Detection of B cell lymphoma involvement in T cell-rich serous fluid by immunoglobulin gene rearrangement: a report of 2 cases

BACKGROUND: Cytology, flow cytometry and gene rearrangement studies are methods to detect lymphoma involvement of body fluid. The cytology of the effusion is equivocal for lymphoma involvement. CASES: We report 2 cases of diffuse large B cell lymphoma with massive lymphocyte predominant serous fluid, ascites in one case and pleural effusion in the other. Immunophenotypic analysis by flow cytometry showed that lymphoid cells express only T cell markers. Lymphoma involvement of effusion was confirmed by immunoglobulin gene rearrangement detected by polymerase chain reaction. CONCLUSION: Our case demonstrated the value of gene rearrangement study in establishing diagnosis of equivocal cases.     

Cytomorphologic diagnosis of malignant lymphoma arising in the heart: a case report.

BACKGROUND: Primary malignant lymphoma of the heart is extremely rare. Because its clinical signs and symptoms are typically nonspecific, it is often very difficult to detect cardiac involvement while the patient is alive. We describe a case of malignant lymphoma involving predominantly the heart and pericardium and diagnosed by pericardiac effusion cytology antemortem. CASE: An 83-year-old woman presented with dyspnea on exertion. Echocardiography revealed a low-echoic tumor mass close to the right ventricular wall and massive pericardiac effusion. Diagnosis of diffuse large B-cell lymphoma was made by cytomorphologic examination and flow cytometry of the tumor cells obtained from the effusion. Although chemotherapy was instituted immediately, the patient died of progressive heart failure. Diffuse large B-cell lymphoma predominantly involving the intracardiovascular region was confirmed at autopsy. CONCLUSION: From the experience in this case, we conclude that cytopathologic examination of sonographically guided aspiration of the cardiovascular region is very useful for antemortem diagnosis of primary malignant lymphoma of the heart.     

Pleural effusions in non-Hodgkin's lymphoma. A cytomorphologic, cytochemical and immunologic study

Review of the records of 243 cases of cytologically diagnosed non-Hodgkin's lymphomas (NHL) revealed pleural effusions in 21 (8.6%). Cytologic examination of pleural fluid was done in 17 cases, of which 16 were reported as positive. Cytologic examination was supplemented with cytochemical staining (acid phosphatase, alpha naphthyl acetate esterase and periodic-acid-Schiff reactions) and E-rosetting studies in 12 cases. Of the 16 positive cases, 11 were malignant lymphomas consisting of convoluted lymphocytes. Acute lymphatic leukemia of the prothymocytic type (T-ALL) and chronic lymphocytic leukemia of the T-cell type (T-CLL) comprised one case each, and there were three cases of follicular center cell lymphomas, two of the cleaved-cell type and one of the Burkitt-type. Comparison of the cytomorphology of the tumor cells in the pleural effusion with those in fine needle aspiration smears from the solid tumors in 14 cases showed an identical appearance in 13 cases; in one, the Burkitt-type lymphoma, the cells were larger and more pleomorphic in the pleural effusion. This study indicates that the cytologic diagnosis and categorization of NHL of the convoluted-cell type is greatly enhanced by the study of neoplastic lymphocytes in a pleural effusion.     

Primary effusion lymphoma. A case report

BACKGROUND: Primary effusion lymphoma (PEL) is a rare type of lymphoma that presents as an effusion, seldom with evidence of a solid neoplasm elsewhere; thus, cytology is the basic diagnostic method. It usually occurs in HIV-positive males with a history of Kaposi's sarcoma (KS), and DNA sequences of human herpesvirus 8 (HHV-8) are detected by molecular analysis. The distinct morphologic, immunophenotypic, molecular and clinical characteristics render this neoplasm a new pathologic entity. CASE: A 57-year-old, HIV-positive man presented to the hospital with ascites and absence of neoplasm on radiologic investigation. Cytologic evaluation of the ascitic fluid revealed the presence of highly atypical, pleomorphic lymphoid cells. Immunocytochemistry of the lymphoma cells was positive for CD45 (leukocyte common antigen), CD30 and epithelial membrane antigen antigens and negative for panB, panT and cytokeratin antigens. DNA sequences of HHV-8 were identified by polymerase chain reaction (PCR), and DNA ploidy analysis showed aneuploidy. The patient died 5 months after the diagnosis. CONCLUSION: Conventional and ThinPrep (Cytyc Corp., Boxborough, Massachusetts, U.S.A.) cytology, in combination with immunocytochemistry and PCR for HHV-8 DNA sequences, can lead to an accurate diagnosis of PEL. DNA ploidy analysis confirms the aggressive nature of this neoplasm.     

AIDS-related body cavity-based lymphoma. A case report

BACKGROUND: Body cavity-based lymphomas are rare malignancies in human immunodeficiency virus (HIV)-infected patients, but because of their unusual clinical, morphologic and immunophenotypic features, they are recognized as a distinct subgroup of lymphomas connected to human herpesvirus 8 (HHV-8) infection. CASE: A 39-year-old, HIV-positive, homosexual man was admitted to the hospital because of a left-sided pleural effusion that contained malignant lymphoid cells. He responded partially to a low-dose cyclophosphamide/doxorubycin/vincristine/prednisone regimen and died five months after the diagnosis of lymphoma. On cytology, the sediments contained exclusively large, round, neoplastic, lymphoid cells with abundant basophilic cytoplasm and large, round nuclei with prominent nucleoli. Many cells had immunoblastic features, and some had plasmocytoid differentiation. Mitotic figures were numerous. On flow cytometry, the homogeneous population of large cells expressed CD45, CD38, HLA-DR and CD7 positivity. Other specific T-, B- and NK-cell markers tested negative. Polymerase chain reaction demonstrated Epstein-Barr virus (EBV) and HHV-8 in the malignant effusion. CONCLUSION: Primary effusion from lymphoma with molecular evidence of HHV-8 and EBV coinfection represents a distinct clinical and morphologic entity in AIDS patients. However, immunophenotypic markers of malignant clones can be diverse in different cases.     

Primary cardiac lymphoma initially diagnosed by routine cytology. Case report and literature review

A case of primary cardiac lymphoma initially diagnosed by routine cytologic examination of pericardial fluid is presented. In a 64-year-old woman woman who originally presented with chest pain and heart block, the initial clinical impression was ischemic heart disease. However, coronary angiography failed to reveal significant disease. An echocardiogram demonstrated pericardial fluid, which was drained. A small amount was sent for cytologic examination, and the diagnosis of malignant lymphoma, large cell type, was made. Subsequent radiologic examinations revealed an intracardiac mass involving the atrioventricular canal; surgical biopsy confirmed the diagnosis of a large cell lymphoma. While primary malignant lymphoma of the heart is rare, this case highlights the efficacy of routine cytologic examination of an effusion fluid (often drained therapeutically) in establishing the correct diagnosis.     

恶性肿瘤胸腹水细胞学检验的探讨

目的探讨胸腹水细胞学检验在恶性肿瘤细胞诊断中的应用价值。方法回顾我院2014年1月~2016年6月376例胸腹水脱落细胞学的检验结果,分析胸腹水细胞学检验在恶性肿瘤诊断中的应用价值。结果 376例胸腹水脱落细胞学检验患者中,发现疑似肿瘤细胞3例,恶性肿瘤细胞74例,病理组织学证实恶性肿瘤患者79例,胸腹水细胞学检验的正确率高达97.47%,假阴性率为2.53%,假阳性率为0%。结论胸腹水脱落细胞学检验在恶性肿瘤诊断中具有重要的临床价值,值得临床推广。     

Human herpesvirus 8 in primary effusion lymphoma in an HIV-seronegative male. A case report

BACKGROUND: AIDS-related body cavity-based lymphoma, or primary effusion lymphoma (PEL), is a distinct clinicopathologic entity that occurs predominantly in immunosuppressed patients infected with human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma-associated herpesvirus. Although it rarely occurs in human immunodeficiency virus (HIV)-negative patients, we report such a case here. CASE: A 74-year-old male, who was HIV and Epstein-Barr virus (EBV) negative, was admitted to the hospital with dyspnea and chest pain. Chest radiography and computed tomography showed right pleural effusion. Cytologic analysis of the pleural effusion revealed a high grade lymphoma with round nuclei, prominent nucleoli and abundant cytoplasm. Polymerase chain reaction performed on the pleural effusion was positive for HHV-8 and negative for EBV. On molecular studies, the immunoglobulin heavy and kappa light chains were rearranged. Flow cytometry revealed a hyperploid fraction with DNA index of 1.29 expressing CD30. Immunostaining for HHV-8 from a cell block was positive. Electron microscopy revealed lymphomalike cells, many in various stages of apoptosis, with large nucleoli and clusters of viruslike particles in the nucleoplasm. CONCLUSION: A firm diagnosis of PEL can be established by the examination of cells from the lymphomatous effusion by a combination of cytology, molecular genetics, phenotypic features, immunostaining and electron microscopy. To our knowledge, this is the first case in which immunostaining for anti-HHV-8 monoclonal antibodies was used to support the diagnosis.     

Cytomorphological and immunocytochemical study of non-Hodgkin's lymphoma in pleural effusion and ascitic fluid

INTRODUCTION: Non-Hodgkin's lymphoma (NHL) is often complicated by pleural effusion and ascites. The present study is an attempt to categorize the lymphomatous effusions according to the WHO classification, using archival material. METHODS: May-Grünwald-Giemsa and Papanicolaou-stained smears of 31 lymphomatous effusion specimens were reviewed. Of these, detailed cytological assessment was done on 12 pleural effusions and ten ascitic fluid specimens from 22 patients using the WHO lymphoma classification system. Immunocytochemical studies were performed in 21 specimens. RESULTS: Based on cytomorphological features, the 22 lymphomatous effusion specimens were categorized into lymphoplasmacytoid lymphoma (1), follicle centre cell (FCC) grade-1 (centrocytic) lymphoma (3), FCC grade-2 (centrocytic-centroblastic) lymphoma (3), FCC grade-3 (centroblastic) lymphoma (4), large cell immunoblastic lymphoma (4), lymphoblastic lymphoma (2), anaplastic large cell lymphoma (3) and miscellaneous types (2). Immunocytochemically, the lymphoma cells were T-cell (positive for CD3) and B-cell type (CD20 positive) in five and six cases respectively. CONCLUSION: Cytological examination of pleural effusion and ascitic fluid samples, supported by immunocytochemical studies, may be useful for the classification of lymphomas under the WHO system.     

FNAC of malignant lymphoma in an area with a high incidence of T-cell lymphoma. Correlation of accuracy of cytologic diagnosis with histologic subtype and immunophenotype

OBJECTIVE: To analyze the usefulness of fine needle aspiration cytology on malignant lymphoma in an area with a high incidence of T-cell lymphoma and to correlate the accuracy of cytologic diagnosis with histologic subtype and immunophenotype. STUDY DESIGN: We retrospectively studied the usefulness of fine needle aspiration cytology in the diagnosis of 49 cases of nodal and extranodal non-Hodgkin's lymphoma (NHL) and seven cases of Hodgkin's disease in a total of 56 patients in whom subsequent excisional biopsy revealed lymphoid malignancy. Slides showing the results of cytologic investigation were reviewed together with the information on which histologic diagnosis was based. On the basis of pathologic variables, such as prognostic groups based on the Working Formulation, so-called grade, cell size based on the modified Rappaport classification, and--in cases of NHL--immunophenotype, the accuracy of original and reviewed cytologic diagnoses was compared. RESULTS: Of the 49 cases of NHL, 8 (16.3%) were inadequate for cytologic diagnosis, and malignant lymphoma was diagnosed or suspected in 36 (73.5%), excluding inadequate specimens; the diagnostic accuracy for NHL was 87.8%. In high grade cases, malignant lymphoma was more easily diagnosed or suspected than in those that were low or intermediate grade. The rate of inadequate cases was highest in the "mixed small and large cell" category, and cases that were "false negative" were either composed entirely of small cells or contained a small cell component. Cytologic diagnosis or suspicion of malignant lymphoma was easily obtained in the "large cell" category, followed by mixed small and large cell and "small cell." Aspirates from non-B-cell type were more frequently acellular than those of B-cell type; with regard to diagnostic accuracy, however, there was no noticeable difference between the two immunophenotypes. CONCLUSION: In many cases in the mixed small and large cell category or where the immunophenotype was non-B, the aspirate was inadequate, and no definitive diagnosis was possible. Many of our cases of T-cell lymphoma were mixed small and large cell, and in Korea, where the incidence of extranodal and T-cell lymphoma is high, the usefulness of FNAC for the initial diagnosis of malignant lymphoma is limited. For a definitive diagnosis, biopsy is required.     

Nodal presentation of nasal-type NK/T-cell lymphoma. Report of two cases with fine needle aspiration cytology findings

BACKGROUND: Epstein-Barr virus (EBV)-associated NK/T-cell lymphoma typically occurs in extranodal sites, such as nasal cavity, nasopharynx, gastrointestinal tract, skin, testis and salivary gland. Secondary lymph node involvement is rarely encountered until late in the disease course. The fine needle aspiration cytology of NK/T-cell lymphoma with a nodal presentation has not been described before. CASES: Two cases of nasal-type (extranasal) NK/T-cell lymphoma with a nodal presentation were seen at Pamela Youde Nethersole Eastern Hospital, Hong Kong. Both patients presented with submandibular lymph node enlargement but unremarkable peripheral blood and bone marrow findings. Fine needle aspiration cytology was available in both cases, showing a heterogeneous population of small to medium-sized lymphoid cells, follicular center cells, plasma cells, eosinophils and some histiocytes. The medium-sized lymphoid cells showed readily discernible nuclear atypia with an irregular nuclear outline. Cell block sections revealed occasional lymphoid cells with pleomorphic nuclei. Immunocytochemical study confirmed the presence of CD56-positive lymphoma cells. In situ hybridization for EBV-encoded RNA also revealed positive nuclear signals. Histologic examination of the surgical biopsies showed interfollicular expansion by malignant lymphoid cells. Immunoglobulin heavy chain gene and T-cell receptor gene rearrangement studies demonstrated a germline pattern, confirming the putative NK (natural killer cell), non-B and non-T lineage of the lymphoma cells. CONCLUSION: Nodal presentation of NK/T-cell lymphoma, though rare, is diagnosable on the basis of fine needle aspiration biopsy alone, especially in view of its distinctive immunophenotype and EBV association. Recognition of the subtle but definite cytologic atypia of malignant lymphoid cells and presence of an appropriate background (including more eosinophils than usual), together with proper application of ancillary techniques, is crucial to arriving at a correct diagnosis.     

CD-30(Ki-1)-positive anaplastic large cell lymphoma in a pleural effusion. A case report with diagnosis by cytomorphologic and immunocytochemical studies.

BACKGROUND: Reports on cytodiagnosis of Ki-1-positive anaplastic large cell lymphoma (ALCL) are rare. This report describes one such case diagnosed by cytologic examination of a pleural effusion and confirmed by immunocytochemistry. CASE: An 87-year-old male presented with breathlessness, fever and a cough. Computed tomographic scan of the thorax showed a small, right, pleura-based nodule with infiltration of the immediate surroundings in addition to a massive, right-sided pleural effusion. Cytologic examination of pleural fluid revealed a heterogeneous population of cells comprising small mature lymphocytes, and numerous medium and large atypical lymphoid cells having frequent nuclear irregularity. Occasional very large cells resembling Reed-Sternberg cells or multinucleated cells with a horseshoe or wreathlike arrangement of nuclei (doughnut cells) were also present. Cytomorphology was suggestive of Ki-1 anaplastic large cell lymphoma (ALCL). Immunocytochemistry revealed intense positivity for CD-30, positivity for LCA and EMA in a variable number of cells and a negative result for cytokeratin except for occasional cells. CONCLUSION: Cytologic examination of pleural fluid can serve as a useful tool for the initial diagnosis of Ki-1-positive ALCL.     

Fine needle aspiration of follicular variant of papillary thyroid carcinoma presenting with pleural effusion: a case report

BACKGROUND: Malignant pleural effusion in association with mesothelioma, bronchogenic carcinoma and breast carcinoma is common, although less frequently reported with other malignancies. We report a follicular variant of papillary thyroid carcinoma (FVPTC), diagnosed on fine needle aspiration cytology (FNAC) of thyroid and lymph nodes and subsequently proved to have metastasized to the pleural cavity. CASE: A 46-year-old man presented with history of breathlessness, thyroid swelling, pleural effusion and bilateral cervical lymphadenopathy. FNAC of the thyroid swelling and the lymph nodes showed features of FVPTC with cervical lymph node metastasis. Pleural fluid examination led to suspicion of pleural involvement by metastatic deposit, confirmed by subsequent pleural biopsy. CONCLUSION: Thyroid malignancies presenting with pleural effusion are rare. In this case, although pleural fluid cytology suggested involvement of pleura, a definitive diagnosis could be rendered only on pleural biopsy. An ancillary aid, such as immunocytochemistry, could have helped establish pleural involvement on routine pleural fluid cytology alone. This case emphasizes the possible existence of rare cases of FVPTC that may be associated with a dismal prognosis. In our case, initial diagnosis of FVPTC could be made only on correlating FNA features of thyroid aspirate with those of lymph node aspirate.     

Stereotactic biopsy and cytological diagnosis of solid and cystic intracranial lesions

Cytological smears from 115 consecutive cases of stereotactic biopsies of intracranial lesions were reviewed. Ninety-five lesions were solid and 20 cystic. Material from 90 solid and 13 cystic lesions was sent both for cytological and histological examination. In 66 of the solid lesions, the cytological diagnosis was confirmed by histology (five were benign lesions and 61 malignant tumours: 56 primary brain tumours, three metastases and two lymphomas). In 24 cases with discrepant cytology and histology, the histology was inconclusive or insufficient in 14 cases, while cytology established the diagnosis of astrocytoma grade II (seven cases), metastases (two cases), gliosis (one case) and benign (four cases). Necrosis of tumour type was observed cytologically in six patients representing glioblastoma (two cases), anaplastic astrocytoma (one case), lymphoma (one case) and normal brain (two cases) histologically. Three cases reported cytologically as benign were primary brain tumour (two cases) and gliosis (one case). One smear of a glioblastoma was insufficient for cytological diagnosis. Cystic lesions were cytologically benign in 17 cases and malignant in three cases. Histology from the cyst wall confirmed the malignant diagnosis in three cases and showed tumour in six more cases, a benign process (two cases), changes induced by radiotherapy for arteriovenous malformation (one case) and insufficient material (one case). In conclusion, cytology from solid brain lesion allows an accurate diagnosis and subtyping of tumours in a majority of cases, and can thus be used to choose type of therapy. In cystic brain tumours, however, examination of the cystic fluid, is often inconclusive and a biopsy from the cyst wall should be performed if there is clinical or radiological suspicion of tumour.     

Primary malignant lymphoma of the uterine corpus diagnosed by endometrial cytology. A case report

BACKGROUND: A relatively small number of cases of primary malignant lymphoma of the uterine corpus have been reported, and it is rare for cases to be preoperatively diagnosed by cytology. CASE: A 59-year-old female experienced abnormal uterine bleeding of two months' duration. Preoperative evaluation of endometrial cytology revealed malignant cells. These cells demonstrated a rather round or oval configuration, with a markedly increased nuclear/cytoplasmic ratio, and were isolated and scattered in an inflammatory background. The nuclei were round or oval, and macronucleoli were marked. The cytologic diagnosis was malignant lymphoma. Postoperative histologic evaluation verified the presence of a primary malignant lymphoma in the uterine corpus, with a B-cell phenotype. CONCLUSION: Preoperative endometrial cytology correctly demonstrated malignant lymphoma of the uterine corpus.     

CYFRA21-1、MMP-3及CEA 和细胞学联合检查对恶性胸腔积液的诊断价值分析

摘要 目的：探讨细胞角蛋白19片段（CYFRA21-1）、基质金属蛋白酶-3（MMP-3）及癌胚抗原（CEA） 和细胞学联合检查对恶性胸腔积液的诊断价值。方法：选择2020年1月至2023年1月我院接诊的100例胸腔积液患者进行研究,并根据病理结果分为实验组47例（病理检查结果恶性）,对照组53例（病理检查结果良性）,分析血清CYFRA21-1、MMP-3及CEA 和细胞学水平变化情况及其的诊断价值。结果：实验组患者血清血清CYFRA21-1、MMP-3及CEA水平显著高于对照组,差异显著（P＜0.05）;实验组患者CYFRA21-1、MMP-3及CEA 和细胞学阳性率均显著高于对照组,差异显著（P＜0.05）;CYFRA21-1诊断恶性胸腔积液的AUC为0.989,95%CI为0.977~1.000;MMP-3诊断恶性胸腔积液的AUC为0.979,95%CI为0.964~0.994;CEA 诊断恶性胸腔积液的AUC为0.982,95%CI为0.967~0.997;细胞学诊断恶性胸腔积液的AUC为0.823,95%CI为0.766~0.879,联合检测时AUC为0.995,95%CI为0.990~1.000,较单独检测曲线下面积比较显著差异;且特异度、准确度均较单独检测更高。结论：CYFRA21-1、MMP-3及CEA 和细胞学联合检查可有效提高诊断恶性胸腔积液的准确性,临床应用价值高。     

Molecular genetic analysis in the diagnosis of lymphoma in fine needle aspiration biopsies. II. Lymphomas versus nonlymphoid malignant tumors

The configurations of immunoglobulin genes and T-cell receptor beta chain genes were analyzed by Southern blotting in DNA derived from nonlymphoid malignant tumors and lymphomas. Gene rearrangements were not detected in any of the 35 cases of nonlymphoid malignant tumors. On the contrary, they were shown in all 14 cases of non-Hodgkin's lymphomas, 2 of 3 cases of Hodgkin's disease and 2 cases diagnosed as non-Hodgkin's lymphoma or angioimmunoblastic lymphadenopathy. The differentiation by light microscopy between lymphoma and nonlymphoid malignant tumors was a diagnostic problem in five cases; the molecular genetic analysis of DNA was contributory in all five diagnostically difficult aspirates. By gene rearrangement studies, the diagnosis of lymphoma was confirmed in two cases and nonlymphoid malignant tumors were accurately indicated in aspirates diagnosed finally as rhabdomyosarcoma (one case) and carcinoma (two cases).     

Cerebrospinal fluid infiltration in Hodgkin lymphoma: a case report

BACKGROUND: Central nervous system (CNS) involvement by Hodgkin lympboma is a rare event. Involvement of the cerebrospinal fluid (CSF) in such cases is even more uncommon. We report a case of Hodgkin lymphoma in which the patient developed infiltration of the CSF while on chemotherapy. CASE: A 45-year-old woman was diagnosed with Hodgkin lymphoma by fine needle aspiration and subsequent biopsy of the cervical lymph node. She complained of headache during the course of chemotherapy, for which CSF examination was undertaken. Cytocentrifuge sediment of the CSF revealed marked eosinophilic pleocytosis, accompanied by scattered monocytes, polymorpbs, lymphocytes, plasma cells and histiocytes. An occasional large mononudlear cell with a large, round nucleus and prominent irregular nucleolus with a moderate amount of basophilic cytoplasm conformning to the morphology of Hodgkin's cells was noted. Binucleated Reed-Sternberg cells were not seen. Following intratbecal methotrexate, a reduction in the cellular infiltrate was observed. CONCLUSION: CSF cytology is important for the diagnosis of CNS involvement by Hodgkin lymphoma and may be positive before lesions can be visualized by magnetic resonance imaging or computed tomograpby scans.     

Cytopathological spectrum of unusual malignant pleural effusions at a tertiary care centre in north India

BACKGROUND: Cytological examination of pleural fluid is one of the most informative laboratory procedures in the diagnosis of pleural effusions. Although tuberculosis is the commonest cause of pleural effusions in developing countries, tumours, including grade ones, can present with effusions. OBJECTIVE: The aim of the present study was to evaluate the uncommon causes of malignant pleural effusion. METHODS: A 2-year retrospective analysis of pleural fluid cytological specimens submitted to the Department of Cytopathology, PGIMER, Chandigarh between January 2003 and December 2004 was performed to retrieve unusual metastases. Out of a total of 898 samples reviewed, 710 were negative for malignancy and 24 cases were suspicious for malignancy. The remaining 164 cases were positive for malignancy, out of which 38 cases revealed malignancies other than adenocarcinoma. RESULTS: The 38 unusual malignancies metastasizing to the pleural cavity included 29 haematological malignancies (non-Hodgkin's lymphoma, acute lymphoid leukaemia, multiple myeloma and chronic myeloid leukaemia) and nine non-haematological malignancies (Ewing's sarcoma, neuroblastoma, Wilms' tumour, squamous cell carcinoma, small-cell carcinoma and malignant fibrous histiocytoma). CONCLUSION: Although metastatic adenocarcinoma was the commonest aetiology of malignant pleural effusions, a significant number of unusual causes of malignant pleural effusion were also encountered.