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One hundred and forty autopsy cases of systemic amyloidosis were examined using the potassium permanganate method for distinction of amyloid A protein from other amyloid proteins and an immunohistochemical technique. Of those cases, amyloid proteins were identified in 121 cases. There were 68 cases of amyloid A-related (AA) amyloidosis and these were the most common type among the cases (56.2%). There were 39 cases of immunoglobulin light chain-related (AL) amyloidosis (32.2%), six cases of beta 2-microglobulin-related (A beta 2M) amyloidosis (5%), and five cases of transthyretin-related (ATTR) amyloidosis (4.1%). Minute areas of amyloid deposits in four cases with AA were resistant to potassium permanganate pretreatment. In A beta 2M amyloidosis amyloid deposits were either resistant or sensitive to potassium permanganate pretreatment, from case to case. The coexistence of two different amyloid proteins was seen in three cases: one case had ATTR and A kappa types, and two cases had A beta 2M and AA types. Some discrepancies were seen between the immunohistochemical typing and clinical classification of amyloidosis referred to in the Annual of the Pathological Autopsy Cases in Japan, for example, one case of AA type in myeloma-associated amyloidosis and one case of AL type in secondary amyloidosis. From the present results, the importance of the immunohistochemical method in classifying amyloidosis is stressed.

Cytoplasmic inclusions and virus-like particles are described in blast cells of peripheral blood from a 16-year-old female with acute lymphoblastic leukemia. Three kinds of inclusions were identified on electron microscopy. The first type of inclusion was single membrane-bounded vacuoles, some of which contained virus-like particles, the second was lysosome-like structures, and the third appeared to be of mitochondrial origin. Virus-like particles were round in shape and had a diameter of 26 to 58 nm. They consisted of an electron-dense outer membrane and an electron-lucent core. At the present time the exact nature and significance of these virus-like particles still remain unclear.

To investigate the relationship between the tissue distribution and the types of amyloid proteins, the detailed histopathologic features of the available liver in 284 cases of amyloidosis were examined. We classified hepatic amyloidosis into three types, namely, the vascular pattern, parenchymal pattern, and stromal pattern according to the topographic distribution pattern of amyloid. Of the 152 amyloid A (AA) cases, all but one exhibited the vascular pattern; the single exception had the parenchymal pattern. Among 117 amyloid light chain (AL) cases, 51.3% exhibited the vascular pattern and 43.6% the parenchymal pattern. The stromal pattern was observed in 5.1% of the cases but was found only in AL amyloidosis. The parenchymal and stromal patterns in the liver seemed to be characteristic morphological distributions of AL amyloidosis. Routine histochemical study is useful to distinguish AL from AA, although some ethnic differences were apparent. Morphometric results showed that the walls of the hepatic arteries with amyloid deposition were significantly thicker than walls in arteries from the control group. The arterial walls in AA amyloidosis, especially, were significantly thicker than walls in AL amyloidosis of any pattern.

The incidence and anatomic distribution of isolated atrial amyloid (IAA) in 100 aging hearts were studied histologically and immunohistochemically using antibodies against alpha-human-atrial natriuretic peptide (alpha-ANP), human transthyretin (TTR) and human amyloid P component (AP). Ninety-one of 100 hearts (91%) had amyloid deposits in the atria. Amyloid deposits in all 91 hearts reacted with alpha-ANP and AP antisera, and in four hearts other amyloid deposits that reacted with TTR antiserum were coincidentally seen in the atria. The prevalence of IAA deposition, using a semiquantitative evaluation, was significantly higher in the hearts from patients over 80 years of age, from women, those weighing over 450 g, with a thickened left ventricular wall (> 1.4 cm) and with multiple myocardial scars. IAA deposition showed a significant distribution in the auricle and left atrium; it was located mostly in the interstitium of the subendocardial layer and the subendocardial myocardium. These results indicate that IAA occurs more frequently than previously appreciated in the elderly and in patients with certain cardiac disorders.

Tissues from three siblings with inclusion-cell (I-cell) disease (a 16 month old boy and two fetuses aborted at 20 and 18 weeks) were investigated histologically, histochemically and ultrastructurally. The lymphocytes, fibroblasts, endothelial cells, epithelial cells and histiocytes of various organs were affected. The cells had many intracytoplasmic vacuoles, which showed positive staining with colloidal iron, periodic acid-Schiff (PAS), alcian blue, and Sudan III and IV. Ultrastructurally, the cells contained various inclusion bodies, showing vesicles, granules, flocculent material, amorphous electron-dense globules and myelin structures. The amounts and ultrastructural features of the inclusion bodies differed among the various kinds of cells.

Although the pathogenesis has yet to be fully understood, β2-microglobulin (β2m) related amyloidosis is a frequent complication in long-term hemodialysis (HD) patients. In an att

An ultrastructural study of amyloid deposits in four cases of squamous cell carcinoma of uterine cervix was performed. The amyloid deposits reacted with anti-keratin antiserum on frozen sections. Amyloid deposits showed nodular (4 cases) and star-like forms (3 cases). Nodular amyloid deposits were composed of slightly whorled fibrils, measuring 7-10 nm in width. Some of them contained cellular debris and thicker, more electron-dense filaments than amyloid fibrils. In three cases, filamentous tumour cells and filamentous masses were observed together with amyloid. Star-like amyloid deposits were composed of bundles of straight amyloid fibrils. Some of the tumour cells in contact with star-like amyloid deposits had deep cytoplasmic invaginations, where closely packed amyloid fibrils were arrayed in parallel fashion. In addition, a few tumour cells had membrane-bound amyloid fibrils in the cytoplasm. It is suggested that nodular amyloid deposits are derived from the tumour cells through filamentous degeneration. Amyloid fibrils in star-like amyloid deposits are thought to be formed within the cytoplasm or in the vicinity of invaginated cytoplasmic membranes of the tumour cells.

Mice were injected subcutaneously with a single dose of sphingolipids. The sphingolipids tested were: ceramide with alpha-hydroxy fatty acids, ceramide with non-hydroxy fatty acids, glucocerebroside, sphingomyelin, and galactocerebroside. Lipids without sphingolipids served as a control. The mice were sacrificed 1, 2, 3, 4, 5 and 7 days after injection. Three mice were used for each experiment. The subcutaneous tissue at the injected area, the liver and the spleen were studied histologically. At 1-3 days after injection, numerous cytoplasmic inclusion bodies were observed in the macrophages and fibroblasts in the subcutaneous tissue, but not in the liver or the spleen. Ultrastructural studies of the inclusion bodies indicated that the sphingolipids taken up by the phagocytes retained their respective original shape during the 1-3 day stage. At days 4 and 5, the number of the inclusion bodies decreased, but they contained Farber bodies, i.e. curvilinear bodies 12 to 25 nm wide and up to 120 nm long. The mice with galactocerebroside were an exception, with parallel leaflets structures, but without the Farber bodies.

SUMMARY Cerebrovascular amyloid deposition (CVAD), caused by deposition of the P/A4 protein, has been previously identified as a cause of cerebral haemorrhage, yet its prevalence is uncertain. The presence of vascular amyloid was studied in brains of 169 patients by immunohistochemical and Congo red staining. Fifty patients had cerebra1 haemorrhage (CH), 56 had cerebral infarction (CI), and 63 had neither haemorrhage nor infarction (control group). CVAD was found in 38 per cent of the CH group, 25 per cent of the CI group, and 32 per cent of the control group. The incidence of CVAD increased with age in each group. Immunohistochemical staining with an antibody toB/A4 protein was more sensitive than Congo red staining in demonstrating the extent of vascular amyloid. Within the CH group, CVAD was present in the vessels at the site of haemorrhage in 6/8 (75 per cent) of pure superficial (lobar) cerebral haemorrhages. While amyloid was detected in vessels in the brain of 10/37 (27 per cent) of pure deep cerebral haemorrhages, none was present in vessels at the site of haemorrhage. CVAD is a common pathological finding in the elderly and has a significant association with pure superficial (lobar) cerebral haemorrhages. KEY WORDS-cerebrovascular amyloid, cerebral haemorrhage, cerebral infarction, P/A4 protein

The authors present the histologic features, immunohistochemical findings, and ultrastructure of a carcinosarcoma of the gallbladder containing rhabdomyosarcoma as a mesenchymal element. A pedunculated polypoid tumor protruded into the lumen from the fundus of the gallbladder. The neoplasm contained two divergent components. One was malignant mesenchymal tissue with rhabdomyoblastic differentiation; the other was ordinary adenocarcinoma which was observed predominantly at the base of the polyp. Immunohistochemically, the cytoplasm of the rhabdomyoblasts stained with anti-myoglobin, myosin, and muscle actin antibodies. Ultrastructurally, there were a large number of malignant mesenchymal tissues in which various stages of differentiated rhabdomyoblasts were noted. Ultrastructural study was particularly valuable for the identification of sarcomatous elements.

We report histochemical and immunohistochemical studies of two cases of testicular malacoplakia from 54-year-old (case 1) and 45-year-old (case 2) men and an ultrastructural study of case 1 with review of the literature. The testes were enlarged and the cut surface showed a neoplasma-like appearance. The testicular architecture was destroyed due to replacing by granulomatous lesion consisting predominantly of macrophages with abundant eosinophilic granular cytoplasm (so-called von Hansemann cell) in both cases. In the cytoplasm of von Hansemann cells, PAS-positive inclusion bodies were frequently observed. There was no histochemical evidence of iron or calcium deposition in the inclusion bodies. Immunohistochemically, positive materials for anti-α1-antitrypsin, anti-α1-antichymotrypsin and anti-Escherichia coli (E. coli) antibodies were seen in the cytoplasm of von Hansemann cells in granulomatous lesion. Thus, we considered the inclusion body as Michaelis-Gutmann (M-G) body. Electron microscopically, various kinds of phagosomes, including M-G structures which do not seem to contain calcium, were observed in the cytoplasm of von Hansemann cells in case 1. Although, the pathogenesis of testicular malacoplakia is still unclear, bacterial infection, especially E. coli infection, may be play an important role for the pathogenesis of testicular malacoplakia.

A 61 year old male was diagnosed as having hypertensive nephropathy at age 50. Chronic renal failure at age 55 resulted in his beginning hemodialysis at age 57. A diagnosis of myeloma was also established at age 57 on the basis of Bence Jones proteinuria, increased bone marrow plasma cells and anemia. Amyloid deposits developed in nodules on the eyelids, in the carpal joints, cervical spine, shoulder synovial membrane, bone marrow and rectum. By immunostaining, the amyloid deposits reacted with anti-Ak and less abundantly with anti-4β2M.

To investigate the relationship between cerebral amyloid angiopathy and subcortical (lobar) hemorrhage, we examined the severity of amyloid deposition in the leptomeningeal, cortical and subcortical arteries in 28 autopsied elderly patients with cerebral amyloid angiopathy with subcortical hemorrhage, deep cerebral hemorrhage or without hemorrhage. The severity was evaluated in terms of the frequency of amyloid-laden arteries and the degree of amyloid deposition within the arteries. The frequency of amyloid-laden arteries, especially among arteries over 200 microns in diameter, was higher in subcortical hemorrhage group than in the deep hemorrhage group and the non-hemorrhage group, and when the degree of amyloid deposition in the arteries was divided into four grades (none, mild, moderate or severe), the severity was higher in the subcortical hemorrhage group than in the deep cerebral hemorrhage group and the non-hemorrhage group. These results suggest that severe cerebral amyloid angiopathy is related to non-traumatic subcortical hemorrhage in elderly persons.

We compared intraneuronal polyglucosan body (PGB) in brains from two patients diagnosed as having Lafora disease and from 18 aged dogs (age range: 10 to 22 years, various breeds). PGBs appeared as various-sized spheroids intensely stained with periodic acid Schiff (PAS) in both humans and aged dogs. lmmunohistochemistry with a monoclonal antibody raised against human polyglucosan showed positive staining of the PGBs. Ultrastructurally, PGBs in both humans and aged dogs were composed of fibril-like structures 4 to 20 nm wide. Electron-dense material formed the central cores of the fibrils, but was also scattered in their peripheral areas. The fibril-like structures were intensely stained upon application of the Thiery procedure. lmmunoelectron microscopy showed that the fibril-like structures were specifically labeled with gold particles. The histological, immunohistochemical and ultrastructural features of the PGBs in humans and aged dogs were quite similar. Acta Pathol Jpn 42: 787–792, 1992.

Two cases of intrascrotal sclerosing lipogranuloma are reported in which affected adipose tissues showed peculiar membranocystic lesions (MCL) similar to the features described in Nasu-Hakola disease. On light microscopy, the MCL were seen in the degenerative fatty tissues and within multinucleated giant cells, which were positive for periodic acid-Schiff stain and resistant to diastase digestion. Ultrastructurally, two types of MCL were observed; one type was characterized by thick membranes composed of vesicular to minute tubular or fibrillar substructures, and the other type was characterized by thin membranes composed of only small numbers of tiny vesicles. The substructures in both types of MCL contained lipid droplets similar to those in the inner space. These results support the concept that the membranes in the MCL are derived from degenerated fat droplets.

We report a case of primary localized amyloidosis of the bladder causing renal failure. Immuno-histochemically, amyloid fibril protein originated from the λ type light chain of immunoglobulin.

A boy with Farber's lipogranulomatosis is reported. Excessive ceramide was revealed by thin-layer chromatography of the extracts from the liver. Acid ceramidase activity of the liver was 31.5% of control with exogenous substrate and 33.3% without exogenous substrate. The histological appearance showed granulomatous lesions, composed of spindle or oval-shaped storage cells and proliferation of the connective tissues, in the subcutaneous tissue of the lower lip, periarticular regions and the pericardium. Histo-chemically the storage cells were revealed to contain lipid and polysaccharide. The foreign body granuloma formed by the surgical suture in the liver was surrounded by a large number of foamy cells. In gastrointestinal mucosa widespread erosion, disappearance of glands and abundant collagen fibers were noted. On electron microscopy, the spindle or oval shaped cells in the subcutis of the lip had intracytoplasmic inclusions containing granular or fibrillar materials and a smaller number of curvilinear structures, so called “Farber bodies”. Our case was a typical clinical and histopathological presentation of Farber's lipogranulomatosis. However, ceramidase activity was higher than in previous descriptions, and severe gastrointestinal lesions and the appearance of a large number of foamy cells around the foreign body granuloma have not been described previously.

Neutrophils and spleens were prepared from mice after treatment to induce amyloid deposition. The deposition of amyloid was accelerated in normal recipients by intravenous injection of more than 2 x 10(4) neutrophils, and intraperitoneal injection of supernatants obtained by homogenization and centrifugation of the neutrophils and spleens. The supernatants were subjected individually to DEAE ion-exchange chromatography. Amyloid enhancing factor (AEF) activity was present in peaks eluted at an NaCl concentration of 0.17 M. The fractions containing AEF were subjected to high-performance liquid chromatography (HPLC), and AEF was eluted at a position corresponding to about 15 KDa. Purified AEF was analyzed by amino acid sequencing and gas chromatography. The N-terminal amino acid was blocked, and AEF contained some saccharides including glucose, mannose, galactosamine and sialic acid, and an undefined substance (probably derived from certain proteins). Immunoelectron microscopy by the pre-embedding method using an anti-AEF antiserum demonstrated that the cytosol, but not primary and specific granules in neutrophils from the spleen of amyloid-laden mice, reacted with the antiserum. These findings suggest that AEF is a glycoprotein associated with neutrophils.

Immunohistochemical and immunoelectron microscopical studies were carried out on 28 aged dogs' brains. Amyloid deposits were seen in the arteries and capillaries in the leptomeninges and in superficial areas of the cortices in 19 (67.9%) of the 28 dogs (10–22 years of age). Immunohistochemically, these amyloid deposits were reactive for anti-β/A4 antibody. Additionally, a variable number of parenchymal deposits with diffuse β/A4-immunoreactivity (diffuse plaques) was also noted throughout the cerebral cortex in 24/28 dogs (85.7%). However, these plaque lesions were undetectable in Congo red staining. Electron microscopically, amyloid fibrils, measuring 10 nm in width, were located mainly in the tunica media of the arteries, and in less involved vessels they tended to be present among collagen fibres in the adventitia and smooth muscle cells in the outer layer of the media. The plaque lesions appeared to contain sparse aggregations of amyloid fibrils. In immunoelectron microscopica; examinations, all amyloid fibrils in both blood vessels and plaques were selectively labelled by gold particles. These findings indicate that aged dogs can provide a useful experimental model for research into the β/A4-type of cerebral amyloidosis commonly seen in Alzheimer's disease.

After homogenation and centrifugation of the neutrophils and the spleens obtained from mice with an injection of amyloidogen, the supernatants were individually applied to DEAE ion exchange chromatogrophy. AEF activity in each fraction was tested. AEF activity was present in peaks eluted at concentration of 0.17M NaCl. The fractions containing AEF were subjected to gel chromatographic HPLC, and AEF was eluted at about 15KD. Purified-AEF was analyzed by gas chromatography. AEF contained in some saccharides consisting of glucose, mannose, galactosamine and sialic acid, and undefined substance (probably derived from proteins). From the present results, it is suggested that AEF is a glycoprotein in the neutrophilic granules.

Evidence for amyloid fibril formation in rough endoplasmic reticulum (rER) of plasma cells from a patient with localized Aλ amyloidosis is described. The inclusions in rER of plasma cells were composed of tightly packed, regular arrays of fibrils cut in both longitudinal and cross section. The fibrils, measuring 10 nm in width, were always oriented parallel to the long axis of the inclusions. By immunoelectron microscopy with anti-human Aλ antiserum, gold particles labeled the amyloid fibrils located both in the rER of plasma cells and in the extracellular space. In addition electron-dense material in the dilated rER was occasionally labeled. These findings suggest that at least some amyloid fibrils are unequivocally created in the rER of plasma cells.

Amyloid formation and resorption in the murine liver were examined by the technique of protein A-gold immunoelectron microscopy using anti-mouse AA antiserum. The liver biopsy was done 4 days after the injections of amyloid enhancing factor (AEF) and casein solution, and the mice were sacrificed 1 and 2 weeks after the biopsy. In the biopsied liver, gold particles labeled several inclusions within the cytoplasm of the Kupffer cells. These inclusions, being round to fusiform in shape, were constantly membrane-bounded. Some of them contained fibrillar structures, corresponding to amyloid fibrils, while most were composed of a homogeneous, granular matrix. In the stage of amyloid resorption, gold particles labeled irregularly-shaped phagosomes in the Kupffer cells. These phagosomes also contained flocculent and phagocytized membranous structures. The present results provide an additional support for the concept that some amyloid fibrils are formed within lysosome-derived organelles of the Kupffer cells.

Kupffer cells (KC) were isolated from amyloid-laden livers of mice (AKC) and non-amyloid livers (NKC). After attachment of AKC to petri dishes, the supernatants containing floating amyloid were centrif-uged and the pellet was added to NKC (NKCamy). The deposition of amyloid was observed in many of the AKC and some of NKCamy. After 14 d culture when the deposits of amyloid had almost disappeared, amyloid enhancing factor (AEF) and serum amyloid A (SAA) rich serum were added. The number of amyloid deposits fairly increased in AKC and NKCamy compared with the control cultures. Although no deposit of amyloid was found in the treated NKC, their morphological changes were remarkable. After treatment with AEF, they were swollen and the cell borders became clear. Under the scanning electron microscpy (SEM), stimulated cells displayed prominent petal-like ruffles, ridges and frequent filopodia. After treatent with AEF and SAA-rich liver extract, a fine granular substance was phagocytized, but amyloid fibrils could not be found in the NKC.

Amyloid deposits were seen in the arteries and capillaries in the leptomeninges and superficial brain cortices in 19 (67.9%) of 28 aged dogs. Immunohistochemically, cerebrovascular amyloid was reactive to anti-s protein (s/A4) antibody. Additionally, a variable number of diffuse plaques reacted with anti-s/A4 antibody were also noted throughout the cerebral cortex in 24/28 dogs (85.7%). These diffuse plaques were not detected by Congo red or silver impregnation. Electron microscopically, amyloid fibrils, measuring 10 nm in width were located in the tunica media of the arteries. A few aggregations of amyloid fibrils were noted in the diffuse plaques. Immunoelectron microscopically, gold particles labeled the amyloid fibrils in the blood vessels and brain cortex. These findings demonstrated that aged dogs provide a useful animal model for many aspects of s/A4 amyloidosis.

We describe histological, immunohistochemical, and ultrastructural findings in a filiform large cell lymphoma of the spleen in a 73-year-old man. The spleen weighed 300 g and contained a nodular mass of dimensions 4 x 2.8 x 3 cm that was lobular, raised, and well circumscribed. Light microscopically, the lesion was composed of compact cellular aggregates having large nuclei with evenly dispersed chromatin and a single large nucleolus or occasionally two to three small nucleoli. Immunohistochemically, the tumor cells were reactive to antibodies to leukocyte common antigen and MBI. Electron microscopically, most tumor cells were covered with tall, delicate, filiform cytoplasmic projections resembling microvilli in number and distribution. Filiform cytoplasmic projections varied from 50 to 200 nm in width and were at right or oblique angles to the surface. They appeared to be parallel but were frequently undulated, curved, or branching, forming in places small tufts. The pattern was more clearly noted on thick sections examined at an accelerating voltage of 200 kV.

An unusual cerebral tumor is reported in a 14-year-old boy. On light and electron microscopy, the constituent cells were very complex; the majority of the neoplastic cells were primitive neuroectodermal cells dispersed in myxomatous or fibrous stroma. Neoplastic neuronal cells and hypertrophic astrocytes were also observed in these areas. The neuronal cells showed a continuous spectrum of differentiation from very primitive to mature ganglion cells. Furthermore, the tumor contained a highly cellular discrete area consisting of neuroblasts and their precursor cells. From these findings, a diagnosis of composite ganglioneuroblastoma was made.

Monoclonal antibody (McAb) was raised against synthesized short peptides corresponding to 37–47 residues from N-terminus of amino acid sequence of human AA protein. The McAb reacted immunohistochemically to amyloid tissues from cow, mouse, swan, and human AA amyloidosis. We concluded that the McAb was useful for identification of AA type amyloidosis of various species, and that the 37–47 residues were effective antigenic sites in AA protein.

In order to clarify the mechanism for the formation of foamy cells (macrophages with foamy appearance) associated with increased erythrophagocytosis, we tried to reproduce these cells in mice by subcutaneous injection of intact red blood cells (RBCs), OsO, -treated RBCs (Os-RBCs), glutaraldehy de-treated RBCs (G-RBCs), or isolated red cell membranes, and time-course observation was done by light and electron microscopy. Foamy cells were induced by the latter two methods. Within the macrophages, G-RBCs were fragmented into spherules by newly formed small vacuoles, and with time these spherules lost their hemoglobin content transforming into small vacuoles with translucent matrix. In most of these vacuoles, red cell membrane structure was discernible adjacent to the phagocytic vacuole. Such macrophages containing abundant small vacuoles appear foamy in light microscopy. Foamy cells induced by injection of red blood cell membranes were positive for lipid stains and contained abundant laminated membrane structures in electron microscopy. These results suggest that the foamy cells related with increased erythrophagocytosis are heterogeneous with respect to their pathogenesis and cellular inclusions, and proteinaceous constituents resistant to intracellular digestion are also responsible for the occurrence of foamy cells.

Amyloid deposits in three functioning human pituitary adenomas (two prolactin (PRL) -secreting and one growth hormone (GH)-secreting) were studied by immunohistochemical techniques. Histological diagnosis was mixed pituitary adenoma in all cases. The amyloid deposits of all cases were negative for GH, AA protein, Aκ, Aλ, and γ-trace, but the amyloid deposits of two cases were strongly positive for PRL. Most cells surrounding amyloid were negative for all antibodies but a few cells were positive for PRL. From these findings, it was strongly suggested that the amyloid in pituitary adenoma is a kind of AE protein and of hormonal origin. Serum hormonal level, radiation, and bromocriptine therapies might not contribute to amyloid deposits.

Normal parathyroid glands from 128 autopsies aged 12 to 82 were examined and intrafollicular amyloid was found in 53 cases (41.4%). There was a clear association with age of the patients. Intrafollicular amyloid is thought to be concentrated material originating from the stored parathormone or its derivatives.

A 35-year-old man developed gelatinous drop-like corneal dystrophy at age 20. Amyloid deposits were located mainly in the anterior two thirds of the cornea. Ultrastructurally, amyloid fibrils were demonstrated beneath the corneal epithelium and in the cytoplasmic inclusions of the stromal macrophages.

Two autopsy cases of paraquat poisoning in which the patients died of severe respiratory distress are reported. Clinically, liver dysfunction, renal failure and pulmonary distress were main features. Histopathologically, the lungs showed alveolar fibrosis, hemorrhage, edema and inflammatory cell infiltration. Toxic liver injury was also evident. Multiple fibrin thrombi in various organs suggested the association of intravascular coagulation syndrome, which has not been hitherto described.

The fine structures of the red pulp of the spleen and the liver of a patient with autoimmune hemolytic anemia, neutropenia and thrombocytopenia associated with systemic lupus erythematosus are described. The red blood cells were phagocytized in toto by the splenic macrophages. These also contained neutrophils and platelets in various stages of degradation. Sinus endothelial cells revealed occasional erythrophagocytosis. The Kupffer cells in the liver occasionally contained red cells and platelets. These morphological findings and marked improvement of hematological abnormalities following splenectomy suggested that the spleen was the major site of destruction of blood cells. Undulating tubules associated with the endoplasmic reticulum were present in the sinus endothelial cells of the spleen.

Early amyloid deposition in the spleen was studied by immunoelectron microscopy following the administration of rapid amyloid-inducing agents to mice. Two days after the injection of an amyloid-enhancing factor and casein solution, a small amount of amyloid material was observed at the border of the white pulp and the marginal zone (perifollicular area) and also within the white pulp. At this stage, amyloid fibrils were seen mainly in an extracellular distribution along the cytoplasmic processes of reticular cells and also in the cytoplasmic invaginations of macrophages. By immunoelectron microscopy, gold particles labelled fibrillar structures in lysosome-derived organelles in some macrophages as well as dense bodies consisted of a homogeneous, granular matrix not having any recognizable fibrillar structures. Similar immuno-labelled organelles were also observed in the amyloid resorption stage, although, at that stage, they commonly contained other phagocytized materials as well. From these findings, we suggest that at least some amyloid fibrils are polymerized in the cytoplasm of the macrophages by the proteolytic cleavage of previously pinocytized serum amyloid A protein (SAA).

Liver biopsy materials of two siblings with type IV glycogenosis were studied by light and electron microscopy. Biochemical analysis was added using autopsy material in one of the two cases. Two kinds of polysaccharides were noted not only in the cardiac muscle, skeletal muscles, smooth muscles and reticuloendothelial cells, but also in the neutrophils and platelets. One was glycogen and the other was similar to amylopectin. Ultrastructurally, a large amount of fibrils, 60 A in width, glycogen rosettes and glycogen granules were detected in those cells. Branching glycosyltransferase deficiency was biochemically confirmed in one case examined.

Fine structures of melanosomes incidentally found in the secretory cells of the paranasal sinusal glands associated with nasal malignant melanoma are described and their origin is discussed. It is suggested that these melanosomes in the secretory cells are not de novo products but are ingested by cytocrine process.

Amyloid depositions of pancreatic islets were investigated with electron microscopy in a case of type III glycogenosis. Beta cells adjoining small amyloid depositions were shown to have cytoplasmic invaginations where closely packed amyloid fibrils were disclosed regularly orientated amyloid bundles. In the cytoplasm of the beta cells, some membrane-bounded vesicles contained amyloid fibrils and a few beta granules directly transformed into the fibrils within the vesicles. These findings indicate that, at least in this case, the beta cells play a crucial role in the formation of insular amyloid.

By light and electron microscopy, we observed foamy cells in the spleens from a patient with hemolytic anemia due to red cell adenosine deaminase (ADA) overproduction, a patient with rheumatoid arthritis (RA) treated with gold, and patients with idiopathic thrombocytopenic purpura (ITP). The foamy cells associated with red cell ADA overproduction were essentially similar to Gaucher-like cells described in patients with thalassemia, and it was suggested that the accelerated destruction of red cells was one of the factors responsible for the development of foamy cells. Foamy cells in ITP and RA were closely associated with an increased destruction of platelets in the spleen. Morphologic transitions between phagocytosed platelets and myelin-like materials were traced in these disorders. In RA, however, foamy cells were heterogeneous from an ultrastructural standpoint, with different cytoplasmic inclusions. In addition to myelin-like materials, dense bodies, vacuoles with flocculent materials, and gold were noted in most of foamy cells. As gold compounds are known to inhibit lysosomal enzymes, we surmise that an acquired disturbance in lysosomal digestion is partially responsible for the accumulation of intermediate metabolites. In the pathogenesis of foamy cells associated with blood cell dyscrasia, the accelerated destruction of blood cells and/or acquired disorders in catabolic pathways within the macrophages are suggested to be the underlying mechanism of an intralysosomal accumulation of incompletely degraded cellular debris.

A large number of foamy cells were noted in the spleens from fourteen ITP patients, and two patients -who received a large amount of platelet rich plasma. Using the unlabelled immunoperoxidase method, these foamy cells were shown to contain platelet antigen. Platelets in varying stages of intracellular digestion, from intact-apperaring forms to myelin-like materials, were disclosed in foamy cells. Foamy cells were experimentally induced in granulomas by subcutaneous injection of platelets with or without accompanied administration of steroid, the platelets reacted with anti-murine platelet antibody, commercialized phospholipids (PE, PC, SM, PS, and the mixture of them), and the red blood cell membrane. The foamy cells induced by the subcutaneous injection of platelets are similar to those in the spleens of ITP patients. The lipid in foamy cells is chiefly derived from the membrane phospholipid of injected platelets. Concentric myelin-like materials were also noted in the foamy cells after injection of erythrocyte membrane. The myelin-like materials in these foamy cells are similar to those appearing in macrophages following injection of PC and SM. This suggests that these phospholipids derived from cell membrane are more resistant to intracellular digestion by lysosomal enzymes. We conclude that the foamy appearance of the cordal macrophage in ITP spleens results from incomplete intracellular degradation of platelet membrane.

Ultrastructural and immunocytochemical features of three human insulinomas, one with metastases and the other two with psammoma bodies and amyloid, respectively, are described. Neoplastic cells of all patients reacted with antihuman insulin antibody using the peroxidase-antiperoxidase (PAP) method. Ultrastructurally, neoplastic cells consisted of light cells and dark cells, both of which had a large number of secretory granules, microfilaments, ceroid bodies, and phagolysosomes. Psammoma bodies seemed to originate from neoplastic cell debris in one tumor. In another case, amyloid fibrils appeared to be produced by tumor cells, and there was a close association of amyloid with secretory granules.

The results of clinical, morphologic, and histologic analysis of nine XY complete moles (six karyotyped, three Y-chromatin positive) were compared with the results from analysis of 16 XX moles. Five of the nine XY moles were proved to result from dispermy while all the 16 XX moles studied originated from the doubling of a haploid sperm. At follow-up delayed decrease or rebound of urinary (or serum) human chorionic gonadotropin levels was noted in three of eight women with XY moles and in five of 15 women with XX moles. One woman with an XY mole was treated for lung metastasis, but her condition remained stable over a 4-year follow-up period. No appreciable difference was noted in the gross and microscopic findings between the XY and XX moles. On the other hand, differences were noted between younger (12 weeks or less of menstrual age) and older (13 weeks or more) moles. Younger moles had smaller, elliptic or club-shaped villi with numerous secondary villous sprouts, poorly demarcated central cisternae, and frequent mesenchymal capillaries. Older moles had larger, oval or globular villi with sparse villous sprouts, well-developed central cisternae, and less frequent remnants of capillaries. Trophoblastic hyperplasia was more marked in older than in younger moles.

A 7-year-old boy, who was diagnosed as typical SSPE by clinical data and laboratory findings, was autopsied and observed by immunofluorescent techniques, light and electron microscope. The morphological characteristics in the brain were perivascular cuffings with plasma cells, lymphocytes and mononuclear cells, gliosis and a large number of intranuclear and intracytoplasmic inclusions in the neuroglias and nerve cells. Various kinds of intranuclear inclusions were elucidated by electron microscopy and the fin structures of these inclusions were described in detail. At least five types of intranuclear inclusions were regarded as specific in SSPE. The presence of intranuclear inclusions of mononuclear cells in the lungs resembling the inclusions in the neuroglias suggested that the disease was not localized in the brain but could be disseminated throughout the body.

Light and electron microscopic studies of the spleen and liver from a patient with hereditary elliptocytosis have been reported. Characteristic findings are congestion of the cordal space, diminished variation of the erythrocyte shape in the cord, relatively empty sinuses and erythrophagocytosis by the cordal macrophages. The same basic defect of the red cell membrane as has been documented in hereditary sperocytosis might be a possible explanation on the pathogenesis of this rare hemolytic anemia.

Polyglucosan was extracted from the myocardium of a patient with Lafora disease. Gas chromatographic analysis of the isolated polyglucosan revealed glucose as the only sugar component. Monoclonal antibodies (MAb) were raised against the isolated polyglucosan. With the MAb, immunocytochemistry showed positive staining of Lafora bodies, corpora amylacea, basophilic degeneration of the cardiac muscle cells, and inclusion bodies within cardiac muscle cells and the hepatocytes of patients with Lafora disease and type IV glycogenosis (Andersen's disease). These findings indicate that cells of the latter group share antigenicity with Lafora bodies.