Abstract
The unique radiological manifestation mimicking autoimmune pancreatitis caused by lung cancer metastasis to the pancreas has not previously been reported. The incidence of pancreatic secondary tumors has previously been reported to be approximately 15% in autopsy cases of malignant tumors, and it is unusual for thoracic oncologists to find that the second common primary tumor site of metastatic pancreas tumor is the lung.
Keywords: autoimmune pancreatitis, lung cancer, metastasis to pancreas
A 76‐year‐old woman presented to our emergency room with severe epigastric pain with muscular guarding. An abdominal computed‐tomography (CT) scan revealed diffuse swelling of the pancreas with panniculitis in the surrounding adipose tissue, and her serum amylase level was elevated to 755 U/l (Figure 1(a)). Although the sausage‐like appearance of the pancreas evoked autoimmune pancreatitis, 1 standard medical treatment for acute pancreatitis was initiated. Four days later, magnetic resonance imaging (MRI) scan for further examination was performed. Diffusion weighted MRI revealed multiple nodular lesions in her swollen pancreas (Figure 1(b)). Although she did not reveal her medical history with contrariness, her family declared that she had been diagnosed with primary lung cancer at another hospital five months previously. Therefore, with her permission, we obtained the results of the radiological examination.
FIGURE 1.
(a) Abdominal computed‐tomography revealed diffuse swelling of the pancreas with panniculitis in the surrounding adipose tissue. (b) Diffusion weighted magnetic resonance imaging (MRI) revealed multiple nodular lesions in her swollen pancreas
Fluorodeoxyglucose (FDG) positron emission tomography (PET)‐CT at initial diagnosis showed high uptake of FDG in the primary site of the right upper lobe. Although FDG high uptake was also observed in the lymph nodes in the mediastinum and supraclavicular fossa, there was no abnormal findings in the pancreas (Figure 2). We determined that her pancreatitis was caused by diffuse metastasis to the pancreas.
FIGURE 2.
Although high uptake of fluorodeoxyglucose (FDG) was observed in the primary site of the right upper lobe, lymph nodes in the mediastinum, and supraclavicular fossa, there was no abnormal findings in the pancreas
The incidence of cancer metastasis to the pancreas has previously been reported to be 15% in autopsy cases of all malignant tumors. The most common primary tumor site was the stomach, followed by the lung and extra hepatic bile duct. 2 However, to the best of our knowledge, a manifestation mimicking autoimmune pancreatitis has not previously been reported. Physicians should therefore be aware of the unique clinical course because lung cancer is the most frequent malignancy worldwide and the second main cause of metastatic pancreatic tumor.
CONFLICT OF INTEREST
All authors have no conflict of interest.
Ichiyama N, Yamane H, Ochi N, et al. Lung cancer metastasis to the pancreas mimicking autoimmune pancreatitis. Thorac Cancer. 2021;12:1467–1468. 10.1111/1759-7714.13951
REFERENCES
- 1. Kamisawa T, Egawa N, Nakajima H, Tsuruta K, Okamoto A, Kamata N, et al. Comparison of radiological and histological findings in autoimmune pancreatitis. Hepatogastroenterology. 2006;53:953–6. [PubMed] [Google Scholar]
- 2. Nakamura E, Shimizu M, Itoh T, Manabe T. Secondary tumors of the pancreas: clinicopathological study of 103 autopsy cases of Japanese patients. Pathol Int. 2001;51:686–90. [DOI] [PubMed] [Google Scholar]