Pancreatic acinar cell carcinoma with extension into the main pancreatic duct: a case report

Pancreatic mixed acinar-neuroendocrine carcinoma with intraductal growth: A case report with radiologic-pathologic correlations

Pancreatic mixed acinar-neuroendocrine carcinomas are rare malignant tumors of the pancreas. They are composed histologically of both acinar and neuroendocrine cells. The pancreatic duct is known to be an important site of tumor growth for acinar cell carcinomas, neuroendocrine tumors, and intraductal tubulopapillary neoplasms. To the best of our knowledge, there has been only 1 report of a mixed acinar-neuroendocrine carcinoma growing into the pancreatic duct and no reports detailing imaging findings with this tumor. We here report a 69-year-old man who presented with worsening glycemic control. Multiphase contrast-enhanced computed tomography and magnetic resonance imaging revealed a well-circumscribed mass with poor contrast enhancement in the pancreatic tail region of the pancreatic duct. The intraductal mass showed diffusion restriction on magnetic resonance imaging. These imaging findings are consistent with the expansive, smooth-surfaced polypoid tumor of low vascularity and high cellularity that was diagnosed pathologically. Mixed acinar-neuroendocrine carcinomas should be included in the differential diagnosis of intraductal tumors of the pancreas with poor contrast enhancement and diffusion restriction.

Curative remnant total pancreatectomy for recurrent pancreatic acinar cell carcinoma: A case report

Introduction and importance

Acinar cell carcinoma (ACC) of the pancreas is a rare pancreatic cancer subtype (incidence, 0.5–2%) with unclear epidemiology and prognosis. Sometimes, repeat resection including total pancreatectomy is required for recurrence. We report a case of ACC recurring in the remnant pancreatic head after distal pancreatectomy that was successfully cured by remnant pancreatic resection following combination therapy with nab-paclitaxel (nab-PTX) and gemcitabine (GEM).

Case presentation

A 64-year-old woman was referred for pancreatic tumour treatment. CT revealed a 46-mm tumour in the pancreatic body, and endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) indicated ACC. Distal pancreatectomy was performed, and the final diagnosis was ACC. CT 18 months later showed a 34-mm tumour in the remnant pancreatic head revealed as ACC by EUS-FNA. Portal vein invasion was apparent, so neoadjuvant chemotherapy with nab-PTX and GEM was administered, and remnant pancreatic resection (total pancreatectomy) was performed. No recurrence or distant metastasis was present more than 6 months later.

Clinical discussion

Mean survival time for ACC is 18–47 months, and prognosis is good compared with pancreatic ductal adenocarcinoma (PDAC). ACC tends to extend and grow along the main pancreatic duct, which increases the recurrence rate to 50–60%. EUS and EUS-FNA were useful for evaluating tumour extension and diagnosis. Repeat pancreatic resection that included total pancreatectomy was feasible and could be performed safely.

Conclusion

ACC has a better prognosis than PDAC but with a higher recurrence rate. Aggressive surgical resection that included remnant total pancreatotomy with chemotherapy was useful in treating ACC.

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Acinar cell carcinoma (ACC) of the pancreas is a rare type of pancreatic tumour.

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ACC has good prognosis compared with pancreatic ductal adenocarcinoma, but the recurrence rate is high.

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Surgical resection that includes remnant pancreatic resection is useful for pancreatic tumours.

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Neoadjuvant and adjuvant chemotherapy are useful in treating ACC.

Pancreatic acinar cell carcinoma with predominant extension into the main pancreatic duct: A case report

A 34‐year‐old male was referred to our hospital for a possible pancreatic mass detected by computed tomography (CT) that was performed to find the cause of acute pancreatitis. Multiple imaging tests, including contrast‐enhanced CT scan, magnetic resonance imaging, contrast‐enhanced endoscopic ultrasonography, and endoscopic retrograde pancreatography, revealed a solid mass occupying the head of the main pancreatic duct (MDP), and pancreaticoduodenectomy was performed. In the resected specimen, the tumor showed expansive growth from the pancreatic parenchyma to the MDP and formed a tumor plug. Histopathological findings together with immunostaining findings led to the diagnosis of pancreatic acinar cell carcinoma (PACC). The patient was alive and recurrence‐free for 11 years after surgery. Extension into the MDP is more common in PACC than in conventional pancreatic ductal adenocarcinoma. PACC patients with MDP extension may have less aggressive clinicopathologic characteristics, and a relatively good prognosis can be expected.

Transabdominal ultrasonographic diagnosis of relatively rare pancreatic neoplasms

There are various types of pancreatic neoplasms, and their prognosis and treatment methods are different. Therefore, accurate diagnosis is important to determine the best treatment strategy. Transabdominal ultrasonography is frequently used as a screening examination for diagnostic imaging of pancreatic neoplasms. In this review, we have focused on the characteristics of ultrasonic findings for relatively rare pancreatic neoplasms.