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H Samaratunga

Publications and source records attributed to H Samaratunga.

At least 19 recordsLinked to original sources
PubMed2000

Localization of N-acetyltransferases NAT1 and NAT2 in human tissues.

Human acetyl coenzyme A-dependent N-acetyltransferase (EC 2.3.1.5) (NAT) catalyzes the biotransformation of a number of arylamine and hydrazine compounds. NAT isozymes are encoded at 2 loci; one encodes NAT1, formerly known as the monomorphic form of the enzyme, while the other encodes the polymorphic NAT2, which is responsible for individual differences in the ability to acetylate certain compounds. Human epidemiological studies have suggested an association between the "acetylator phenotype" and particular cancers such as those of the bladder and colon. In the present study, NAT1- and NAT2-specific riboprobes were used in hybridization histochemistry studies to localize NAT1 and NAT2 mRNA sequences in formalin-fixed, paraffin-embedded human tissue sections. Expression of both NAT1 and NAT2 mRNA was observed in liver, gastrointestinal tract tissues (esophagus, stomach, small intestine, and colon), ureter, bladder, and lung. In extrahepatic tissues, NAT1 and NAT2 mRNA expression was localized to intestinal epithelial cells, urothelial cells, and the epithelial cells of the respiratory bronchioles. The observed heterogeneity of NAT1 and NAT2 mRNA expression between human tissue types may be of significance in assessing their contribution to known organ-specific toxicities of various arylamine drugs and carcinogens.

Arylamine N-Acetyltransferase↗
PubMed1998

Non-rabies Lyssavirus human encephalitis from fruit bats: Australian bat Lyssavirus (pteropid Lyssavirus) infection.

A 39-year-old woman died of encephalitis a few weeks after being scratched by fruit bats. Autopsy disclosed meningoencephalomyelitis, and revealed neuronal intracytoplasmic inclusions which had similarities to Negri bodies of rabies. Laboratory investigations detected a Lyssavirus type previously identified only in fruit bats. This appears to be the first human case of encephalitis due to this Lyssavirus type.

Adult↗
PubMed1997

Distribution pattern of basal cells detected by cytokeratin 34 beta E12 in primary prostatic duct adenocarcinoma.

Primary prostatic duct adenocarcinoma, initially labeled as endometrioid carcinoma of the prostate, is a rare neoplasm that displays exophytic growth into the prostatic urethra with involvement of prostatic ducts. Because this tumour arises from preexisting epithelia, there is a possibility that a remnant basal epithelium may be seen in association with these tumours. If this hypothesis is correct, then prostatic duct adenocarcinoma may possibly be mistaken for high-grade prostatic intraepithelial neoplasia (PIN) on needle biopsies. The distribution of basal cells in this tumour has not been described previously. Nine cases of prostatic duct adenocarcinoma and prostatic adenocarcinoma with focal ductal differentiation were studied immunohistochemically with antibodies specifying cytokeratin 34 beta E12, prostate-specific antigen (PSA), and prostatic acid phosphatase (PAP). All cases were positive for PSA and PAP. In some areas of the tumour in eight cases there was a continuous and discontinuous layer of basal cells surrounding islands of carcinoma. This was found with cribriform, comedo, solid, and papillary components of ductal type adenocarcinoma. It is necessary to be aware of the presence of basal cells in association with primary prostatic duct adenocarcinoma. Differentiation of high-grade PIN from this lesion should depend on complex architectural characteristics and Cytologic features rather than presence of a basal cell layer. This finding confirms that the solid, cribriform, papillary, and comedo components initially grow intraluminally within ducts before invasion into surrounding stroma occurs.

Acid Phosphatase↗
PubMed1996

Intravascular fasciitis: a case report and review of the literature.

A 49 year old man presented with a mass in the inguinal region that for 3 mths had been associated with slight discomfort. Clinically the mass was thought to be an enlarged lymph node. Histology however showed nodular fasciitis. There was also an associated smaller lesion that was histologically identical and which involved the wall of a medium sized vein with protrusion into its lumen. These appearances were typical of intravascular fasciitis. Review of the Royal Brisbane Hospital Pathology files for 12 yrs from 1982, revealed no other such cases. We describe here the clinical and pathological features of this case and review the literature on this rare condition.

Fasciitis↗
PubMed1996

Mango dermatitis: allergic contact dermatitis to Mangifera indica.

Mango Dermatitis' is the common term given to allergic contact dermatitis to the sap or skin of the fruit of Mangifera indica. Four patients presented with urticaria and eczematous rash following exposure to mangoes or the trees. Patch testing with diluted sap, crushed leaf, crushed stem and fruit skin was strongly positive.

Adult↗
PubMed1996

Nodular fasciitis and related pseudosarcomatous lesions of soft tissues.

BACKGROUND: Nodular fasciitis is characterized by a proliferation of spindle cells which may be misdiagnosed as sarcomas due to the rich cellularity, mitotic activity and variant morphologic patterns. METHODS: This report includes 42 cases of nodular fasciitis and related conditions of skin and soft tissue from the pathology files of the Royal Brisbane Hospital, Queensland, Australia. There were 33 cases of nodular fasciitis, three cases of ossifying fasciitis, three cases of proliferative fasciitis, two cases of proliferative myositis and one case of intravascular fasciitis. Two-thirds of cases were referred from outside Royal Brisbane Hospital. RESULTS: Nodular fasciitis and ossifying occurred most commonly in young adults with 16 patients (44%) between the ages of 20 and 29. However, the other variants of nodular fasciitis including proliferative myositis and intravascular fasciitis occurred in older people (six patients being older than 49 years) and more commonly occurring in men (n=5). A painless rapidly growing mass was most common. The lesions of nodular fasciitis were most often located in the upper extremity with the forearm most commonly affected. CONCLUSIONS: Nodular fasciitis and related conditions are benign. All patients are alive and well 3 months to 13 years (mean 7.2 years) after simple local resection.

Adolescent↗
PubMed1994

Cerebral metastasis of an atrial myxoma mimicking an epithelioid hemangioendothelioma.

A 60-year-old woman presenting with a 15-month history of Jacksonian seizures was found on computed tomography (CT) scan to have an enhancing subcortical lesion high in the left anterior parietal lobe. The excised tumor had light microscopic features similar to those of an epithelioid hemangioendothelioma, and immunohistochemical stains confirmed its vascular nature. At surgery, the patient had no clinical or radiological (including CT body scan) evidence of any other lesion. However, 22 months after symptoms first appeared, she presented with dyspnea and bilateral pleural effusions, and a left atrial myxoma was detected echocardiographically. The histologic features of the resected myxoma were identical to those of the previously excised cerebral lesion, and it became apparent that the intracranial tumor was a metastasis of the atrial myxoma. This case illustrates that before a diagnosis of visceral epithelioid hemangioendothelioma is rendered, the possibility of metastatic occult cardiac myxoma should be considered. Echocardiography is warranted for such patients.

Brain Neoplasms↗
PubMed1994

Squamous cell carcinoma in situ involving mesonephric remnants. A potential diagnostic pitfall.

A case of uterine cervical squamous cell carcinoma in situ (CIS) in which there was extensive endocervical glandular involvement was found to have, in addition, a deep-seated squamous epithelial lesion within the cervical stroma. Because of the deep location of this lesion, which was composed of nests of pleomorphic squamous epithelial cells, found at a site not usually occupied by endocervical glands, it was initially thought to be an invasive squamous cell carcinoma (SCC). However, on review it was found that there was CIS in the deep cervical stroma that appeared to involve small tubular structures and dilated ducts that were lined by mucin-free cuboidal epithelial cells. There was no stromal reaction to this lesion. Tubules had a poorly defined lobular arrangement and had intraluminal bright eosinophilic hyaline material. Tubular epithelial cells demonstrated immunohistochemical staining for low-molecular-weight keratin (LMWK) and vimentin but showed no staining for carcinoembryonic antigen (CEA) and high-molecular-weight keratin (HMWK). It was apparent that these tubular structures and ducts were mesonephric remnants and that this lesion represented involvement of mesonephric remnants by CIS. Although involvement of endocervical glands by CIS is well recognized, a similar lesion involving mesonephric remnants has not been previously described. Familiarity with the histological features of these lesions is essential to avoid a misdiagnosis and potential mismanagement.

Carcinoma in Situ↗
PubMed1993

Human papillomavirus DNA in glandular lesions of the uterine cervix.

AIMS: To assess the role of human papillomavirus in the pathogenesis of adenocarcinoma in situ, endocervical glandular dysplasia (a presumed precursor of adenocarcinoma) and endocervical glandular epithelial giant cell change. METHODS: Viral detection was carried out using an in situ hybridisation technique on paraffin wax sections. Biotinylated probes for human papillomavirus types 6/11, 16/18, 31/33/35 were used with a colorimetric detection system. RESULTS: Nine out of 21 (43%) cases of adenocarcinoma in situ contained human papillomavirus types 16/18, one of which was also positive for 31/33/35. Ten cases of glandular dysplasia and four cases of glandular epithelial multinucleation did not react with the probes used. CONCLUSIONS: These results indicate that while adenocarcinoma in situ is strongly associated with human papillomavirus infection, endocervical glandular dysplasia and glandular epithelial multinucleation are probably not associated with the virus.

Adenocarcinoma↗
PubMed1992

Value of fine needle aspiration biopsy cytology in the diagnosis of discrete hepatic lesions suspicious for malignancy.

Ninety-five sequential computerized tomography (CT) guided fine needle aspirates (FNA) of the liver, taken between January 1986 and December 1989 were reviewed to assess the accuracy of this method in diagnosing discrete hepatic lesions suspicious for malignancy. Clinical follow-up information, or a tissue diagnosis or both were available in 71 of these cases. False-negative results were found in four of the cases. Forty-six cases in the group gave a positive result with FNA and confirmatory tissue diagnosis was made in 25 of these cases. Detailed clinical follow-up produced additional support for the diagnosis in 20 other cases. Twenty-four cases were negative but clinical follow-up indicated that there were four false-negative diagnoses. The one false-positive case in this series was diagnosed as a hepatocellular carcinoma in a patient with haemochromatosis. Overall, the results gave a sensitivity of 90% and a specificity of 87%.

Adult↗
PubMed1991

Squamous cell carcinoma arising in a case of vulvitis granulomatosa or vulval variant of Melkersson-Rosenthal syndrome.

A case of vulvitis granulomatosa or the vulval variant of Melkersson-Rosenthal syndrome (MRS) in a young adult patient with systemic lupus erythematosus is presented. She also had evidence of cervicovulvovaginal human papilloma virus (HPV) infection. Nine years later she developed a squamous cell carcinoma (SCC) of the vulva. HPV 6/11 was found by DNA in situ hybridization within a vulval condyloma as well as within the carcinoma. This case is unusual in that SCC associated with HPV 6/11 developed in her vulva affected by MRS rather than in the cervix, where SCC was more likely to occur considering this patient's age.

Adult↗
PubMed1991

A clinicopathological study of adenocarcinoma in situ of the cervix. The influence of cervical HPV infection and other factors, and the role of conservative surgery.

Adenocarcinoma in situ (ACIS) of the uterine cervix is an increasingly recognized disease. Thirty-seven cases were reviewed to determine the effect of HPV, marital status, parity, smoking habit and age on the topography and behaviour of this lesion. Using a commercial probe, 25% of 28 lesions tested were positive for HPV 16/18. The presence of HPV and a history of smoking appeared to exert no significant influence upon the topography and behaviour of ACIS. Nulliparity and a history of never being married was associated with a significant reduction in the incidence of coexisting CIN lesions. Age less than 36 years was associated with a significant reduction in the proximal linear extent of ACIS. While hysterectomy is probably the definitive treatment for ACIS of the cervix, there is an important place for conservative management by conization alone. Patients younger than 36 years are most likely to be desirous of retained fertility and appear to have the lesions most amenable to conservative surgery.

Adenocarcinoma↗