Shigemi Fuyama

Subcutaneous seeding of small hepatocellular carcinoma after fine needle aspiration biopsy

Ultrasonically guided fine needle (21 gauge) aspiration biopsy (FNAB) was performed on a patient with a hepatocellular carcinoma (HCC) measuring 1.5 × 1.5 cm in segment VI of the liver. The tumour was located just beneath the liver surface. Subsegmentectomy of segment VI was performed. Twelve months after the biopsy and 10 months after the operation, levels of alpha‐fetoprotein (AFP) and protein induced by Vitamin K absence or antagonist‐II (PIVKA‐II) increased gradually without any evidence of recurrence of HCC in the liver. Thirteen months after the biopsy, the patient palpated a hard subcutaneous nodule 1.5 cm in diameter in the right lower anterior chest wall at the insertion site of the biopsy needle. A subcutaneous tumour was excised and histological examination revealed moderately differentiated HCC. The levels of AFP and PIVKA‐II normalized thereafter. These tumour markers were therefore useful for diagnosing the subcutaneous nodule as a metastatic HCC. The patient is currently doing well without further recurrence of HCC or needle‐tract seeding 23 months after subsegmentectomy and 11 months after excision of the subcutaneous tumour.

Inhibition of mouse natural killer cytotoxicity by heparin

The effect of heparin on mouse natural killer (NK) cytotoxicity was investigated. Heparin greatly inhibited NK activity at a concentration of more than 10 units/ml. Inhibition of NK cytotoxicity was observed only when heparin was present in the reaction mixture of the cytotoxicity assay. The results of kinetic study of NK inhibition and target-effector binding assay proposed the possibility that heparin inhibits NK cytotoxicity after the binding of effector cells to target cells. Dextran sulfate, the heparin analog, which has potent negative charge also had an inhibitory effect on NK activity. Fractionation of heparin on Sephadex A-25 column revealed the parallelism of the negative charge and the inhibitory effect of heparin on NK cytotoxicity. These results demonstrated that polyanion could modulate NK cytotoxicity.

Small angiomyolipoma of the liver diagnosed by fine-needle aspiration biopsy under ultrasound guidance

The first reported case of small hepatic angiomyolipoma to be diagnosed by fine‐needle aspiration biopsy (FNAB) is described. A 53 year old man presented with a tumour in segment VI of the liver measuring 0.9 × 0.8 cm. The tumour was hyperechoic on ultrasound examination, showed relatively low density (+ 33 Hounsfield units) on computed tomography (CT), and was hypervascular on angiography. Computed tomography during arterial portography demonstrated a perfusion defect. Magnetic resonance imaging (MRI) revealed high intensity by both T1‐ and T2‐weighted imaging. Diagnosis could not be obtained by these imaging modalities, but it was established successfully by FNAB under ultrasound guidance. Histologically, the tumour was an angiomyolipoma made up of three components: blood vessels, smooth muscle and fatty tissue. Surgery is unnecessary for this benign condition, and the patient has been followed up. Ten months later, the patient is currently doing well without growth of the hepatic angiomyolipoma.

Effector phenotypes and mechanisms of antitumor immune reactivity of tumor-immunized and tumor-bearing mice in two syngeneic tumors

By using two different syngeneic tumors, Meth A sarcoma and RL male 1 lymphoma of BALB/c origin, the present study was designed to investigate the subset(s) of T cells mediating in vivo antitumor immune responses and some of the effector mechanisms of in vivo protective immunity in BALB/c mice immunized against tumor or bearing tumor. Spleen cells from the mice immunized against Meth A tumor or bearing Meth A tumor inhibited the growth of Meth A tumor in the Winn assay. In the Meth A-immunized mice, L3T4+ (CD4+) cells played a major role in mediating the inhibitory activity against Meth A tumor growth, whereas in the Meth A-bearing mice, the antitumor protective immunity was mediated by both L3T4+ and Lyt-2+ (CD8+) cells. Spleen cells from the Meth A-immunized or Meth A-bearing mice were not able to generate cytotoxic T lymphocytes (CTL) directed against Meth A tumor after the in vitro restimulation of spleen cells with mitomycin C (MMC)-treated Meth A cells, while fresh spleen cells from the Meth A-immunized or Meth A-bearing mice were able to induce the strong delayed-type hypersensitivity (DTH) responses to Meth A tumor. The DTH response to Meth A tumor was mediated by L3T4+ cells in the Meth A-immunized mice and by both L3T4+ and Lyt-2+ cells in the Meth A-bearing mice. In the similar experiments performed in the RL male 1 lymphoma, the antitumor activity in spleen cells from the RL male 1-immunized or RL male 1-bearing mice depended on Lyt-2+ but not L3T4+ cells in the Winn assay. When spleen cells from the RL male 1-immunized or RL male 1-bearing mice were cultured with MMC-treated RL male 1 cells for 5 days, an appreciable CTL response to RL male 1 tumor was induced. These results suggest that the nature of tumor and/or tumor antigens determines which T cell subset is required to exhibit the protective immunity against tumor and thus the different effector mechanisms could be induced in the different tumor models. Furthermore, these data support the conclusion that antitumor T cell responses are affected by the immune state of host to tumor.

CASE REPORT: Expression of Embryonic-Form Smooth Muscle Myosin Heavy Chain in a Gastrointestinal Stromal Tumor of the Greater Omentum

Recent studies have supported the hypothesis that gastrointestinal stromal tumors (GIST) originate in a stem cell that differentiates toward an interstitial cell of Cajal (ICC) phenotype (1–3). The ICCs, which have been shown to form a network at the outer edge of the submucosa, in the circular muscle layer, and around the myenteric plexus, have a pace-making function in the gastrointestinal tract (4). ICCs consistently express c-kit (CD117), a protooncogene receptor tyrosine kinase, and some of them appear to be positive for CD34 (3). Thus, CD117 and CD34 have now been used as important immunohistochemical markers for GISTs. Embryonic-form smooth muscle myosin heavy chain (EMHC), known as the nonmuscle MHC isoform, has been shown in the brain and proliferating smooth muscle cells, as in embryonic aorta and atherosclerotic intima (5–7). A recent report demonstrated that developmental ICCs and smooth muscle cells are derived from a common progenitor cell, which coexpresses CD117 and EMHC in the fetal stage (8). Moreover, Sakurai et al his revealed that most GISTs coexpress CD117 and EMHC (9). However, in the extragastrointestinal stromal tumors (EGIST), examinations of expression of EMHC have never been reported. We here describe a spindle cell sarcoma of the greater omentum, unusually presenting as an intrapelvic huge mass. In this study, we investigated the expression of CD117, CD34, and EMHC in the tumor by immunohistochemistry. Moreover, to investigate the molecular characteristics of EMHC in this tumor, reverse transcriptase–polymerase chain reaction (RTPCR) and immunoblot analysis were performed. We suggest that this tumor is compatible with the concept of EGIST. We also discuss the normal counterpart cell of the tumor.

In Vitro Immune Complex Binding Assay to Examine the Mechanism of Immune Complex Trapping by Human Follicular Dendritic Cells (FDC)

The trapping and long term retention of exogenous or autogenous antigens in the form of immune complex (IC) is one of major cardinal features of follicular dendritic cells (FDC). This tapping are thought to be mediated mainly by complement receptors (C’Rs), which are distributed abundantly on the surface of FDC1,2. The precise molecular mechanisms of this phenomenon, however, are still obscure. For example, controversial ideas have been reported as to the contribution of Fc-receptors (FcRs) to the trapping3,4,5. Especially the investigations are very limited in human system because it is difficult to establish the experimental approaches in vivo.

CASE REPORT: Deposition of Eosinophil Granule Proteins in Liver Associated with Allergic Bronchopulmonary Candidiasis

Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity disease of the lung caused by the inhalation of Aspergillus species (1). ABPA shows blood and pulmonary eosinophilia, increased serum immunoglobulin E (IgE) levels, episodic wheezing, and occasional expectoration of brown plugs. Eosinophil can damage tissues by the release of toxic granule proteins as major basic protein (MBP) and secreted eosinophil cationic protein (ECP). Recently, Candida species have also been implicated as a causative agent to produce clinical presentations similar to ABPA (2). The name proposed for this clinical entity is allergic bronchopulmonary candidiasis (ABPC) (2, 3). In a recent report, ABPA patients demonstrate elevated levels of interleukin-4 (IL-4) and IL-5 in brochoalveolar lavage (BAL) fluid (4). In murine models of ABPA, IL-4, IL-5, granulocytemacrophage colony-stimulating factor (GM-CSF), and intercellular adhesion molecule-1 (ICAM-1) have been indicated to induce blood and pulmonary eosinophilia and regulate IgE production, and so these molecules may play an important role in the pathogenesis of ABPA (5–7). In contrary, extrapulmonary lesions in ABPA have rarely been described (1). Several studies of ABPC have been presented, and to our knowledge, hepatomegaly and hepatic dysfunction have never been reported to be associated with ABPC (2, 3). In the present study, we report a patient with ABPC who developed hepatomegaly and eosinophilic hepatitis, and examined the expression of ICAM-1, IL-3, IL-4, IL-5, and GM-CSF apoptotic cells in liver tissue by immunohistochemistry; we also to investigate deposits of eosinophil granule proteins.

An Immunohistochemical Study on Isotypes of the Immune Complexes Trapped by Follicular Dendritic Cells (FDC) in Various Human Lymphoid Tissues

Follicular dendritic cells (FDC) are well known to trap and retain immune complexes (IC) containing various isotypes of immunoglobulins1,2,3. In addition, it has been reported that FDC retained IC with peculiar isotypes of immunoglobulins in certain diseases (IgAl in IgA nephropathy4,5, IgE in Kimura’s disease6 etc). These observations imply the particular relationships between isotype of the immunoglobulin constituting IC retained by FDC and immune responses or pathogenesis of certain immunopathological conditions. In the present study, distribution of each isotype of immunoglobulins was systemically examined in human various lymphoid tissues using immunohistochemical techniques with special reference to the reactivity within germinal centers (GC).