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Biomedical subjects

J K Chan

Publications and source records attributed to J K Chan.

At least 289 records · Page 16Linked to original sources
PubMed1989

Optimal formalin fixation and processing schedule of cell blocks from fine needle aspirates.

In fine needle aspiration cytology, cell blocks may provide diagnostic information complementary or additional to that obtained from examination of cell smears. However, the morphological preservation is often unsatisfactory in cell blocks processed by routine schedules used for surgical specimens. This study investigates the effects of different formalin concentrations and processing schedules on cellular morphology. We conclude that 7.5% buffered formalin is the optimal formalin solution and a shortened processing time through xylene is desirable.

Biopsy, Needle↗
PubMed1989

Cutaneous relapse of nasal T-cell lymphoma clinically mimicking erythema multiforme.

Lymphomatous involvement of skin usually manifests as plaques, maculopapules, papulonodules, tumorous masses or ulcerated eruptions. We report an unusual case in which the cutaneous relapse of nasal T-cell lymphoma clinically mimicked erythema multiforme by the abrupt onset of lesions and the presence of targetoid and vesicular lesions. Histologically, the lymphomatous involvement was predominantly periadnexal, with destructive infiltration of blood vessels, nerves and sweat glands. Early biopsy of all unexplained cutaneous eruptions in patients with malignant lymphoma is therefore recommended.

Adult↗
PubMed1989

Nasal astrocytoma or nasal glial heterotopia?

This report describes a unique astrocytic lesion of the nasal cavity that was connected to a frontal lobe astrocytoma via the eroded cribriform plate. The nasal lesion probably resulted from downward extension of the cerebral astrocytoma. Other possibilities included coexistence of nasal glial heterotopia and intracerebral astrocytoma, and nasal glial heterotopia complicated by neoplastic transformation and intracranial extension.

Adult↗
PubMed1988

Comparative histopathology of resected bronchial cancers of women in Hong Kong and Japan.

Pathological findings relating to lung cancers removed surgically from women at the Kowloon Hospital (KH), Hong Kong, and the Cancer Institute Hospital (CIH), Japan (77 and 54 cases respectively), were examined in order to clarify possible differences between Hong Kong Chinese and Tokyo Japanese women. Adenocarcinoma was the most frequent subtype encountered in both hospitals, but the rate was higher in CIH (90.9% in CIH and 68.8% in KH); that of large-cell carcinoma was second in KH where the rate was higher (14.3% in KH and 0%, in CIH). A remarkable difference was observed in the location of adenocarcinomas; the percentages of central and peripheral types were 60.4% and 24.5% respectively in KH, but 4% and 96% respectively in CIH. The proportion of the central type (45.5%) was higher than that of the peripheral type (27.3%) in large-cell carcinomas of KH. The number of adenocarcinomas having a bronchiolo-alveolar pattern (which is observed more frequently in peripheral-type adenocarcinomas) was higher in CIH (50%) than in KH (17%). Tall columnar cells were observed more often in KH (43.1% in KH and 20.8% in CIH), and hobnail and cuboidal cells more often in CIH (31.4 and 80.4% respectively in KH, and 54.2 and 95.8% respectively in CIH). The difference may be explained by the frequent presence of tall columnar cells in the glands of central carcinomas, and hobnail and cuboidal cells in peripheral adenocarcinomas. The frequent occurrence of the central type of adenocarcinoma and large-cell carcinoma appears characteristic of the lung carcinomas removed from women in Hong Kong. This suggests the existence of exogenous causative agents for lung cancer in Hong Kong females.

Adenocarcinoma↗
PubMed1988

Mucin production in metastatic papillary carcinoma of the thyroid.

Although textbooks often state that demonstration of mucin in a metastatic carcinoma excludes the possibility of a thyroidal primary tumor, mucin recently has been reported in various types of thyroid carcinoma, particularly medullary carcinoma. The presence of mucin in papillary carcinoma has not been extensively studied, even though this tumor not uncommonly presents with lymph node metastasis. We stained 40 lymph nodes containing metastatic papillary carcinoma of the thyroid for mucin. Mucin was demonstrable by mucicarmine stain in the colloid, luminal borders, and cytoplasm in 18 (45%), 9 (22.5%), and 7 (17.5%) cases respectively; 17 cases (42.5%) were completely negative. With alcian blue staining, mucin was seen in 9 (22.5%), 9 (22.5%), and 7 (17.5%) cases; 25 cases (62.5%) were negative. Most of the cytoplasmic vacuoles were target-like, with a peripheral rim of sulfated acid mucin and a central core of neutral mucin. The psammoma bodies stained consistently with mucicarmine, alcian blue, and periodic acid-Schiff. We conclude that papillary carcinoma of the thyroid should be included in the differential diagnoses for a mucin-producing metastatic carcinoma.

Adolescent↗
PubMed1988

Monoclonal antibodies reactive with normal and neoplastic T cells in paraffin sections.

Without fresh or frozen tissue, it previously has been impossible to confirm the T-cell nature of reactive or neoplastic lymphoid cells. The availability of antibodies reactive with T cells in paraffin sections now allows retrospective analysis of a large number of cases. Two commercially available monoclonal antibodies, MT1 and MT2, were tested for their reactivities with T cells in a wide range of formalin-fixed, paraffin-embedded tissues, including 130 cases of immunologically characterized lymphoma. In reactive lymph nodes, MT1 stained the T-cell areas, whereas MT2 stained both the T-cell areas and mantle-zone B lymphocytes. MT1 stained 38 of 55 T-cell lymphomas (69.1%; 94.7% of cases from one hospital that used a shorter fixation time, and 55.6% of cases from another hospital that used a longer fixation time). MT2 stained only 6 (10.9%) of the T-cell lymphomas. Among the 74 cases of B-cell lymphoma, 3 (4.0%) were stained by MT1 and 30 (40.5%) by MT2.MT1 was also reactive with 3 of 4 cases of granulocytic sarcoma, as expected from its reactivity with normal granulocytes. Neither MT1 nor MT2 stained Reed-Sternberg cells or their variants in HodgKin's disease. We conclude that MT1 is a valuable marker for T cells, particularly when used with a panel of antibodies reactive with B cells in paraffin sections. MT2 is of limited value because of its cross-reactivity with many B-cell lymphomas.

Antibodies, Monoclonal↗
PubMed1988

Rehydration of air-dried smears with normal saline. Application in fine-needle aspiration cytologic examination.

In fine-needle aspiration cytologic examination, nuclear features are often better assessed in hematoxylin and eosin (H and E) or Papanicolaou- (Pap) stained than Romanowsky-stained smears. However, both H and E and Pap stains require the use of immediately wet-fixed smears for cytomorphologic preservation. Some degree of air drying is usually inevitable. Placing air-dried smears in normal saline for 30 seconds before fixation in 95% alcohol is found to be a simple means of rehydrating the cells. The quality of the rehydrated smears is superior or identical to that of the immediately wet-fixed smears, provided that the period of drying does not exceed 30 minutes.

Biopsy, Needle↗
PubMed1988

Juvenile chronic myeloid leukemia. A malignancy of S-100 protein-positive histiocytes.

Three cases of juvenile chronic myeloid leukemia (JCML) are reported. The patients were aged 3-4.5 years and presented with generalized lymphadenopathy, hepatosplenomegaly, anemia, thrombocytopenia, elevated white blood cell count with monocytosis, and high fetal hemoglobin level. Philadelphia chromosome was absent in two cases studied. The bone marrow showed myeloid hyperplasia with increased monocytoid cells and blasts. Biopsy or postmortem material available in two cases revealed malignant infiltration of lymph nodes, liver, spleen, lungs, intestines, and skin. The neoplastic cells ranged from cells with irregular nuclei possessing nuclear grooves to large blastic cells with round to lobulated nuclei and prominent nucleoli. They showed weak staining for acid phosphatase and nonspecific esterase and exhibited the immunophenotype EBM11+KiM1+KiM6+KiM8+CD4+HLADR+ S-100 protein+. The neoplastic cells of JCML therefore share features of dendritic cells and mononuclear phagocytes. The authors' findings show that JCML is a unique histiocytic malignancy in which S-100 protein is a useful marker.

Blood Cells↗
PubMed1988

Angiocentric T-cell lymphoma of the skin. An aggressive lymphoma distinct from mycosis fungoides.

Among 37 consecutive cases of malignant lymphoma in which the skin was either the only site of disease or one of the prominent sites of initial involvement, 19 cases had a distinctive histological appearance. These cases corresponded to what has been termed "angiocentric lymphoma," and all were found to exhibit a T-cell phenotype either by frozen-section immunohistochemistry or by using monoclonal antibodies reactive in paraffin sections. There were nine men and 10 women; the mean age was 48.2 years. The lesions were nodular and were either ulcerated or had intact skin. One case presented with involvement of one anatomical region of skin, five had involvement of multiple regions of skin, and 13 had concurrent extracutaneous disease. The disease pursued an aggressive course and was not uncommonly resistant to treatment. Histologically, the lymphomatous infiltrate occurred predominantly in the mid to deep dermis with involvement of the subcutaneous layer. The pattern was mainly perivascular and peri-adnexal with or without confluence; the overlying epidermis and papillary dermis were often spared. A prominent feature was invasion of small or large blood vessels by lymphoma cells. Eight cases showed extensive coagulative necrosis of the neoplastic and normal tissues, and 12 cases showed intraneural invasion. The neoplastic lymphoid cells consisted of either a monomorphous population or a variable mixture of small, medium-sized, and large cells with stippled chromatin and distinct nucleoli. Although the nuclei were often irregularly folded, few exhibited a cerebriform configuration. The cytoplasm was pale to clear. These cases exhibit a remarkable histological similarity to the T-cell lymphomas of the nasal/nasopharyngeal region; in addition, there are features that overlap with so-called lymphomatoid granulomatosis of the skin.

Adult↗