Accurate diagnosis of malignant and benign pancreatic masses can be challenging.
This may potentially delay treatment for cancer and subjecting patients with benign disease to unnecessary surgery.
Endoscopic ultrasound fine needle aspirate of pancreatic masses remains inconclusive in a subset of patients.
Dr Asif Khalid and colleagues from Pittsburgh studied the role of endoscopic ultrasound fine needle aspirate molecular analysis in this context.
The team recruited 6 patients with benign pancreatic masses, and 15 with malignant pancreatic masses with inconclusive cytology and positive cytology.
All cases had definitive pathology.
|The mean fractional mutation rate differed between samples|
|American Journal of Gastroenterology|
The researchers microdissected representative cells from each endoscopic ultrasound fine needle aspirate sample.
The team subjected each sample to PCR for analysis of 16 microsatellite allele loss markers situated at 1p, 3p, 5q, 9p, 9q, 10q, 17p, 17q, 21q, and 22q.
Loss of heterozygosity analysis used fluorescent capillary electrophoresis for quantitative determination of allelic imbalance.
The team also performed k-ras-2 point mutation analysis.
Mean fractional mutation rate was calculated and compared for each group.
The researchers found that all malignant cases carried multiple mutations, regardless of positive cytology or suspicious cytology.
The team noted that 5 of the 6 benign cases carried no mutations.
However, 1 case of autoimmune pancreatitis and coexisting PanIN lesions exhibited a k-ras mutation.
The team observed that the mean fractional mutation rate for the malignant and benign samples was significantly different.
Dr Khalid's team concludes, “Broad panel microsatellite loss and k-ras point mutation analysis can be reliably performed on endoscopic ultrasound fine needle aspirate samples from pancreatic masses and improves the diagnostic accuracy.”
“Furthermore, it accurately differentiates between malignant and benign pancreatic masses.”