Abstract

Introduction: Fine needle aspiration cytology (FNAC) is a popular preoperative tool to plan treatment preoperatively. Therefore, validation of its reliability and usefulness is critical. Cyto-histological correlation (CHC) is a recommended quality indicator (QI) for cytopathology reporting. CHC is underutilised, though it identifies individual reporting deficit.
Aim: To evaluatereliability of non-gynaecological FNAC, using one-year data, from a rural tertiary care teaching hospital and CHC as QI.
Objective: To use the one-year retrospective CHC exercise, as a clinical audit to evaluate the usefulness of institutional cytology reporting.
Materials and methods: Retrieval of non-gynaecological FNAC and surgical pathology data for the same one-year period to find matching CHC pairs.
Results: A total of 181 non-gynaecological FNACs were done in the given time period. These were from ‘Lymph node enlargements’ (57), ‘Breast’ (39), ‘Thyroid’ (24) and ‘Salivary glands’ (12). The rest “Others” (23) were mostly soft tissue. 26 Aspirates were ‘inadequate for opinion’ and excluded during analysis.
FNACs were grouped into:

Inflammatory, including granulomatous lesions.
Neoplastic-benign/malignant.
Inadequate for opinion.

Histological correlation was possible for 45 cases (29%) (45/155). Concurrence rate for CHC was 62% (28/45) with 38% (17/45) non-concurrence. The nonconcurrence was 11% (17/155) of the total FNAC workload. These were: 29% (5/17)- ‘change in categoric interpretation’, 35% (6/17)- ‘change within the same category’, 6% (1/17) due to lack of clinical information and 29% (5/17)due to preanalytical causes of error.All non-concurrences were congruent with known limitations of FNAC leading to sampling errors and hence posed methodological queries.
 
Conclusions:

The inherent limitations of the FNAC procedure may lead to non-concurrences in CHC.
When hierarchical reporting is the standard protocol in an institute, this incurs a blinding artefact to the deficits of individual reporting.
CHC exercise done at regular time intervals can serve as an internal clinical audit.