Useful Application of Immunostaining to Malignant Pleural Effusion among Lao People in Vientiane Capital, Lao PDR

Abstract

Background: Pathology and laboratory medicine (PALM) services are limited in low-resource countries, such as<br />Lao PDR. Patients with malignant pleural effusion (MPE) are not properly diagnosed and treated in these situations.<br />The purpose of this study is to confirm the usefulness of immunocytochemistry in MPE to identify the histological<br />type and probable primary site of cancer of MPE and to discuss its usefulness in low-resource countries, such as Laos.<br />Methods: We retrospectively reviewed glass slides of pleural effusion sent to the Department of Pathology at the<br />University of Health Sciences from the central hospitals for cytological screening from January 2012 to December<br />2016. The cytological review, cell transfer and immunocytochemical staining were performed at Tokyo Medical and<br />Dental University. Among 81 cases of MPE from Laos, 66 cases of malignant tumors that contained enough tumor<br />cells were included in this study, and the slides were screened with 14 primary antibodies to classify the histological<br />type and identify the probable primary site of carcinoma. Results: Among the 66 cases, 34 cases (52%) were of female<br />patients, and 32 cases (48%) were of male patients. The patients' ages ranged from 28 to 88 years with an average of 58<br />years. The immunocytochemical study identified 32 cases (49%) of primary lung adenocarcinoma, two cases (3%) of<br />malignant mesothelioma, one case (1.5%) of breast/gynecological carcinoma, one case (1.5%) of T cell lymphoma, and<br />one case (1.5%) of B cell lymphoma. Twenty-nine cases (43.5%) were classified as carcinoma not otherwise specified.<br />Pulmonary small cell carcinoma/squamous cell carcinoma and metastatic colon, prostate, and liver carcinoma were not<br />identified among the cases. Conclusions: Immunocytochemistry is a useful ancillary method in MPE diagnostics. This<br />method could be applied in the pathological laboratories in low- or middle-resource countries, such as Laos.