type was considered to be an undifferentiated form of porocarcinoma.

Hepatic lymphangiomatosis: report of two cases, with an immunohistochemical study

Two cases of hepatic lymphangiomatosis were examined. One tumor was noted incidentally at autopsy, and the other tumor was removed by operation. These liver tumors could not be detected by the naked eye, but ill-defined lace-like areas were seen. Microscopically, small cystic spaces were irregularly aggregated in the hepatic parenchyma and, in part, in the portal tracts. Faintly stained lymph-like material without any erythrocytes was found in the spaces. The silver impregnation method confirmed that most of the cystic lumina were dilated Disse's spaces. Also, some of them were directly connected with lymph vessels in the portal tracts. Thin lining cells along the internal surface of these cystic channels could not be positively stained by Ulex europaens 1 or factor 8-related antigen, both of which were present in the endothelium of the blood vessels in the portal tracts. We describe herein this rare lymphangiomatosis of the liver, with special reference to its immunohistochemistry.

Giant cell tumor-like cholangiocarcinoma associated with systemic cholelithiasis

A cholangiocarcinoma of the hepatic hilus with an element of giant cell tumor that occurred in a 59-year-old man is reported. His medical history included systemic cholelithiasis and repeated operations on the biliary passages. Four years after the last operation, which was a hepatic segmentectomy, he was readmitted because of persistent fever. A computed tomography scan showed a low-density area and stones in the hepatic hilus. He died of hepatic failure approximately 1 month later. At autopsy, a fist-sized tumor and gallstones were found at the hepatic hilus. Histologically, the tumor mainly showed sarcomatoid features and some tubular adenocarcinoma. An element of giant cell tumor consisting of many osteoclast-type giant cells also was noted. The results of immunohistochemical studies showed a positive reaction to cytokeratin and vimentin in some of the spindle-shaped sarcomatoid cells. Sarcomatoid bile duct carcinomas are rare, as are those with osteoclast-type giant cells. The authors also discuss the histogenesis of these giant cells.

Giant cell tumor-like cholangiocarcinoma associated with systemic cholelithiasis

A cholangiocarcinoma of the hepatic hilus with an element of giant cell tumor that occurred in a 59-year-old man is reported. His medical history included systemic cholelithiasis and repeated operations on the biliary passages. Four years after the last operation, which was a hepatic segmentectomy, he was readmitted because of persistent fever. A computed tomography scan showed a low-density area and stones in the hepatic hilus. He died of hepatic failure approximately 1 month later. At autopsy, a fist-sized tumor and gallstones were found at the hepatic hilus. Histologically, the tumor mainly showed sarcomatoid features and some tubular adenocarcinoma. An element of giant cell tumor consisting of many osteoclast-type giant cells also was noted. The results of immunohistochemical studies showed a positive reaction to cytokeratin and vimentin in some of the spindle-shaped sarcomatoid cells. Sarcomatoid bile duct carcinomas are rare, as are those with osteoclast-type giant cells. The authors also discuss the histogenesis of these giant cells.

Giant cell tumor-like cholangiocarcinoma associated with systemic cholelithiasis

A cholangiocarcinoma of the hepatic hilus with an element of giant cell tumor that occurred in a 59-year-old man is reported. His medical history included systemic cholelithiasis and repeated operations on the biliary passages. Four years after the last operation, which was a hepatic segmentectomy, he was readmitted because of persistent fever. A computed tomography scan showed a low-density area and stones in the hepatic hilus. He died of hepatic failure approximately 1 month later. At autopsy, a fist-sized tumor and gallstones were found at the hepatic hilus. Histologically, the tumor mainly showed sarcomatoid features and some tubular adenocarcinoma. An element of giant cell tumor consisting of many osteoclast-type giant cells also was noted. The results of immunohistochemical studies showed a positive reaction to cytokeratin and vimentin in some of the spindle-shaped sarcomatoid cells. Sarcomatoid bile duct carcinomas are rare, as are those with osteoclast-type giant cells. The authors also discuss the histogenesis of these giant cells.

Gastric small cell carcinoma with squamous and neuroendocrine differentiation

A rare gastric carcinoma containing diverse components, that is, neuroendocrine (small cell carcinoma), squamous and gland-like elements in an 82 yr old woman is described. Radiologic examination revealed a large ulcerated tumor, and a Borrmann type II tumor, 6.5 x 5 cm, was found in the resected stomach. Histologically, the tumor was mainly composed of small cells with hyperchromatic nuclei and scant cytoplasm. Argyrophilic granules were seen in these cells. There were also scattered foci of large cells with features of squamous cells, and many intermediate cells with oncocytic cytoplasm. The small cancer cells were positive for chromogranin A and neuron specific enolase. Squamous cell nests were positive for high molecular cytokeratin (CK), and intermediate cells were positive for low molecular CK. Electron microscopic examination revealed secretory granules in the small cells and tonofilaments in the squamous cells. This tumor might have originated from the pluripotential stem cell in the gastric epithelium.

Clinicopathological and immunohistochemical study of basal cell carcinoma with reference to the features of basement membrane

One hundred and thirty-five cases of basal cell carcinoma (BCC) were investigated, focusing upon factors determining a postoperative prognosis. Out of the 135, nine tumors on the face recurred. All of these nine tumors were insufficiently extirpated at the initial operation, and showed micronodular or infiltrative patterns with stromal fibrosis. Dividing the degree of dermal invasion into four levels, all tumors with recurrence reached levels 3 and 4, the two deeper groups. The immunohistochemical study using anti-laminin and anti-type IV collagen antibodies showed various changes of staining pattern around tumor cell nests, such as attenuation, disruption, and thickening of basement membrane, in contrast with the normal thinly continuous staining around nontumorous control epidermis. The disruption of basement membranes was remarkable around the tumor cells showing a micronodular growth pattern, although the discontinuity of basement membrane was observed in all types of BCCs to a greater or lesser degree. Ultrastructural thickening, multiplication, or discontinuity of basement membranes were found in all 19 cases examined with a greater or lesser degree, although they were most frequently observed around the cell nests showing micronodular growth patterns. It was concluded that deep dermal and marginal invasions were the most ominous signs of recurrence of BCCs. Although the disruption of basement membranes might participate in the local aggressiveness of BCCs, especially in the tumor cells showing micronodular infiltrative growth, other factors may concern the recurrence of BCCs.

Morphological development of the rat fetal pancreas

Rat fetal pancreata of days 12 to 19 of gestation and those of neonates were examined with light and electron microscopes. The pancreas arose from the primitive epithelium of the foregut as two primordia (dorsal and ventral pancreatic primordia) of epithelial cell nests surrounded with abundant fetal mesenchymal tissue between days 11 and 12. Primitive pancreatic islets, which mainly consisted of the endocrine cells with A cell type secretory granules, also appeared in the primordia at this age. The epithelial cell nests elongated gradually and had a branching cord-like arrangement. Two pancreatic primordia fused together on day 15, and an apparent ductular structure was observed on days 15 to 17. An acinar configuration of exocrine cells with zymogen granules gradually formed between days 17, 18 and 19. After birth, the volume of pancreatic parenchyma markedly increased and that of mesenchymal tissue prominently decreased. Ultrastructurally, the pancreatic primordia in the early stage showed immature epithelial features with the surrounding basement membrane and inconspicuous intercellular junctions. This might imply a plasticity in cellular differentiation of protodifferentiated pancreatic epithelial cells toward a ductular structure of immature exocrine pancreas which appeared later. In addition to the basement membrane, abundant fetal mesenchymal tissue was considered to play a possible role in the early morphogenesis in pancreatic development.

Hyalinized hemangioma of the liver

We report the case of a 65-yr-old woman with hyalinized hemangioma of the liver which, on radiological examination, resembled primary or metastatic carcinoma of the liver. She had undergone a partial colectomy for a sigmoid adenocarcinoma, followed by the diagnosis of a hepatic tumor with ultrasonic echogram 5 months later. The tumor was depicted as a low-density mass on plain computed tomography (CT), and an enhancement at the peripheral portion was noted by contrast CT. Hepatic angiography disclosed a faint pooling of contrast medium in segment 8. A subsementectomy of the liver was performed under the diagnosis of metastatic adenocarcinoma or hepatocellular carcinoma. Histologically, the tumor was composed of dense collagenous tissues with marked hyalinization and scattered sclerotic vessels. Elastic fibers were distributed concentrically around the vessels. Totally hyalinized sclerosis of hemangioma is uncommon, and can be erroneously diagnosed as carcinoma by radiologic examination. This unusual hemangioma is reported, with pertinent literature.

An ultrastructural comparison of sinusoids in hepatocellular carcinoma, adenomatous hyperplasia, and fetal liver

Transmission and scanning electron microscopic examinations were performed to evaluate the fine-structural differences in sinusoids of hepatocellular carcinoma, adenomatous hyperplasia of the liver, and fetal livers. In cancerous sinusoids, thickened endothelial cells with loss of sieve plates were conspicuous features. In the sinusoids of adenomatous hyperplasia, scanning electron microscopy showed apparent sieve plates, and basement membrane formation (capillarization) was less conspicuous than in carcinoma. In fetal livers, occasional large gaps as well as small fenestrations in the endothelium were noted. Basement membrane materials were not seen. It was concluded that the sinusoids of hepatocellular carcinoma lost the fine-structural nature of normal sinusoids and showed much more prominent capillarizations than the sinusoids of adenomatous hyperplasia, and that the fine structures of cancerous sinusoids were also different from those of the sinusoids in fetal livers.

A scanning electron microscopic study of postnatal development of rat peribiliary plexus

Hepatic microcirculation in the developing stages is not fully clarified. This study aimed at clarifying the development of hepatic microcirculation, especially peribiliary vascular plexuses, in neonatal rats by corrosion cast procedures and scanning electron microscopy. Peribiliary vascular plexuses of large bile ducts at the hilus of 1-day-old rats showed a simple capillary network that directly poured into the portal vein. The hepatic artery promptly tapered down into many small branches and ended in sinusoids or capillary plexuses around portal vein branches near the hilus. Neither apparent hepatic artery branches nor peribiliary vascular plexuses were found in the peripheral areas of the liver. On the seventh day, very loose peribiliary vascular plexuses and small hepatic artery branches appeared up to the peripheral portal tracts, and the peribiliary vascular plexuses of large bile ducts were still capillary networks. After the seventh day, peribiliary vascular plexuses of large and medium-sized portal tracts often poured into side branches of the portal vein rather than directly into the portal vein as shown in the rats from the first day mentioned above. Peribiliary vascular plexuses of the large bile duct in 2-week-old rats showed a double layer, that is, an outer layer composed of arteries and veins and an inner layer of capillary vessels, that resembled peribiliary vascular plexuses of adult livers. After nearly 4 wk, hepatic microcirculations had almost fully developed into those of adult rats. It was concluded that the gradual postnatal development of the hepatic arterial system and the peribiliary vascular plexuses occurred in parallel with the maturation of the intrahepatic biliary trees.

Dieulafoy's ulcer associated with the tortuous caliber persistent arteries: report of three cases

Many papers have reported that Dieulafoy's ulcer is one of the notorious causes of gastric hemorrhage. Three cases of shallow subfundic ulcers with massive bleeding are reported. The resected specimens have demonstrated that elevated caliber-persistent artery (CPA), a branch of the left gastric artery with few anastomoses, in the base of the ulcer has tortuous penetration from the serosa to submucosa, showing patchy, eccentric intimal fibroelastosis. These findings of CPA are almost the same in both anterior and posterior walls, namely both the ruptured and contralateral sides. Thus, morphogenesis of the ulcer may have originated from anatomical deviation, which is related to regional hypertension aggravated by longterm peristalsis, as well as aging.

Lymphoepithelial cyst of the pancreas in a 65-year-old man

A case of an extremely rare cystic lesion of the pancreas is presented. The multilocular cyst was found adjacent to the upper border of the pancreatic body, and the cyst contained bean curd lees-like substances. Histologically, the cyst wall consisted of mature keratinizing squamous epithelium and surrounding lymphoid tissue stroma, and the cyst was filled with keratinized materials. A histopathologic diagnosis of typical lymphoepithelial cyst of the pancreas, proposed by Truong et al (Am J Surg Pathol 11:899-903, 1987), was made. Its histogenesis is still unknown; however, we hypothesize that it might arise from a benign epithelial inclusion of a peripancreatic lymph node, followed by squamous metaplasia of the epithelial inclusion. We recently found a retropyloric lymph node with a squamous epithelial inclusion, which might support this hypothesis regarding the histogenesis of the cyst.

Melanocytic schwannoma in the spinal canal

A case of melanocytic schwannoma, a rare form of schwannian neoplasm, in the thoracolumbar spinal canal of a 52-year-old man is presented. Histopathologically, the tumor was composed of irregularly interlacing spindle-shaped cells showing cystic degeneration, with occasional pigmented tumor cells. The tumor cells showed a low degree of nuclear pleomorphism without any mitotic figures. These histological features were considered to be consistent with a benign schwannian tumor showing pigmentation. Most of the pigments were considered to be melanin histochemically and immunohistochemically. According to the pathological features of the present tumor and those described previously in the literature, the neoplastic Schwann cells were assumed to have melanogenetic capacity, and the concept of the common neural crest origin of Schwann cells and melanocytes appeared to be demonstrated in the present tumor.

An immunohistochemical study of sarcomatoid liver carcinomas

Six cases of primary hepatic carcinomas with a significant amount of sarcomatoid elements were examined by using immunohistochemical stainings. Four of the six cases were associated with ordinary hepatocellular carcinoma (HCC), one with cholangiocellular carcinoma (CCC), and one with mixed HCC and CCC. Alpha-fetoprotein and alpha-1-antitrypsin were negative in sarcomatoid cells of all cases; vimentin stained positively in sarcomatoid tumor cells in two of the six cases; and cytokeratin (CK8) was detected in five cases. The CK8 was not detected in tumor cells of two cases of hepatic angiosarcoma, two of metastatic leiomyosarcomas, and one of metastatic fibrosarcoma, although vimentin stained positively in all these true sarcomas. It was concluded that sarcomatoid dedifferentiation of liver carcinomas might derive from both HCC and CCC. In addition CK8 might be an excellent marker to make a differential diagnosis of sarcomatoid cancers from true metastatic or primary sarcomas of the liver.

Acute encephalopathy with hepatic steatosis induced by pantothenic acid antagonist, calcium hopantenate, in dogs

In Japan, acute encephalopathy with hepatic steatosis resembling Reye's syndrome has been reported to occur after treatment with the pantothenic acid antagonist, calcium hopantenate. We studied the causal relationship and the pathogenesis in dogs. The agent was administered to seven dogs at increasing doses over a period of 8 weeks. Anorexia, vomiting, and diarrhea were common clinical findings. In four dogs, coma suddenly developed after the appearance of gastrointestinal signs. Three animals died during periods when they were not under direct observation. The effects of the agent appear to be related to dose. Laboratory findings representing significant changes at the time of coma included hypoglycemia, leukocytosis, hyperammonemia, hyperlactatemia, and elevated levels of serum transaminases. Microvesicular hepatic steatosis and mitochondrial abnormalities were consistent pathological findings. The hepatic mitochondria were enlarged and characterized by an increased number of cristae and the presence of crystalloid inclusions. In a second group of four dogs, pantothenic acid was given in addition to and in the same amount as calcium hopantenate at increasing doses over a period of 8 weeks. All four dogs survived the 8 weeks and only one developed mild anorexia. No significant biochemical changes were found and neither hepatic steatosis nor mitochondrial abnormalities were observed. The addition of pantothenic acid prevented the development of the disorder in the four animals. These results show that calcium hopantenate produces acute encephalopathy with hepatic steatosis in dogs, by inducing a deficiency of pantothenic acid. The hepatic mitochondrial changes of this reaction differ from those of Reye's syndrome.

Clinicopathological study of pulmonary giant cell carcinomas with reference to prognosis of patients

Giant cell carcinomas of the lung have been notorious in fulminant clinical courses. Thus, this report describes two exceptionally favorable cases among six cases of giant cell carcinoma of the lung. Their histopathological features are a sharply-demarcated tumor of Stage I, absence of vascular permeation of the cancer cells, prominent lymphoid and plasma cell infiltration in the tumor tissue, and lymph follicle formation in the surrounding tissues. Another case with a Stage II tumor showed the same histopathological findings as the above two cases with the exception of lymphatic permeation of the cancer cells. This patient expired about one year after undergoing an operation. As conventional controls, the remaining three cases with Stage III tumors showed an alveolar extension of tumor cells and vascular permeation. There was a fulminant course after the operation. Notwithstanding similar intervals from their clinical onset to operation in the 4 cases other than Cases 4 and 6, their stages showed considerable variations. Hence, each histopathological feature might have substantiated the different clinical courses following the operation. Electron microscopy of three of the cases indicated double-membrane-bound blisters with intermediate junctions in the bizarre giant cells, and cancer cell differentiation toward both glandular and squamous directions.

Morphological changes of hepatic microcirculation in experimental rat cirrhosis: a scanning electron microscopic study

Morphological changes of hepatic microcirculation, especially peribiliary plexus, in experimental rat cirrhosis that resulted from the repeated intraperitoneal injections of N-diethylnitrosamine, 100 mg/kg body weight/one shot/week, were examined by scanning electron microscope. Control rats were treated with saline. Whole blood vessels of the rats were perfused by saline and stuffed with methylmethacrylated resin. Multiple nodular changes were seen in the livers after the five injections (5 wk) of N-diethylnitrosamine, and diffuse nodular transformations mimicking human cirrhosis after six injections (6 wk) were also seen. Overall changes in experimental rats were numerous vascular channels mainly composed of venous branches around the parenchymal nodules, increased arterioportal anastomoses and flattening of veins, especially hepatic vein branches. Peribiliary plexuses of the experimental rats were much richer in the vessels than those of the controls, and many dilated veins, ramified from portal vein branches, were present in the former. Direct connections between peribiliary plexuses and sinusoids or between peribiliary plexuses and portal veins increased in the experimental rats. Studies concerning microcirculatory changes of peribiliary plexuses in experimental rat cirrhosis are rare. It was concluded that the abnormal peribiliary plexuses in this experimental series might participate in a collateral circulation under a state of portal hypertension.

Primary actinomycosis in the liver

We present a case of a 71-year-old female with actinomycosis in the liver, which is a rare region to be primarily affected with actinomycosis. The diagnosis was done histopathologically with a partially resected liver specimen taken during surgery for choledocholithiasis. There were no clinical signs of Actinomyces infection before surgery. The hepatic lesion was a 2 cm sized nodule with histological appearances of abscess-forming suppurative inflammation with fibrosis, in which eosinophilic radiate granules with peripheral clubs were found. The Brown-Brenn stain showed Gram-positive branched filamentous bacilli, which were revealed as acid-fastness by the Ziehl-Neelsen method of Putt's modification. These findings were considered to be consistent with actinomycosis of the liver.

Fibrolamellar carcinoma of the liver in a middle-aged Korean man

A 42-year-old Korean man with a fibrolamellar carcinoma of the liver is described. His initial symptom was an epigastric mass without pain, which resulted in a left lobectomy of the liver. A whitish and hard tumor, 10 cm in maximum diameter, without any cirrhotic features was noted in the resected liver. Histologically, the tumor was composed of lamellarly distributed fibrous stroma and polyhedral large cancer cells, which showed eosinophilic granular cytoplasm and rounded nuclei. Prominent nucleoli, scattered pale bodies and numerous copper-binding protein deposits were seen in the cancer cells. Orcein-stain failed to show HBsAg-laden cells in both the cancerous and non-cancerous tissues, and alpha-fetoprotein was not seen in the cancer cells by an immuno-peroxidase staining. Fibrolamellar carcinoma has been found almost exclusively in Caucasians and is very rare in Orientals. We describe this rare case with a review of the literature.

Three-dimensional observation of the rat endocrine pancreas by a scanning electron microscope

A three-dimensional observation was performed on chemically digested rat pancreata and vascular corrosion casts of it with a scanning electron microscope. The Langerhans islets were sporadically situated in the exocrine tissue and were surrounded by the fibrous capsule, which was so tough that it could not be chemically digested easily. This capsule was considered to play different roles in the collection of the endocrine cells in a functional unit, in the prevention of secreted hormones spreading into the adjacent exocrine and stromal tissue, in the support of the microvascular structure, and in the protection for the islet cells from the pancreatic enzymes, which are leaking into the stromal spaces physiologically. The microvascular structure of the islet, disclosed by the corrosion vascular casts, showed afferent vessels branching into the capillaries at the periphery of the islet and entering the core of it by a twisted course. These findings were considered to be related to the islet cell distribution, that is, A and D cells are at the periphery of the islet and B cells at the center of it. This might support the existence of a hormonal regulating mechanism among endocrine cells. In addition, the efferent vessels from the islet that communicate to the vascular network of the exocrine tissue might suggest that the endocrine system also regulates the exocrine function in a circulatory dynamic state.

Globular cytoplasmic inclusion bodies in a metastatic hepatocellular carcinoma of the iliac bone

Globular filamentous bodies are one of the well-known inclusion bodies in hepatocellular carcinoma. The article describes a 56-year-old man with an occult hepatocellular carcinoma in whom the first histologic diagnosis was made from a biopsy from bone. Ultrastructural examination showed many globular filamentous bodies similar to Mallory bodies. The ultrastructural findings and the diagnostic value of these filamentous bodies are discussed.