Search PubMed⌕ Search

Biomedical subjects

C S Chim

Publications and source records attributed to C S Chim.

121 records · Page 7Linked to original sources
PubMed1997

Primary cardiac lymphoma.

Primary cardiac lymphoma is a rare entity. We report on the clinicopathological features of 2 patients with primary cardiac lymphomas: one involving the right atrium resulting in intractable right heart failure, and the other involving the pericardium with massive pericardial effusion. In the first patient, sternotomy and surgical biopsy of the tumor were performed to arrive at the diagnosis. In the second patient, CT thorax and transesophageal echocardiography helped to diagnose the pericardial tumor, and cytological examination of the pericardial fluid established the pathological diagnosis of lymphoma. Combination chemotherapy (COPP) was started in both patients. The first patient died on the first day of chemotherapy due to intractable heart failure, while the second attained a partial response to chemotherapy but died of progressive disease 8 weeks later. This is followed by a literature review of 21 patients with primary cardiac lymphoma. In conclusion, the prognosis of primary cardiac tumor remains poor.

Aged↗
PubMed1997

Polycythemia vera in Chinese patients: thirty-six years of experience.

Forty-one patients with polycythemia vera (PV) according to the PVSG criteria were analysed retrospectively from January 1960 to March 1996. There were 23 male and 18 female patients with a median follow-up of 66.5 months (3-431 months). Median age was 62 (range: 37-85). The median hemoglobin level at diagnosis was 18.8 g/dl. Four patients were treated by venesection alone, 20 patients received hydroxyurea and intermittent venesection, 3 were treated with radioactive phosphorus alone, and 14 had both hydroxyurea and radioactive phosphorus. During the course of illness, 14 patients (34%) developed a total of 19 thrombotic events. Of the thrombotic events, 16 were arterial and 3 were venous. Two patients had both arterial and venous thrombosis sequentially. The probability of thrombosis-free survival after treatment was 83% at 10 years and 73% at 20 years. One patient developed post-polycythemic myeloid metaplasia 24 months after diagnosis. Of 17 patients exposed to radioactive phosphorus, only 1 developed secondary acute myeloid leukemia (AML) 9 years afterwards. Of the 20 patients treated with hydroxyurea for a median duration of 63.5 months (2-130 months), there is no case of secondary malignancy. Overall survival was 83% at 10 years and 62% at 20 years. In conclusion, PV in Chinese is a relatively benign disease with a low risk of thrombosis as compared to Caucasian patients. Hydroxyurea has a very low risk of secondary leukemia and is a safe drug to use in Chinese patients with PV.

Adult↗
PubMed1997

Improved treatment outcome in adult acute lymphoblastic leukemia using the intensive German protocol, a preliminary report.

Thirty-nine consecutive patients with acute lymphoblastic leukemia were treated with an intensive chemotherapy protocol. There were 23 males and 16 females with a median age of 37 years (range: 15-65). Eighteen patients had common ALL, seven had pre-B ALL, three early-precursor B ALL, seven T-ALL and four had aberrant expression of myeloid antigens (c-ALL in three and pre-B ALL in one). The median initial leukocyte count was 11.8 x 10(9)/l (range: 0.65-295). Cytogenetic result of the marrow was available in 16 of 39 patients (41 per cent) and showed Philadelphia positivity in six, a normal result in six and one each of t(4,11), t(1,19), hyperdiploidy and del 12p. Hepatosplenomegaly was present in about 20 per cent of the patients. L-Asparaginase-related hepatic toxicity was the commonest toxicity (48.7 per cent) during phase I of induction. Prolonged pancytopenia and hypoplastic death were common during phase II. With the use of growth factors during the neutropenic period of phase II induction, the rate of hypoplastic death was reduced from 40 per cent to 3 per cent. Common causes of treatment failure included early hypoplastic death (27.8 per cent) and leukemia relapses (50 per cent) while primary refractory leukemia, hepatic failure and perforated peptic ulcer contributed to 11.1, 5.5 and 5.5 per cent of the other deaths. A high complete remission (CR) rate (87.4 per cent) was achieved after phase I induction. The median event-free survival (EFS) was 8 months and the 3-year event-free survival was 43 per cent. This result compared favourably to the other regimens previously employed in our institution. In conclusion, satisfactory survival can be achieved with this intensive regimen. Good supportive care was however, essential to minimize toxicities.

Adolescent↗
PubMed1997

Autologous bone marrow transplantation for primary nasal T/NK cell lymphoma.

Primary nasal T or NK cell lymphoma is rarely seen in the Western population but is more common in the Orientals. Although it often presents with localized disease, the prognosis is generally poor. Long-term remission is seen in only 50% of patients with stage I disease despite aggressive treatment with chemotherapy and radiotherapy, and is invariably fatal if disseminated. Conventional chemotherapy for relapsed disease is usually not successful. Since 1992, three patients with relapsed primary nasal T/NK cell lymphoma have received high-dose chemotherapy with autologous bone marrow rescue at Queen Mary Hospital, Hong Kong. High-dose cyclophosphamide, BCNU and etoposide were used for conditioning. Two of them had a favourable response and remained in complete remission at 12 and 44 months post-transplant. The third patient unfortunately had a systemic relapse 6 months after the transplant. It appears from this experience that, like other aggressive non-Hodgkin's lymphomas, high-dose chemotherapy and autologous bone marrow rescue is an effective treatment for relapsed primary nasal lymphoma following failure of conventional chemotherapy and radiotherapy.

Adult↗
PubMed1997

CD56+ NK lymphomas: clinicopathological features and prognosis.

The surface molecule CD56 marks a category of malignant lymphoma of putative natural killer (NK) cell origin. We conducted a retrospective analysis of 24 cases of CD56+ NK lymphoma/leukaemia to define the clinicopathologic and prognostic features of this specific group of lymphomas. 56 cases of nasal lymphomas and 204 cases with an initial diagnosis of peripheral T-cell lymphoma were retrospectively analysed. To specifically examine lymphomas of putative NK origin, only those that were negative for surface expression of CD3 but positive for CD56 were analysed. 24 cases were identified. The initial predominant sites of involvement were nasal (n = 18), palate (n = 1), nodal (n = 1) and multi-organ (n = 4). Clinically, in patients with disease localized to one anatomical site (n = 20), most had symptoms confined to the nose, with a high percentage in early stage (I: 91%; IV: 9%). The marrow was not involved in any of these cases. However, patients with multi-organ involvement at presentation (n = 4) behaved differently. All presented acutely with pancytopenia, hepatosplenomegaly, and marrow infiltration with haemophagocytosis. A leukaemic phase was observed in one case. Anthracycline containing combination chemotherapy resulted in complete remission in 75% of patients with localized disease, but only in 25% with multi-organ involvement. The median survival of patients with localized disease was 12 months, compared with 2 months in the multi-organ group (P = 0.06); the disease-free survival was significantly better in the former (P < 0.01). The overall median survival of all patients was still poor at 11 months. We conclude that CD56+ NK lymphomas could be divided into two main patterns of disease presentations: localized (predominantly nasal), and multi-organ involvement. Each has different clinicopathologic and prognostic features. Conventional chemotherapy appeared ineffective for the majority of patients, and innovative treatment modalities are needed to improve outcome.

Adolescent↗
PubMed1996

All-trans retinoic acid (ATRA) in the treatment of acute promyelocytic leukemia (APL).

Acute promyelocytic leukemia is characterized by the reciprocal translocation of chromosomes 15 and 17. All-trans retinoic acid (ATRA) efficiently induces differentiation of the abnormal promyelocytes. In this study, we had used ATRA as the primary induction therapy for 17 newly diagnosed patients, and as the salvage therapy for 11 patients who relapsed from or were resistant to chemotherapy. All patients received subsequent consolidation chemotherapy. Complete remission (CR) rate, early death rate (within 28 days of diagnosis) were then compared to an historical control of 50 APL patients treated with combination chemotherapy; and event-free survival of the 17 newly diagnosed patients was compared to the historical control. In the ATRA group, 26 of the 28 patients (93 per cent) attained complete remission. Two of 28 (7 per cent) died within 28 days of ATRA therapy. There was no case of primary resistance to ATRA. Combination chemotherapy was added to ATRA in five patients due to rapidly increasing leucocyte count. There was one case of retinoic acid syndrome which resolved with steroid. When compared to the 50 cases of historical control, there is significant improvement in the overall CR rate (92 per cent versus 59 per cent, p = 0.001) and a significant reduction in the early mortality rate (7 per cent versus 41 per cent, p = 0.001). Moreover, when the survival result of the 17 newly diagnosed patients were compared with the control, there is a significant improvement in the projected EFS at 3 years (64 per cent versus 25 per cent, p = 0.007). In conclusion, ATRA was shown to improve the CR rate, reduce induction mortality and significantly prolong the event-free survival.

Adolescent↗
PubMed1996

Primary B cell lymphoma of the mediastinum.

Primary B cell mediastinal lymphoma has been recognized as a distinct entity recently. This is a retrospective study to define the clinical features and treatment outcome over a 10-year period. Twenty-four consecutive patients (male/female: 11/13) with B cell lymphoma primarily involving the mediastinum were studied. The median age was 34 years. Symptoms were mainly referrable to the chest, with superior vena cava syndrome (SVCO) present in one-third of the patients. Bulky disease was present in over half (58 per cent) and B symptoms were present in 38 per cent of patients. The overall CR rate was 70 per cent and the 5-year OS rates were 56 per cent and 72 per cent for all and CR patients respectively. Five (71 per cent) primary refractory patients and four (66 per cent) relapsed patients died despite salvage therapy. Six relapses occurred at a median of 6 months from treatment. This study showed that primary large B cell lymphoma of the mediastinum is a clinically distinct entity affecting young patients. A significant proportion attained CR and overall, more than half achieved prolonged remission, and most of the relapses occurred early. However, those who failed to attain CR or relapsed still had a poor outcome. An intensive therapy such as autologous bone marrow transplant has to be considered in this subgroup of patients.

Adolescent↗
PubMedDate not supplied

Can defects in transferrin receptor 2 and hereditary hemochromatosis genes account for iron overload in HbH disease?

Iron overload was found to be the major cause of disability in Chinese HbH disease patients although they were not on regular blood transfusion. The transferrin receptor 2 (TFR2) and hereditary hemochromatosis (HFE) genes were examined to see if inheritance of these gene defects may be a possible cause of iron overload in 45 HbH patients. A novel intronic (IVS6 (+6) T-->A) mutation of the TFR2 gene was identified in one patient, and six others were found to carry a known missense mutation (exon 5, I238M) that was also present in one normal control subject. One HbH patient and one normal control carried the H63D mutation of the HFE gene. Since only eight out of 45 iron-overloaded HbH patients carry a defect in the TFR2 or HFE gene in the heterozygote state and their iron loading status was comparable to the matched controls without such defects, it would appear that the accumulation of excess iron in HbH disease is more likely a result of increase dietary absorption secondary to ineffective erythropoiesis.

Alleles↗