Flow cytometric immunophenotyping in fine-needle aspiration of lymph nodes.

Fine-needle aspiration (FNA) of lymph nodes has been regarded as a useful method in the diagnosis of lymphadenopathy. However, this procedure has been shown to be of limited value in the diagnosis of low or intermediate grade malignant lymphomas in some studies. Immunophenotyping is an essential adjunct to cytomorphology for the diagnosis of lymphoma by FNA. Immunophenotyping using flow cytometry (FCM) is rapid, objective and reliable. Using FCM, multiparametric analysis of 33 FNA materials from lymph nodes was performed and profiles of surface markers of lymphoid cells were assessed. In reactive hyperplasia, patterns of cell surface markers were quite variable, but disclosed polyclonality. Most of the B-cell lymphomas showed immunophenotypes for B-cell lineages with their kappa: lambda or lambda: kappa ratio being over 3:1. In T-cell lymphomas, T-cell surface markers were predominantly expressed as well. In conclusion, our results suggest that immunophenotyping of lymph node aspirates is a valuable diagnostic adjunct for lymphoproliferative disorders, particularly in B-cell lymphomas because immunophenotyping can be easily and adequately performed by FCM.     

Wide needle aspiration cytology in the diagnosis of lymphadenopathy in Zambia.

AIMS--To study the value of wide needle (19 gauge) aspiration cytology in the diagnosis of lymph node disease in Zambia in the absence of a trained cytologist. METHODS--Patients (n = 304) referred for surgical biopsy of an enlarged peripheral lymph node were studied prospectively. Surgical biopsy was routinely preceded by 19 gauge needle aspiration of the same node; aspirates were stained by haematoxylin and eosin and Ziehl Neelsen stains. RESULTS--Of 232 aspirates, 182 contained sufficient material for cytological characterisation. Tuberculosis was diagnosed or suspected in 122 of 126 aspirates with histologically confirmed tuberculous lymphadenitis; reactive follicular hyperplasia in 31 of 38 patients with primary HIV lymphadenopathy; malignancy in all five patients with malignant nodes; and Kaposi's disease in four of nine patients with this. Tuberculous lymphadenitis was falsely suspected in four patients, as was reactive follicular hyperplasia in four, and Kaposi's disease in four. CONCLUSIONS--Wide needle aspiration cytology is useful in the diagnosis of lymphadenopathy in Central Africa, with the exception of lymphadenopathic Kaposi's disease.     

Fine-needle aspiration diagnosis of Kaposi's sarcoma in a developing country

Fine-needle aspiration (FNA) cytology was performed on 15 patients with peripheral lymphadenopathy and/or skin lesions referred to the Department of Pathology of the Hospital Central of Maputo, Maputo, Mozambique. Epitrochlear lymph nodes were the most frequently aspirated site. All aspirates allowed diagnoses of Kaposi's sarcoma (KS). Smears contained loosely cohesive clusters of bland spindle cells, with a radial arrangement and nuclear crush artifacts. These diagnostic clues have not been described in other spindle-cell intranodal lesions that should be considered in differential diagnoses. Taking into consideration the high prevalence of AIDS and limited resources for diagnosis in Africa, FNA cytology appears to be a useful method for the diagnosis of KS in developing countries, reducing the necessity for surgical lymph node excision.     

Fine needle aspiration cytology diagnosis of malignant lymphoma and reactive lymphoid hyperplasia.

AIMS: To assess the diagnostic accuracy of lymph node fine needle aspiration (FNA) cytology to distinguish reactive lymphoid hyperplasia from malignant lymphoma, and to evaluate the contribution of ancillary techniques applied to cytological material. METHODS: Two hundred and seventy seven consecutive lymph node FNA specimens reported to be consistent with reactive lymphoid hyperplasia (n = 213) or suggestive/diagnostic of malignant lymphoma (n = 64) were reviewed. Follow up data were obtained by case record review or by histological correlation. The value of immunocytochemistry, in situ hybridisation for immunoglobulin light chain mRNA, and polymerase chain reaction (PCR) towards the final clinicopathological diagnosis was assessed in 92, 61, and 45 cases, respectively. RESULTS: Sixty one of 67 lymphomas and 207 of 209 reactive lymph nodes were accurately diagnosed by FNA cytology. There were six false negative aspirates including three cases of follicular lymphoma, two cases of Hodgkin's disease, and one chronic lymphocytic leukaemia. Two FNA specimens considered suspicious of lymphoma proved reactive on histology or clinical follow up. One metastatic small cell carcinoma was wrongly diagnosed as lymphoma. Ancillary studies contributed to the correct diagnosis in most cases although occasional misleading results were obtained, particularly with PCR. CONCLUSIONS: FNA cytology accurately distinguished reactive lymphoid hyperplasia from malignant lymphoma in 97% of cases. However, occasional wrong diagnoses occurred owing to sampling error or misinterpretation. Ancillary studies can be applied to cytological samples and contribute to the diagnosis in most cases.     

Fine-needle aspiration of histiocytic necrotizing lymphadenitis (Kikuchi's disease)

Fine-needle aspiration (FNA) of the lymph node was done in five patients with histiocytic necrotizing lymphadenitis (Kikuchi's disease). In four patients, the aspirates were found to have many small and large atypical lymphocytes, some reactive, phagocytic histiocytes, and intense extracellular debris. Neutrophils, plasma cells, or multinucleated giant cells were not seen. These cytologic findings were considered diagnostic for Kikuchi's disease. In one patient, the aspirate did not show significant histiocytosis or tissue necrosis and was considered nondiagnostic. In patients with both typical clinical features and characteristic cytologic findings in the lymph node aspirates, FNA of the lymph node alone will suffice for diagnosis. In those patients with typical clinical features but nondiagnostic findings in the FNA aspirates, the diagnosis of Kikuchi's disease may have to be established either on repeated nodal FNA or on lymph node biopsy.     

Diagnosis and subclassification of primary and recurrent lymphoma. The usefulness and limitations of combined fine-needle aspiration cytomorphology and flow cytometry

The primary diagnosis of non-Hodgkin lymphoma/leukemia by fine-needle aspiration (FNA) is still controversial and relatively underused. We evaluated our FNA experience with lymphomas using the revised European-American classification of lymphoid neoplasms to determine the reliability of FNA when combined with flow cytometry in the diagnosis of lymphoma, the types of diagnoses made, and the limitations of this technique. Slides and reports from all lymph node and extranodal FNAs performed during the period January 1, 1993, to December 31, 1998, with a diagnosis of lymphoma or benign lymphoid process were reviewed. There were 290 aspirates from 275 patients. These included 158 cases of lymphoma, of which 86 (54.4%) were primary and 72 (45.6%) were recurrent. There were 44 aspirates suggestive of lymphoma and 81 benign/reactive diagnoses. With diagnoses suggestive of lymphoma considered as positive for lymphoma, levels of diagnostic sensitivity and specificity were 95% and 85%, respectively. Specificity was 100% when only definitive diagnoses of lymphoma were considered. Clearly, FNA and immunophenotyping by flow cytometry are complementary and obviate a more invasive open biopsy for many patients with lymphadenopathy.     

Endoscopic ultrasound-guided fine-needle aspiration of lymph nodes: the Hennepin County Medical Center experience

Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) allows for the sampling and diagnosis of lesions of the gastrointestinal system and adjacent tissues. It has also proved helpful with the sampling of lymphadenopathy both for the staging of malignancy and for the diagnosis of lymphadenopathy of other causes. We review our experience with EUS-guided FNA of lymph nodes. The cytology files were searched at Hennepin County Medical Center (HCMC) for all cases of lymph nodes sampled by EUS. Clinical history, biopsy site, diagnosis, and follow-up information (including ancillary testing) were reviewed. Between January 1, 2000 and December 5, 2002, 217 lymph nodes from 185 different patients were sampled by EUS at HCMC. Biopsy sites included 62 mediastinal, 9 paraesophageal, and 146 intra-abdominal lymph nodes. Diagnoses were as follows: metastatic non-small cell carcinoma (n = 69); benign, reactive lymph node (n = 76); granulomatous lymphadenopathy (n = 18); malignant lymphoma (n = 7); atypical-suspicious for malignancy (n = 5); metastatic small cell carcinoma (n = 2); necrotic debris (n = 4), and foreign material (n = 1); 35 cases were nondiagnostic (16.1%) in 22 of 185 patients (11.9%). Ancillary tests including flow cytometry, cytogenetics, and cultures were performed. EUS-guided FNA of mediastinal and intra-abdominal lymph nodes provides diagnostic material from which ancillary testing may be performed.     

Nevus-cell aggregates in lymph nodes: fine-needle aspiration cytologic findings and resulting diagnostic difficulties

We report a case of nodal nevus present in enlarged lymph nodes with changes of dermatopathic lymphadenopathy sampled by fine-needle aspiration (FNA) cytology prior to clinical evaluation of the patient. This lymph node pathology was established later by lymph node excisional biopsy, by which along with a skin biopsy the dermatopathic lymphadenopathy was tentatively attributed to early mycosis fungoides. The FNA revealed fairly atypical melanotic tissue from the dermatopathic lymphadenopathy along with nodules of uniform melanocytic nevoid cells, the presence of which in combination with the dermatopathic atypical tissue provided a tentative diagnosis of metastatic melanoma of unknown primary, with the diagnosis of nodal nevus presented as a less likely possibility. This is to our knowledge the first cytologic report on FNA of nodal nevus, which besides presenting cytologic findings of this entity highlights some of the problems related to providing an accurate diagnosis, if this exceptionally unusual pathologic entity is encountered in lymph nodes sampled for enlargement from pathologies unrelated to this entity. The subject of nevus changes in lymph nodes is briefly discussed.     

Fine-needle aspiration cytology in the diagnosis of superficial lymphadenopathy: An analysis of 2,418 cases

During a period of 5 yr, 2,418 fine-needle aspirations (FNA) were performed on 2,216 patients with superficial lymphadenopathy. Chronic nonspecific lymphadenitis was the commonest inflammatory lesion followed by tuberculosis. Among malignant lesions, metastatic tumors were most common followed by non-Hodgkin's lymphoma. The FNAC findings were correlated with subsequent histopathological diagnosis in 1,041 cases. The sensitivity rates of FNAC in tuberculosis, metastatic tumors, Hodgkin's disease, and non-Hodgkin's lymphoma were found to be 83.3, 97, 30, and 80.3%, respectively, the specificity being 94.3, 98.9, 98.6, and 95.4% in the same order. Immunocytochemical tests performed on the aspirated material helped in classifying the metastatic poorly differentiated tumors and confirming the diagnosis of non-Hodgkin's lymphomas. Effects of FNA on subsequent biopsy in 81 lymph nodes with benign hyperplasia were studied and showed that aspiration does not interfere with subsequent histologic assessment. Thus FNAC is a simple, inexpensive procedure, and when complemented by appropriate immunocytochemical studies is accurate and reliable for routine diagnosis of lymphadenopathy. Diagn Cytopathol 1996;15:382–386. © 1996 Wiley-Liss, Inc.     

Use of fine needle aspiration cytology for investigating lymphadenopathy in HIV positive patients.

The cytological diagnoses of 27 lymph node aspirates were compared with the histological diagnoses or clinical outcome in 23 HIV positive patients. There was agreement between the cytological and histological diagnoses in 14 of the 16 surgically biopsied cases. The clinical outcome in the remaining 11 cases was consistent with the cytodiagnosis. Fine needle aspiration (FNA) is a reliable, minimally traumatic, cost effective method with high specificity. It is suitable for an initial rapid diagnosis in HIV positive patients with lymphadenopathy.     

Value and limitations of fine-needle aspiration cytology in diagnosis and classification of lymphomas: A review.

The fine needle aspiration (FNA) cytologic diagnosis of non-Hodgkin's lymphoma (NHL) depends upon finding a relatively monotonous population of lymphoid cells in smears. Lymphomas have successfully been classified by FNA cytology following the prevalent histologic classifications. The success rate of FNA cytology ranges from 80%-90% in diagnosis of NHL and from 67.5%-86% in its subtyping. The cytodiagnosis of Hodgkin's disease (HD) depends upon demonstration of Reed-Sternberg cells or Hodgkin's cells amongst appropriate reactive cell components. The diagnostic accuracy of FNA cytology for HD has also been invariably high (>85%). Yet, the role of cytology in primary diagnosis, subclassification and management of patients with lymphoma remains controversial. The differential diagnostic problems for NHL include a group of small round cell tumors, nonlymphoid acute leukemias and HD. Reservations have been expressed regarding the efficacy of cytology in separating florid reactive hyperplasia from low-grade malignant lymphoma. The reported cytodiagnostic accuracy for follicular lymphomas and nodular sclerosis type of HD is less compared to other subtypes of NHL and HD respectively since nodular pattern and sclerosis are strict histologic criteria which can not be appreciated in cytologic preparations. Entities like atypical lymphoproliferative disorders, peripheral T-cell lymphomas and Ki-1 positive anaplastic large cell lymphomas pose diagnostic challenges to cytologists. Despite these limitations, FNA cytology remains the first line of investigations (screening test) used in cases of lymphadenopathy. Besides initial diagnosis of lymphoma, it helps in detection of residual disease, recurrences and progression of low-grade to high-grade lymphoma, and helps in staging the disease. Availability of prior FNA cytology report facilitates the histologic diagnosis and classification of NHL. Various special ancillary techniques are now being performed on lymph node aspirates to diagnose lymphoma versus other malignancies, and to decide the functional character of lymphomas and their clonal nature. Diagn. Cytopathol. 1999;21:240-249.     

Cytomorphological patterns of M. bovis BCG and M. tuberculosis on fine needle aspiration biopsies: Does HIV make a difference?

To determine if fine needle aspiration (FNAB) of mycobacterial lymphadenopathy can differentiate infection with M. bovis BCG (BCG) from M. tuberculosis (TB) and whether HIV status affects discriminatory cytological features. A retrospective study of culture positive, fine needle aspiration biopsies of lymph nodes in children (<13 years) between 2003 and 2008. A total of 77 aspirates were available for evaluation with 67 (87%) patients having known HIV status. BCG occurred at a younger age (6 months), predominantly axillary lymph nodes (90%) compared with TB (5 years and 20% axillary lymph nodes). Amorphous necrosis was only seen in aspirates from TB lymph nodes, while in HIV negative children with TB, foamy macrophages were absent. On ZN staining there were more organisms in the BCG group and in HIV positive patients the organisms were present in both extra- and intracellular locations, whereas in the HIV negative patients the organisms were predominantly extracellular in location. Demographic and cytomorphologic features that can assist in distinguishing between the two mycobacterial species include: age of patient, location of the lymph node, and presence/absence of amorphous necrosis and foamy macrophages on FNAB. However the only reliable method to identify the mycobacterial species is by mycobacterial culture and/or PCR.     

Fine-needle aspiration of superficial and deeply seated lymph nodes on patients with and without a history of malignancy: review of 439 cases

This study addresses the utility of fine-needle aspiration (FNA) in assessing lymphadenopathy in patients with and without a previous history of malignancy. We reviewed the FNAs of superficial and deeply seated lymph nodes performed at our institution over a period of 18 yr (1983-2001). Where applicable, we also reviewed and report here the results of subsequent surgical excisional biopsies. We analyzed data from 439 patients, who ranged in age from 1 to 90 yr. The neck and retroperitoneum were the most frequently sampled sites (47% and 25%, respectively). Among the 439 FNAs, adequate material was obtained in 421 cases (96%); the remaining 18 were unsatisfactory (4.1%). Malignant diagnoses were rendered in 330 cases (75% of 439), four were suspicious for lymphoma (0.9%), and 87 were read as reactive lymph nodes or granulomas (20%). The most common malignant cytologic diagnoses from these lymph node FNAs were adenocarcinoma, squamous cell carcinoma, and lymphoma. We compared results between two major groups: patients with a history of malignancy and those without. FNA showed malignancy in 87% of patients with a history of cancer and 41% without such a history. Thirty-three or 10% of patients with a history of malignancy were given a benign diagnosis and follow-up surgical excisional biopsies were performed in nine of these cases. Four of the nine showed low-grade lymphoma. Of the 18 non-diagnostic FNAs, nine came from patients with a history of malignancy and in six of these nine who had a follow-up surgical excisional biopsy the lymph nodes were positive for malignancy. Of the other nine, who had no history of malignancy, only two had follow-up biopsies and both of these were negative. Patients with a history of malignancy are more than twice as likely to show malignancy on lymph node FNA compared to those without such a history (87% vs. 41%). Knowing whether a patient has a history of malignancy provides the appropriate level of suspicion for ordering ancillary investigations or even recommending excisional biopsy for further evaluation.     

Cystic change in metastatic lymph nodes: a common diagnostic pitfall in fine-needle aspiration cytology

Fine-needle aspiration cytology (FNAC) of cystic metastases is a challenging diagnostic category and has been investigated in a limited number of malignancies and sites. The present study retrospectively reviewed 1,211 FNAC of superficial masses, including lymph nodes (1,102 aspirates), benign cystic lesions (64 aspirates), and lymphocysts (45 aspirates) with the aim of determining the tumors that cause cystic change in metastases. Cytology results from 1,102 lymph node aspirations were suspicious or positive for malignancy in 541 specimens (49.1%), benign in 230 (20.9%), and unsatisfactory in 331 (30%). There were 28 malignant aspirates demonstrating cystic change (5.2%). The tumor type that most frequently caused cystic change was thyroid papillary carcinoma (42.8% of cases), followed by squamous cell carcinoma (primary in the head and neck region 30.8% and in the skin 24%), tumors of unknown origin (6.3%), serous papillary carcinoma of the ovary or endometrium (4.8%), and malignant melanoma (2.1%). Cystic change was observed most commonly in the head and neck region lymph nodes (60%). The most challenging lesions to assess using FNAC were metastatic lymph nodes showing cystic change, accounting for six of the 16 false-negative diagnoses and one false-positive diagnosis. The results of this study suggest that cystic change in metastatic lymph nodes occurs in certain types of tumors and is an important cause of diagnostic error. FNAC should be repeated in case of suspicious hypocellular cystic aspirations, especially in patients with known malignancy.     

Lymph node aspiration biopsy. Diagnostic reliability and limitations--an analysis of 350 cases

The results of fine needle aspiration biopsy of lymph nodes in 350 patients and the modified biopsy technique used at our institution are discussed. Of the 350 cases, 209 aspirates were categorized as cytologically malignant, 102 as benign, 30 as suspicious for malignancy, and 9 as unsatisfactory. Cervical lymph nodes were most commonly sampled (58%), and supra-clavicular nodes were most likely to be malignant (90%). The overall diagnostic accuracy achieved was 94%. One false-positive and 9 (2%) false-negative results were observed in the 350 cases. In 3% of the 30 cases diagnosed as suspicious for malignancy, follow-up open biopsy of the lymph nodes in question proved them benign. The advantages and limitations of the procedure are discussed, as well as some of the possible sources of error, particularly in the diagnosis of lymphomas.     

Role of fine-needle aspiration cytology in breast lymphoma

Lymphomas of the breast are rare and may mimic carcinoma clinically. We investigated the ability of fine-needle aspiration (FNA) biopsy combined with adjunctive flow cytometry (FC), immunofluorescence microscopy (IFM), and immunocytochemistry (ICH) to diagnose and eventually subclassify lymphomas of the breast according to the Revised European American Lymphoma/World Health Organization classification. We retrieved 21 breast aspirates from 19 patients with a cytologic diagnosis of lymphoma or plasmacytoma over a 10-year period (1992-2002), excluding 98 benign intramammary lymph nodes and 1 atypical lymphohistiocytic proliferation (Rosai Dorfman disease). FC was performed in 15/21 aspirates, IFM in 1/21, ICH in 3/21. Histologic follow-up (HF) was obtained for 10 patients, most of them with primary lymphoma. For the remaining nine patients without HF, flow cytometric analysis, comparative morphology, or remission after chemotherapy regimens supported the cytologic diagnosis. Of 19 patients, 11 patients had a secondary lymphoma (SL) and 8 patients had a primary lymphoma (PL). FNA and FC/IFM/ICH classified 7/8 PLs as B-cell lymphomas and 1/8 PLs as plasmacytoma. However, FNA could only subclassify 3 of 8 PLs. FNA and/or FC subclassified accurately 10/11 SLs. All cases were accurately immunophenotyped as B-, T-cell non-Hodgkin's lymphomas or plasmacytoma. World Health Organization classification was achieved in 3/8 PLs (42%) and 10/11 SLs (91%; P = 0.04). Subclassification (which has an impact on long-term management and prognosis) was significantly better in SL, when a previous histologic diagnosis had already been made, when compared to PL, of which 5/8 cases (62.5%) could not be accurately classified.     

Lymph node cytology in Wegener's granulomatosis

We report on cytological findings on aspirates from the cervical lymph node from a case of Wegener's granulomatosis (WG). The diagnostic utility of technique in diagnosing a sizable minority of WG patients who present with cervical lymphadenopathy is discussed. We outline an approach to diagnosis of necrotising granulomatous lesions in aspirates from lymph nodes in a tabular form.     

Histiocytic necrotizing lymphadenitis diagnosed by conventional cytology and liquid based cytology

Histiocytic necrotizing lymphadenitis (HNL; Kikuchi-Fujimoto disease) is a rare benign disorder. The diagnosis of HNL is established on recognizing the characteristic histologic findings from biopsy of the enlarged lymph nodes. Though diagnosis of HNL by fine-needle aspiration (FNA) was reported, the characteristic fine-needle aspiration cytologic features with conventional cytology and a liquid based cytology test (LCT) have not been well documented. In this study, 42 cases of suspicious necrotic lymph nodes were subjected to cytology and biopsy diagnosis. The lymph nodes were aspirated using a 10 mL disposable syringe with the percutaneous ultrasound guided. Samples were used for conventional cytology and LCT. Among 42 cases of suspicious necrotic lymph nodes, 37 of cases were histologically confirmed as HNL; 3 of cases were hyperplasia of lymphoid tissue; 1 case was tuberculosis of lymph node, and 1 case was classical Hodgkin lymphoma (nodular sclerosis type). 31 out of 37 (83.8%) cases of HNL were diagnosed by conventional cytology, 33 out of 37 (89.2%) were diagnosed by LCT. Our results indicate that no significant difference on accuracy rate between conventional cytology and LCT, but LCT has its advantages in the diagnosis of HNL.     

Diagnostic accuracy of fine needle aspiration cytology in providing a diagnosis of cervical lymphadenopathy among HIV-infected patients

BackgroundOpportunistic infections and malignancies cause lymphadenopathy in HIV-infected patients. The use and accuracy of fine needle aspiration cytology in diagnosing of cervical lymphadenopathy among HIV-infected patients is not well studied in Uganda.ObjectiveThe aim of this study was to determine the diagnostic accuracy of fine needle aspiration cytology in providing a diagnosis of cervical lymphadenopathy among HIV-infected patients in Uganda.MethodsWe consecutively recruited adult HIV-infected patients with cervical lymphadenopathy admitted to Mulago Hospital medical wards. Clinical examination, fine needle aspiration and lymph node biopsy were performed. We estimated the sensitivity, specificity; negative and positive predictive values using histology as the gold standard.ResultsWe enrolled 108 patients with a mean age of 33 years (range, 18–60), 59% were men and mean CD4 was 83(range, 22–375) cells/mm³. The major causes of cervical lymphadenopathy were: tuberculosis (69.4%), Kaposi''s sarcoma-KS (10.2%) and reactive adenitis (7.4%). Overall fine needle aspiration cytology accurately predicted the histological findings in 65 out of 73 cases (89%) and missed 7 cases (9.5%). With a sensitivity of 93.1%, specificity of 100%, positive predictive value of 100% and negative predictive value of 78.7% for tuberculosis and 80%; 98.4%;88.9% and 98.9% for KS respectively. No fine needle aspiration complications were noted.ConclusionsFine needle aspiration cytology is safe and accurate in the diagnosis of tuberculosis and KS cervical lymphadenopathy among HIV-positive patients.     

Immunocytochemical analysis of lymph node aspirates in patients with human immunodeficiency virus infection.

Thirty four patients positive for human immunodeficiency virus (HIV) who had lymphadenopathy were investigated using fine needle aspiration. Cytological analysis included immunocytochemical investigation with the alkaline phosphatase-antialkaline phosphatase (APAAP) method. All patients had confirmation of cytological diagnosis by lymph node biopsy. Fifteen aspirates with follicular hyperplasia were evaluated. Eleven patients showed B cell predominance. The B cell population did not show light chain restriction. Ten patients with B cell non-Hodgkin's lymphoma (five with Burkitt's lymphoma and five with B cell immunoblastic lymphoma) were investigated. Nine out of 10 cases were monoclonal with respect to their light chain determinants; only one case with Burkitt's lymphoma with partial lymph node metastasis did not show light chain restriction. The cytological diagnosis included two mycobacterial infections and four cystic lesions. Histological investigation was necessary to diagnose the extent of lymph node disease caused by Kaposi's sarcoma. These findings indicate that the immunocytological investigation of lymph node aspirates is useful for evaluating lymphadenopathy in HIV positive patients.