Necropsy and clinical data show that primary hepatocellular carcinoma (PHC) is the commonest cancer among the Senoi (a Malaysian aboringine group). The other aboringine tribes do not appear to have this high predilection for liver cancer. In the necropsy series, PHS was present in 10 out of 22 Senoi patients with cirrhosis. All the 22 livers contained hepatocytes that stained with Shikata's orcein stain and specific immunoperoxidase and immunofluorescent stains for hepatitis B antigen (HBAg). This observation raises the strong possibility that hepatitis B may be an important etiologic factor in the development of cirrhosis and PHC in the Senoi. The reason for the high susceptibility of the Senoi for HB virus infection is not clear, and the role of aflatoxin in the pathogenesis of PHC in the Senoi has yet to be determined. That the Senoi are a numerically small community, maintaining their own unique dietary and social customs and living in readily accessible areas in the Malaysian jungle, makes them an ideal population for the study of factors in the etiology of liver cancer.
Necropsies were performed on 285 consecutively unclaimed Orang Asli bodies from Gombak Orang Asli Hospital during an eight-year period from May 1967 to April 1975. Of the 25 malignant neoplasms, hepatocellular carcinoma was by far the commonest (36%). The nine patients with this neoplasm had coexistant macronodular cirrhosis. There were 20 cases of cirrhosis; 45% of these had coexistant hepatocellular carcinoma. The 53,000 Orang Aslis living in West Malaysia comprise three tribes, the Negrito, Senoi, and Melayu Asli (Proto Malays). The Sinoi appear to have a high predilection for liver cancer, all our nine cases occurring in this group. These aboriginal people live in the jungles where they practice shifting cultivation and maintain their own dietary and social customs. Detailed studies of their dietary habits may provide a clue to the etiology of liver cancer in these people.
A ten-year review revealed a similarity in the incidence of teratoma in relation to other childhood tumors in Malaysian as compared with Caucasian children. The most common sites of origin were the sacropcoccygeal, gonadal, and retroperitoneal areas. The reason for the high incidence of retroperitoneal tumor in our series as compared with other countries is not clear. Late presentation and poor followup are associated with poor prognosis.
Adequately biopsied renal tissue received in the Department of Pathology, University Hospital, Kuala Lumpur from 1,000 consecutive Malaysian patients during an eleven year period between 1970 and 1981 was reviewed. The youngest patient was 6 days old and the oldest 80 years. Both sexes were equally represented. The majority of the patients were Chinese (71%) with Malays and Indians comprising most of the remainder. Over half the patients (50.4%) presented with the nephrotic syndrome. Other modes of presentation included systemic lupus erythematosus, proteinuria and haematuria separately or in combination and hypertension. Minimal change (25.7%) and proliferative glomerulonephritis (24.8%) were present in about equal numbers and together accounted for over half of the cases (50.5%). Lupus nephritis was the third most common diagnosis (18.4%). In addition, there were patients with focal glomerulonephritis (5.4%), membranous glomerulonephritis (5.5%), Berger's disease (5.8%), amyloidosis (0.6%) and end stage renal disease (4.0%).
Twenty children with retinoblastoma are reviewed who were treated at the University Hospital, Kuala Lumpur over a 10-year-period. They constitute 6.6% of childhood malignancies and without exception all presented with advanced disease. Hereditary cases were notably absent in the the series probably because past cases have almost invariably succumbed without an opportunity to transmit the gene. With enucleation and radiotherapy six of the patients have survived from 2 to 12 years. The addition of vincristine and cyclophosphamide has not been associated with improved survival.
In view of a high prevalence of hepatitis B virus infection in the Malaysian population, indirect immunofluorescence examination for hepatitis B surface antigen (HBsAg) was routinely performed on renal biopsy specimen at the University Hospital, Kuala Lumpur, over a 3-year period. Examination of renal tissue from 259 patients, including 47 with systemic lupus erythematosus (SLE), revealed 43 cases with HBsAg in glomerular immune complexes. A significantly high proportion (30/43) of these were SLE patients. The deposits were granular in nature, situated in both the capillary walls and mesangium and associated with immunoglobulin deposition. Morphological patterns of lupus nephritis involved were focal proliferative (one case), diffuse proliferative (23 cases) and membranous (six cases). None of these patients showed clinical evidence of liver disease. The significance of these findings remains uncertain, but the possibility exists that the hepatitis B virus may have a role in the pathogenesis of SLE in the tropics where both SLE and HBs antigenaemia are common.
Eight cases of xanthogranulomatous pyelonephritis occurring in an oriental population are reported. The patients were mostly middle-aged, and there was a female preponderence. Nephrectomy controlled the disease in all cases. Diagnosis on clinical and radiological grounds is difficult, and it is often only made on pathological examination of the kidney after nephrectomy. The nature of the disease remains obscure.
Material from 334 consecutive autopsies on Orang Asli subjects performed in the University Hospital, Kuala Lumpur between May 1967 and June 1978 was examined for amyloidosis. Nine positive cases were found, all in patients above 40 years of age, giving an age-corrected incidence of about 9%. In 6 cases, amyloidosis was probably secondary to tuberculosis. The remaining 3 cases exhibited a pericollagenous distribution characteristic of primary amyloidosis. Involvement of the heart and lungs was prominent. However, there were considerable similarities in the distribution and staining properties of the amyloid in the 2 groups. Though both the heart and kidney were frequently affected, the kidney was the most common organ to give rise to clinical symptoms. Infection probably plays a major contributory role in amyloidosis in the Orang Asli.
The ultrastructure of the cyst wall and zoites of a species of Sarcocystis from the skeletal muscles of a naturally-infected Malaysian long-tailed monkey, Macaca fascicularis, is described in detail. The wavy, electron-dense primary cyst wall is thin (55 nm) and invaginated. Cytophaneres are absent. The ground substance contains electron-dense granules and bundles of parallel, fibrillar elements in some areas. Thin trabeculae are present. The zoites measure 1.2 X 4.7 microns and have an interior conoid, 22 subpellicular microtubules, 50-60 micronemes, 4-6 rhoptries, and a posteriorly situated nucleus. Some ultrastructural aspects of the cyst wall and the zoites of this parasite resemble those of Sarcocystis species of the moonrat, rhesus monkey, tamarin, and baboon. The light microscopic appearance of this species from M. fascicularis also bears some resemblance to that of parasites from the four cases of human Sarcocystis reported in Malaysia. The cyst in all these human cases were thin-walled, with no cytophaners. Although the final hosts of these species of Sarcocystis are not known, it is quite possible that man, monkeys, and perhaps the moonrat (an insectivore) may serve as common intermediate hosts for one or several species of Sarcocystis.