Sixty-four cases of malignant lymphoma involving the liver were examined. Of these, 20 cases were histologically confirmed to be primary hepatic B-cell lymphoma. Twelve of these 20 cases were diffuse large B-cell lymphoma (DLBCL) and eight cases were mucosa-associated lymphoid tissue (MALT) lymphoma. Of the 12 cases of DLBCL, six were immunohistologically positive for CD10 and/or Bcl6 (indicating a germinal center phenotype), six were positive for Bcl2, and five were positive for CD25. Eight of the 12 DLBCL cases (66.7%) and two of the eight MALT lymphoma cases (25%) had serum anti-hepatitis C virus (HCV) antibodies and HCV RNA. The incidence of HCV infection was significantly higher in the hepatic DLBCL cases than in systemic intravascular large B-cell cases with liver involvement (one of 11 cases, 9.1%) and T/NK-cell lymphoma cases (one of 19 cases, 5.3%) (p < 0.01 for both). Two hepatic DLBCL cases (16.7%) had rheumatoid arthritis treated with methotrexate, and four MALT lymphoma cases (50%) had Sjögren’s syndrome, primary biliary cirrhosis, or autoimmune hepatitis; one case in each of these two groups was complicated by chronic HCV-seropositive hepatitis. Although primary hepatic lymphoma is rare, persistent inflammatory processes associated with HCV infection or autoimmune disease may play independent roles in the lymphomagenesis of hepatic B cells.

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).

Objectives: This study aimed to evaluate the relationship between the amount of aspirated debris during distal balloon-protected carotid artery stenting (CAS) and the pre-intervention plaque composition, as assessed by Virtual Histology™ (VH) intravascular ultrasound (IVUS). Methods: The study subjects were 25 consecutive patients (mean age, 73.0 ± 5.2 years; 20 males and 5 females) who underwent CAS under distal balloon protection. The average rate of carotid stenosis was 74.6 ± 12.9% by North American Symptomatic Carotid Endarterectomy Trial criteria. We assessed culprit plaque components by VH-IVUS before CAS. Aspirated debris was filtered, stained with HE and mounted onto glass slides. The quantity of debris was evaluated by measuring its surface area. We evaluated the relationship between the quantity of aspirated debris and VH-IVUS measurements before CAS. Results: The amount of debris during CAS was positively correlated with the total plaque volume in grayscale IVUS (Rs = 0.480, p = 0.015) and fibro-fatty volumes over the entire lesion length in VH-IVUS (Rs = 0.561, p = 0.001). Conclusions: Culprit lesions with large plaque volumes, especially larger fibro-fatty volumes, as imaged by VH-IVUS, are associated with large amounts of debris during balloon-protected CAS.

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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.