Acinar cell carcinoma of the pancreas presenting as diffuse pancreatic enlargement

Abstract

Rationale:Pancreatic acinar cell carcinoma (ACC) is a rare malignant tumor of exocrine pancreas. It is typically a well-marginated large solid mass arising in a certain aspect of the pancreas. Diffuse involvement of ACC in the pancreas is very rare, and may simulate pancreatitis in radiological findings. We report 2 cases of ACC presenting as diffuse enlargement of the pancreas due to tumor involvement without formation of a distinct mass.Patient concerns:The patients consisted of a 41-year-old man with weight loss and a 77-year-old man who was asymptomatic.Diagnoses:Computed tomography (CT) and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT showed diffuse enlargement of the pancreas forming a sausage-like shape with homogenously increased FDG activity.Interventions:Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) biopsy of the pancreatic lesion was performed.Outcomes:Histopathology results from the pancreas confirmed the diagnosis of pancreatic ACC.Lessons:Because diffuse enlargement of the pancreas is a common imaging feature of pancreatitis, recognition of this rare morphologic pattern of ACC is important for radiological diagnosis of this tumor.

Pancreatic acinar cell carcinoma with pleomorphic and spindle cells: An autopsy‐proven case

“…Our case, on the other hand, showed slight swelling of the pancreatic head, rather than a mass. In the literature, pancreatic acinar cell carcinoma is reported to occasionally show atypical features such as diffuse enlargement of the pancreas like a sausage 9,10 . In the study by La Rosa et al, tumor infiltration of the whole pancreas was seen in only one of 62 cases 5 .…”

Computed tomography features of acinar cell carcinoma of the pancreas

“…Researchers have reported unusual imaging features of pancreatic ACC [9,21]. Luo et al have reported two ACCs presenting as diffuse enlargement of the pancreatic gland displaying a "sausage-like" shape [21]. Hashimito et al have reported similar feature in one patient [20].…”

“…The CT features of pancreatic ACC have been described in several studies and some suggestive features have been identified [10,[12][13][14][15][16][17][18]. However, ACC of the pancreas may sometimes display nonspecific or misleading features on CT [9,14,19,20,21]. In addition, the capabilities of CT in discriminating between pancreatic ACC and PDA have not been elucidated yet because in the single study that made such comparison, only six patients with pancreatic ACC were included and the comparison was restricted to tumor enhancement patterns [22].…”

Rapid Response to the Combination of Lenvatinib and Sintilimab in a Pancreatic Acinar Cell Carcinoma Patient With Elevated Alpha-Fetoprotein: A Case Report

“…It can originate from the pancreas, salivary gland, prostate, and lung ( 2 ), among which pancreatic acinar cell carcinoma (PACC) is the most common. PACC, which was first reported in 1908, accounts for 1%–2% of all pancreatic tumors and mainly occurs in the pancreas head of medium-elderly men ( 3 , 4 ). However, alpha-fetoprotein (AFP)-elevated PACC is rare with no more than 30 cases being reported worldwide ( 5 , 6 ).…”