Most appropriate initial method of investigation for carcinoma head of pancreas:

-Sensitivity of the USG is max when - Dist. b/w probe and organ is min. PA OF PANCREAS PROBE LOCATION Tail of Pancreas Stomach Head & Uncinate Process Duodenum Investigation for carcinoma head of pancreas: If the tumour size is < 1 cm and localised to small ducts and acini the preferred investigation modality is endoscopic USG, trans gastric biopsy. EUS is preferred because the distance is less between the probe and pancreas endoscopically and field of view is higher. Though trans gastric biopsy is not mandatory. It can be performed for histological confirmation and also avoids spillage of tumour cells. Histological confirmation is desirable but not essential as there is intense desmoplastic reaction in Ca head of pancreas, hence biopsy not mandatory as it cannot rule out the malignancy.