Comparison of diagnostic reliability of abdominal masses by ultrasound guided fine needle aspiration cytology (FNAC) with histology

Abstract

Objective: To determine the diagnostic reliability of FNAC (Fine Needle Aspiration Cytology) of abdominal masses. Design: Cross-sectional analytical (comparative study). Place and Duration of Study: Department of histopathology, Sheikh Zayed Hospital Lahore, Study period – 1 year. Materials and Methods: A total of 36 abdominal masses were subjected to FNAC from January 1999 to December 1999. Adequate aspirates were obtained in all cases, and consisted of 19 lymph nodes, including 13 unspecified abdominal lymph nodes, 3 retroperitoneal and 3 para-aortic nodes. Seventeen cases were from abdominal masses of unknown source, of which 5 were retroperitoneal masses, 6 right iliac fossa (RIF) masses and 6 epigastric masses. The smears were stained with haematoxylin and Eosin (H&E), Papanicolaou staining (PAP) and May-Grunwald Giemsa stains (MGG). Results of FNAC were categorized as benign (group I) malignant (group II) and non-neoplastic/inflammatory (group III). Excision biopsies from the same 36 cases were also obtained, processed and stained with routine H and E staining. Histology was taken as the gold standard. Results: On histological examination, 24 of the total 36 cases were categorized as malignant, 6 as benign, and 6 as non-neoplastic lesions. FNAC picked up all the 24 cases as malignant. In the benign group, 1 false negative was given, but there was no false positive diagnosis. The most common malignancy was diffused non-Hodgkin`s lymphoma, while benign fibrohistiocytic tumour, was the commonest benign tumour. Malignant and non-neoplastic lesions, revealed a 100% sensitivity and diagnostic accuracy, while benign tumours showed an 83.3% sensitivity and 91.6% diagnostic accuracy. Conclusion: Majority of the malignant tumours can be categorized on FNAC, with a high degree of accuracy, while benign tumours should be subjected to biopsy or excision, as there is a possibility of false negative diagnosis