Pak-Kwan Hui

THE ACUTE LUPUS HEMOPHAGOCYTIC SYNDROME

OBJECTIVE To characterize an unusual mode of presentation of systemic lupus erythematosus: acute and severe pancytopenia related to reactive hemophagocytosis. DESIGN Retrospective case series. SETTING Two general community hospitals in Hong Kong. PATIENTS Six patients presenting with a reactive hemophagocytic syndrome, identified over a 3.5 year period, diagnosed with systemic lupus erythematosus according to the criteria of the American Rheumatism Association. RESULTS In addition to severe pancytopenia and marrow hemophagocytosis, other characteristic features were fever, hypocomplementemia, high antinuclear antibody titer, and cutaneous and visceral vasculitis. There was no evidence of an underlying infection. The pancytopenia responded dramatically to treatment with steroids. CONCLUSION Recognition of the acute lupus hemophagocytic syndrome and distinction from an infection-associated hemophagocytic syndrome is important because it responds well to steroid therapy. The evaluation of patients presenting with a hemophagocytic syndrome should include serologic tests for systemic lupus erythematosus.

Epithelioid haemangioma (angiolymphoid hyperplasia with eosinophilia) and Kimura's disease in Chinese.

Although Kimuras disease has often been considered to be identical to angiolymphoid hyperplasia with eosinophilia (epithelioid haemangioma), recent studies suggest that they are different clinicopathological entities. In this study, we have made a detailed morphological comparison of 10 cases of epithelioid haemangioma and 40 cases of Kimuras disease occurring in the Chinese population. The epithelioid haemangiomas occurred in the subcutaneous tissue, skin and maxillary antrum, whereas Kimuras disease affected the subcutaneous tissue, major salivary glands and lymph nodes. Distinctive features of epithelioid haemangiomas were exuberant proliferation of vessels lined by cuboidal to hobnail endothelial cells with irregular nuclei and cytoplasmic vacuoles, fibromyxoid matrix, involvement of muscular coat of blood vessels and zonation of inflammatory infiltrate towards the peripheral portion of the lesion. Distinctive features of Kimuras disease were florid lymphoid infiltrate with prominent lymphoid follicles, vascularization of germinal centres, germinal centre necrosis, marked eosinophilia with or without eosinophil abscess formation, proliferation of high endothelial venules, and sclerosis. The histological features suggest that epithelioid haemangioma is a proliferation of atypical endothelial cells, possibly neoplastic, that is associated with a variable inflammatory infiltrate, whereas Kimuras disease is primarily an inflammatory condition in which high endothelial venules are usually found.

Lymphadenopathy of Kimura's disease

Kimuras disease is an important category of reactive lymphadenopathy in the Oriental population. The enlarged nodes are mostly located in the head and neck region. Salient pathological changes include florid germinal centers, Warthin-Finkeldey type polykaryocytes, vascularization of germinal centers, increased postcapillary venules in the paracortex, eosinophilic infiltration, and sclerosis. The pathology of Kimuras disease is quite different from that of angiolymphoid hyperplasia with eosinophilia (epithelioid hemangioma). Immunoperoxidase studies show IgE reticular networks in germinal centers. Nondegranulated surface IgE-positive mast cells are present in the paracortex. The authors propose that Kimuras disease represents an aberrant immune reaction to an as yet unknown stimulus. Although the individual histological features are nonspecific, the constellation of features is highly characteristic of Kimuras disease. Since lymphadenopathy can herald involvement of other tissues and the prognosis is excellent, accurate diagnosis of this disease in lymph node biopsies may spare the patients unnecessary radical surgery.

Primary lymphoepithelioma‐like carcinoma of the lung. A clinicopathologic study of 11 cases

Background. Lymphoepithelioma‐like carcinoma (LELC), best known to occur in the nasopharynx, can arise in a variety of sites, such as the salivary gland, thymus, lung, stomach, and skin. Primary LELC of the lung is very rare, with only limited information in the literature.

Large B-cell lymphomas with a high content of reactive T cells

Twenty-one cases of large, B-cell lymphoma with an unusually high content of reactive T lymphocytes are described in this report. Fifteen patients presented with lymphoma in nodal sites and six patients presented with lymphoma in extranodal sites. With two exceptions, all patients were more than 50 years of age. The male to female ratio was 1:2. Histologically, isolated to small groups of large lymphoid cells were intermingled with many small lymphocytes. The large cells were neoplastic and exhibited B-lineage markers; immunoglobulin light chain restriction could be demonstrated in two thirds of the cases. There was a rich infiltrate of immunophenotypically mature T lymphocytes that comprised more than 50% of the cellular population. The T lymphocytes ranged from small cells with dark, round nuclei to slightly larger cells with elongated, irregular nuclei. There were occasional medium-sized blastic cells. There was also a variable infiltrate of histiocytes with or without epithelioid features, eosinophils and plasma cells, and increased vascularity. The peculiar morphologic features were also reproduced in other sites in the four patients for whom additional histologic materials were available for examination. We postulate that the abundance of T cells results either from a florid host reaction or from cytokine secretion by the neoplastic B cells, attracting T cells to the vicinity. The morphologic and immunologic features mimic those of a variety of benign lymphoproliferative diseases, angioimmunoblastic lymphadenopathy and lymphomas arising in angioimmunoblastic lymphadenopathy, peripheral T-cell lymphoma, secondary B-immunoblastic lymphoma, and Hodgkins disease. Careful morphologic evaluation and immunophenotypic studies using leukocyte antibodies reactive in paraffin-embedded sections are of great assistance in determining a diagnosis.

Proteome of Oriental ginseng Panax ginseng C. A. Meyer and the potential to use it as an identification tool

Oriental ginseng (Panax ginseng C. A. Meyer) and American ginseng (Panax quinquefolius) are two widely used valuable traditional Chinese medicines (TCM). Previously, the identification of ginseng was mainly performed by analyzing the ginsengnosides using high performance liquid chromatography and amplification of polymorphic DNA using polymerase chain reaction. However, these methods cannot be used to distinguish TCM samples which are from different parts (main root, lateral roots, rhizome head and skin) of ginseng and ginseng culture cells from wild‐grown ginseng. The present study aimed to identify different species of ginseng, different parts of the same ginseng and cultured cells of ginseng using a proteomic approach. Two‐dimensional electrophoresis (2‐DE) maps were established from the American ginseng main root, different parts (main root, lateral roots, rhizome head and skins) of Oriental ginseng and Oriental ginseng culture cells. Our results show that the 2‐DE maps of different ginseng samples contain sufficient differences to permit easy discrimination. We have also identified common and specific protein spots in the 2‐DE maps of different ginseng samples. The use of these “marker proteins” may help to speed up the identification process.

A simple guide to the terminology and application of leucocyte monoclonal antibodies

This review aims to provide a simple guide and quick reference to the terminology and diagnostic applications of leucocyte monoclonal antibodies. The differentiation cluster terminology, where applicable, is used throughout.

T- and T/natural killer-cell lymphomas of the salivary gland: A clinicopathologic, immunohistochemical and molecular study of six cases

Primary salivary gland lymphomas are almost always of B lineage, with most being represented by low grade B-cell lymphoma of mucosa-associated lymphoid tissue. This study characterizes the rare non-B-cell lymphomas of the salivary gland based on an analysis of six cases. All patients were men, with a mean age of 53.5 years. They presented with submandibular or parotid mass, which on histological examination showed extensive interstitial infiltration by small, medium-sized, or large lymphoid cells. There was prominent invasion and expansion of the ducts and acini in five cases. Angioinvasion was evident in two cases. Three cases were of T lineage and were CD56 negative; one of these cases expressed CD30. Three cases showed an immunophenotype of CD2+ CD3(f)- CD3(p)+ CD56+, consistent with T/natural killer (NK) cell lymphoma. In situ hybridization for Epstein-Barr virus (EBV)-encoded early nuclear RNA (EBER) showed positive reaction exclusively in the three CD56+ cases. Clonal T-cell populations were shown in two CD56-negative cases by polymerase chain reaction on paraffin sections using primers for the T-cell-receptor (TCR) gamma-chain gene, but not in the other four cases (the three CD56+ cases and one CD56- case). Four patients (two CD56+ and two CD56-) died within 3 years, and two were disease free at 4 and 1.5 years, respectively. This study shows that salivary gland T- or T/NK-cell lymphomas cannot be reliably distinguished from B-cell lymphomas on morphological grounds alone, because both can show prominent lymphoepithelial lesions. It appears that T/NK-cell lymphomas, which are often extranodal in localization and strongly associated with Epstein-Barr virus (EBV), show a predilection to involve the salivary glands as well.

Anaplastic large cell Ki‐1 lymphoma of bone

Anaplastic large cell Ki‐1 lymphoma is an uncommon type of non‐Hodgkins lymphoma that rarely presents primarily in the bone. Three such cases are reported. All patients were young and had bone pain; one had paraparesis as a complication of collapse of the thoracic vertebral body. The involvement was either monostotic or polyostotic. Radiologically, the lesions were lytic and had ill‐defined borders. Histologically, the large neoplastic cells had pleomorphic bizarre nuclei, prominent nucleoli, abundant deeply amphophilic cytoplasm, and paranuclear pale hof. They were admixed with variable numbers of inflammatory cells. One case each was of T‐cell, B‐cell, and non‐T non‐B lineage. All three cases showed excellent responses to chemotherapy with or without radiation therapy. Recognizing the lymphomatous nature of this highly pleomorphic tumor is important because of its potential curability with appropriate chemotherapy. Cancer 68:2186–2191, 1991.

Modes of Helicobacter colonization and gastric epithelial damage

A total of 144 gastric biopsies colonized by Helicobacter‐like organisms were studied under light and differential interference contrast microscopy for the modes of bacterial colonization. Biopsies were also graded for the degree of epithelial damage (epithelial‐damage‐grade: 0 to 6, in ascending order of severity) and density of Helicobacter‐like organism (Helicobacter‐grade: 0 to 6, in ascending order of bacterial density). Three modes of colonization were identified: free‐in‐mucus, surface‐adhesion and intercellular colonization. Because light miscroscopy cannot definitely prove the presence of intracellular colonization, bacteria located between cells and below the apical cell border were counted together as intercellular colonization. Bacteria free‐in‐mucus were seen in all biopsies. Surface adhesion was seen in 50–87.9% of biopsies, without obvious correlation with the epithelial‐damage‐ and Helicobacter‐grades. The incidences of intercellular and intracellular colonization were directly proportional to the epithelial‐damage‐ and Helicobacter‐grades. Free‐in‐mucus as the predominant mode of colonization was mainly seen in biopsies with lower (1–3) epithelial‐damage‐ and Helicobacter‐grades. Conversely, biopsies with intercellular colonization as the predominant mode of colonization were mainly cases with higher (4–6) epithelial‐damage‐ and Helicobacter‐grades. In cases showing predominantly bacteria between cells, 69.2% had a gastric ulcer whereas only 38.8% of cases showing predominantly bacteria free‐in‐mucus showed ulceration (P<0.01). These results indicate that Helicobacter‐like organisms can invade and penetrate between epithelial cells. When free‐in‐mucus, Helicobacter‐like organisms are less likely to induce epithelial damage. However, the more invasive modes of colonization (intercellular) were associated with severe epithelial damage and high Helicobacter density. The major factor associated with invasive modes of colonization was the quantity of bacteria. It is proposed that reduction or eradication of Helicobacter‐like organisms in the colonized stomach can decrease bacterial invasion, minimize Helicobacter‐induced epithelial damage and reduce the risk of gastric ulcer.