Anterior mediastinal masses: A study of 50 cases by fine needle aspiration cytology and core needle biopsy as a diagnostic procedure

Abstract

Background: Mediastinal tumors are an uncommon abnormalities found in clinical practice. Anterior mediastinum is the common site and tissue diagnoses of anterior mediastinal masses (AMMs) are very important for correct therapeutic decision.

Objective: We evaluate the different malignant AMMs in various age groups and the sensitivity of fine needle aspiration cytology (FNAC) and core needle biopsy (CNB). Cytology smears are reviewed with particular emphasis on pitfalls in the cytological diagnosis.

Materials and methods: This was a prospective study of 50 patients who were consulted for AMMs and underwent FNAC and CNB under guidance of ultrasound or computed tomography (CT) scan from 2006 to 2011. Cytology smears and histological sections were evaluated in all patients.

Results: Among 50 cases, 36 were male and 14 were female. Most AMMs (52%) were identified in the fifth and sixth decades of life. Metastatic carcinoma and nonHodgkin's lymphoma are the common AMMs. Adequate tissue material was obtained in 49 of 50 cases by CNB. Of these 49 patients, 35 (71.42%) cases were diagnosed correctly by FNAC, whereas 14 (28.57%) cases were not diagnosed definitely by FNAC. The sensitivity of CNB for AMMs was 97.95%, significantly higher than FNAC (71.42%) (P < 0.05). CNB had statistically significant higher diagnostic rate than FNAC in the noncarcinoma group (100% versus 62.96%) (P < 0.05). There is no significant difference of CNB and FNAC in carcinoma group (P > 0.05). Diagnostic rate of FNAC was higher for carcinomatous lesions (81.81%) than for noncarcinomatous lesions (62.96%).

Conclusion: Ultrasound or CT scan-guided CNB in combination with FNAC are safe, minimally invasive, and cost-effective procedure, which can provide a precise diagnosis in the AMMs, and may obviate the need for invasive surgical approach. FNAC usually suffice for carcinomatous lesions but CNB should be performed whenever the diagnosis of carcinoma is equivocal or noncarcinoma lesions are suspected.

Keywords: Anterior mediastinal masses; core needle biopsy; fine needle aspiration cytology.

Figure 1

(a-c) Cytology smear shows binucleated Reed–Sternberg cells and mononuclear Hodgkin cells in the background of lymphocytes, eosinophils, plasma cells, and histiocytes (Hematoxylin–eosin stain, ×40); (d) Histological section shows mixed cellularity Hodgkin's lymphoma. Several Reed–Sternberg cells are seen with a polymorphic population of lymphocytes, eosinophils, plasma cells, and histiocytes (Hematoxylin–eosin stain, ×40)