Combined use of EUS-guided FNA and immunocytochemical stains discloses metastatic and unusual diseases in the evaluation of mediastinal lymphadenopathy of unknown etiology

Abstract

PURPOSE:Mediastinal lymphadenopathy (ML) is a cause for concern, especially in patients with previous malignancy. We report our experience with the use of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) with immunocytochemical stains in patients being evaluated for ML.METHODS:Retrospective analysis of patients with ML of unknown origin who underwent EUS-FNA. On-site evaluation was performed by experienced cytologist, and special immunocytochemical stains were requested as indicated.RESULTS:A total of 116 patients were included, and a total of 136 mediastinal LN were sampled. Prior malignancy was present in 45%. The most common site of examined lymph node (LN) were subcarinal (76%, 103 LN). The median long and short axis diameters were 28 mm and 13 mm, respectively. FNA was read on-site as malignant, 21 (16%); benign, 100 (76.9%); suspicious, six (4%); atypical, 3 (2%); and inadequate sample, six (4%). Sixty-four LN were deferred for additional studies; 22 for immunocytochemical and 26 for Gimesa (GMS) stain and 21 for flow cytometry. Final FNA read was malignant in 28 (21%), benign in 103 (76%), suspicious in three (2%), and atypical in two (1%). Metastatic malignancies disclosed included Hodgkin's and Non-Hodgkin's lymphoma, melanoma, hepatoma, breast, lung, colon, renal, endometrial, Fallopian tube, and unknown carcinoma. The sensitivity, specificity, and accuracy of the final FNA read to predict malignancy were 100%.CONCLUSION:EUS-guided FNA with additional ancillary studies is useful in disclosing metastatic ML from a variety of neoplasms. Due to its safety and accuracy profile, it should be considered the test of choice in evaluating abnormal ML in appropriately selected patients.

Is Liquid-Based Cytology the Magic Bullet for Performing Molecular Techniques?

“…In this domain, neoplastic lesions of lymph nodes, soft tissue sarcomas, gastrointestinal stromal tumors and colon cancers have been studied, and some results have shown the use of cytological material for the management of patients with these malignancies [58,59,60,61,62,63]. …”

Use of Ancillary Techniques in Improving the Yield of Samples Obtained at Endoscopic Ultrasound-Guided Fine Needle Aspiration of Thoracic and Abdominal Lymph Nodes

“…In the majority of cases, these lymph nodes are involved in lymphoproliferative processes, secondary spread of neoplasms or nonneoplastic processes [1,2]. Secondary tumors arising in the lung, the gastrointestinal tract, breast, the female genital tract and the pancreaticobiliary system commonly involve nodes in these areas.…”

“…Secondly, there is always a risk of false-positive diagnoses [2]. A tissue diagnosis is always needed in order to define the tumor type and to distinguish between neoplastic and nonneoplastic conditions [2]. Because of their location, tissue sampling from thoraco-abdominal lymph nodes has been difficult and has usually involved image guidance, traditionally by CT or ultrasound.…”

“…Secondly, there is always a risk of false-positive diagnoses [2]. A tissue diagnosis is always needed in order to define the tumor type and to distinguish between neoplastic and nonneoplastic conditions [2].…”

“…Secondary tumors arising in the lung, the gastrointestinal tract, breast, the female genital tract and the pancreaticobiliary system commonly involve nodes in these areas. A number of nonneoplastic conditions, such as tuberculosis and sarcoidosis, can also present with lymphadenopathy in these locations [2]. …”