Impact of standardised reporting in adrenocortical carcinoma: a single centre clinicopathological review

Abstract

Aims: Structured multi-centre efforts are needed if the prognosis of adrenocortical carcinoma (ACC) is to be improved. Data collection may be enhanced through standardised histopathological reporting using criteria such as the recently published Royal College of Pathologists (UK) Minimum Dataset (MDS). This study aimed to perform a clinicopathological review of the adult patients treated at our institution in the ten years preceding the MDS.

Methods: Case records were examined for all patients diagnosed with ACC between 1996 and 2006. Pathology was reviewed and compared to the RCPath(UK) MDS along with the original reports. A systematic evaluation of Ki-67 immunolabelling was also performed.

Results: Eleven patients with ACC were diagnosed and treated at our institution. Histopathological reporting according to the MDS identified more features of malignancy than in the original reports (p<0.02). The median number of microscopic criteria of malignancy was 7 (range 5-10), with ≥5 features occurring in all cases. The most commonly observed features of malignancy were diffuse architecture, <25% clear cells, confluent necrosis, abnormal mitoses and mitotic count ≥6 per 50 high power fields. Capsular invasion and ≥8 MDS criteria of malignancy were both associated with a worse outcome (each p<0.01). Median Ki-67 index was 19.0% (range 3.7-44.1%) and was not apparently related to survival.

Conclusions: Standardised criteria for histopathological reporting of ACC will improve the accuracy of data for cancer registration and may also assist in individual patient stratification. An elevated Ki-67 index is a feature of ACC although does not appear to predict individual patient survival.