Most Common Site of Glucagonoma
Glucagonomas most commonly occur in the body and tail of the pancreas, making option D (Body and tail) the correct answer. 1, 2
Anatomical Distribution
The National Comprehensive Cancer Network guidelines specifically identify the tail of the pancreas as the most common site for glucagonomas, which is why distal pancreatectomy with splenectomy is the standard surgical approach for these tumors. 1
Supporting Evidence from Multiple Sources:
Research studies consistently confirm this distribution: Most glucagonomas are solid tumors that arise in the body or tail of the pancreas. 2
Case reports demonstrate tail predominance: A documented case of a 70-year-old patient had an alpha-cell tumor located specifically in the tail of the pancreas. 3
Contrast with ductal adenocarcinoma: This distribution pattern is distinctly different from ductal adenocarcinoma of the pancreas, where 80-90% occur in the head of the gland. 4, 1 This anatomical difference is clinically important for differential diagnosis.
Clinical Implications of Location
Surgical Approach Based on Location:
For tail location (most common): The National Comprehensive Cancer Network recommends distal pancreatectomy with splenectomy and resection of peripancreatic lymph nodes. 1
For head location (less common): When glucagonomas do occur in the pancreatic head, pancreatoduodenectomy (Whipple procedure) with peripancreatic lymph node resection is required. 1
Small peripheral tumors (<2 cm): Enucleation or local excision with peripancreatic lymph dissection may be considered. 1
Important Caveat:
One retrospective study of 12 patients found that 50% had tumors located in the head of the pancreas, which contradicts the general consensus. 5 However, this single study's findings are outweighed by multiple other sources and guideline recommendations that consistently identify the body and tail as the predominant location. 1, 3, 2
Key Clinical Pearls:
Splenectomy is mandatory for glucagonomas due to their typically malignant nature with regional lymph node involvement, unlike other pancreatic neuroendocrine tumors where spleen preservation may be attempted. 6
Perioperative anticoagulation should be considered due to the hypercoagulable state associated with glucagonoma syndrome and increased risk of thromboembolism. 1, 6