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Biomedical subjects

J K Chan

Publications and source records attributed to J K Chan.

At least 271 records · Page 15Linked to original sources
PubMed1990

Follicular immunoblastic lymphoma: neoplastic counterpart of the intrafollicular immunoblast?

B-immunoblasts, the precursors of plasma cells, occur predominantly in the interfollicular regions of lymphoid tissue, but may also occur in small numbers in germinal centres (intrafollicular immunoblasts). We report an unusual case of de novo follicular lymphoma composed of immunoblasts with an appreciable amount of plasmacytoid cytoplasm. We postulate that follicular immunoblastic lymphoma probably represents the neoplastic counterpart of the intrafollicular immunoblast.

B-Lymphocytes↗
PubMed1990

Papillary carcinoma of thyroid: classical and variants.

Papillary carcinoma, the commonest primary cancer of thyroid, exhibits a broad morphological spectrum. In this review, the clinicopathological features of papillary carcinoma, classical and its variants (follicular, solid, cribriform, variant with exuberant nodular fasciitis-like stroma, encapsulated, diffuse sclerosing, diffuse follicular, tall cell, columnar cell, oxyphil cell, "dedifferentiated", occult, latent and microcarcinoma) are summarized.

Carcinoma, Papillary↗
PubMed1990

Cribriform variant of papillary thyroid carcinoma.

We report a case of papillary carcinoma of the thyroid exhibiting unusual cribriform structures. The thyroid origin of the tumor was confirmed by positive immunostaining for thyroglobulin.

Adenocarcinoma↗
PubMed1990

Relationship between high-grade lymphoma and low-grade B-cell mucosa-associated lymphoid tissue lymphoma (MALToma) of the stomach.

The distinctive low-grade B-cell mucosa-associated lymphoid tissue lymphoma (MALToma) of the stomach has been well characterized in recent years, but its relationship with the more commonly occurring large B-cell gastric lymphoma has not been clarified. This study aimed to elucidate their relationship. Among 48 consecutive cases of primary malignant lymphoma found in gastrectomy specimens, there were 10 cases showing coexistence of these two elements, which were further studied in detail. The high-grade component predominated in six cases, the low-grade component predominated in two cases, and the two components were intermingled in two cases. In the low-grade component, the small neoplastic cells possessed irregular nuclei (centrocytelike), and glandular invasion was a prominent feature. In the high-grade component, the blasts occurred in clusters or sheets, and often possessed plasmacytoid cytoplasm; glandular invasion was a rare event. In both components, the neoplastic cells frequently showed formation of nodules suggestive of colonization of reactive lymphoid follicles. Immunohistochemical studies showed that the neoplastic cells in the low- and high-grade components expressed the same class of immunoglobulin light chain in eight of the nine cases studied; staining in one case was unsatisfactory. Their intimate relationship as well as identical light chain restriction suggests that the high-grade component arises through blastic transformation of the low-grade component.

B-Lymphocytes↗
PubMed1989

A fatal case of multicentric Kikuchi's histiocytic necrotizing lymphadenitis.

Kikuchi's histiocytic necrotizing lymphadenitis (Kikuchi's disease) is a histologically alarming but self-limiting lesion typically affecting the cervical lymph nodes of young adults. The authors report the first case of fatality occurring during the active phase of Kikuchi's disease. The 38-year-old patient presented with fever and generalized lymphadenopathy. During hospitalization, he developed abrupt onset of heart failure and died. Postmortem examination revealed enlarged lymph nodes all over the body showing typical histologic changes of Kikuchi's disease, but there was no encroachment on vital structures. The heart was dilated and flabby, with multiple microscopic foci of necrosis and mild fatty change. There were no other significant findings, and all cultures were negative. The authors speculate that large amounts of cytokines produced by the histiocytes or high endogenous catecholamines resulting from the stress response might be responsible for the myocardial damage. Alternatively, infection by an as yet uncharacterized microbial might be the underlying cause for both the lymphadenitis and myocardial disease.

Adult↗
PubMed1989

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 Hodgkin's disease. Careful morphologic evaluation and immunophenotypic studies using leukocyte antibodies reactive in paraffin-embedded sections are of great assistance in determining a diagnosis.

Adolescent↗
PubMed1989

Endocrine cell hyperplasia of the uterine cervix. A precursor of neuroendocrine carcinoma of the cervix?

A 33-year-old woman who presented with vaginal bleeding was diagnosed to have neuroendocrine small cell carcinoma based on cervical smear and biopsy. Hysterectomy was performed, and a tumor measuring 5.5 X 2 mm was found at the squamocolumnar junction of the uterine cervix. In the immediate vicinity of the tumor, there was proliferation of cytologically benign endocrine cells in the normal endocervical glands and in the glands showing intraepithelial glandular neoplasia. Both the hyperplastic endocrine cells and the invasive tumor cells showed argyrophilia and immunostaining for neuron-specific enolase, neurofilament, and chromogranin. The topographical relationship suggests that endocrine cell hyperplasia may represent a precursor of neuroendocrine carcinoma of the cervix.

Adult↗
PubMed1989

Lymphadenopathy of Kimura's disease.

Kimura's 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 Kimura's 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 Kimura's 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 Kimura's 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.

Adolescent↗
PubMed1989

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

Although Kimura's 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 Kimura's disease occurring in the Chinese population. The epithelioid haemangiomas occurred in the subcutaneous tissue, skin and maxillary antrum, whereas Kimura's 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 Kimura's 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 Kimura's disease is primarily an inflammatory condition in which high endothelial venules are usually found.

Adult↗
PubMed1989

Clear cell rhabdomyosarcoma of the nasal cavity and paranasal sinuses.

This report describes two cases of alveolar rhabdomyosarcoma of the nasal cavity with unusual histological appearances mimicking clear cell carcinoma. The closely packed tumour cells were polygonal and arranged in sheets and packets. They had an appreciable amount of clear cytoplasm due to accumulation of glycogen. The diagnosis of rhabdomyosarcoma was confirmed by positive staining for desmin and myoglobin. Rhabdomyosarcoma should be included in the differential diagnosis of nasal clear cell tumours, particularly in young adults. A correct diagnosis is important, because chemotherapy is indicated even for apparently localized disease.

Adult↗
PubMed1989

Anaplastic large cell Ki-1 lymphoma. Delineation of two morphological types.

This report describes 16 cases of the recently recognized anaplastic large cell Ki-1 lymphoma. The disease showed a male:female ratio of 2.2:1 and a bimodal age distribution with peaks in the third and eighth decades. The clinical presentation was highly variable, with lymph node, skin, bone and gastrointestinal tract being the most commonly affected sites. The lymph nodes usually showed subtotal or sinusoidal involvement, and parenchymal fibrosis was common. The large neoplastic cells were almost invariably admixed with many reactive small lymphocytes, histiocytes and/or neutrophils. Two cytological types could be delineated: type I (pale cell, four cases) consisted of large polygonal cells with distinct pink-staining cell membrane and pale cytoplasm and pleomorphic nuclei showing marked chromatin clearing; and type II (basophilic cell, 12 cases) consisted of round or oval cells with basophilic cytoplasm and/or paranuclear pale hof, pleomorphic nuclei often reniform or lobulated and with frequent multinucleated wreath-like and Reed-Sternberg-like cells. Immunohistochemical studies showed that nine cases (56.3%) exhibited a T-cell phenotype, three cases (18.8%) each exhibited a B-cell or null-cell phenotype, while one case exhibited both T- and B-cell markers. Cutaneous involvement at presentation was associated with a favourable outcome, and spontaneous regression was common. For patients with non-cutaneous presentation, the prognosis was relatively good for young patients treated with aggressive chemotherapy, but was grave for old patients.

Adolescent↗