A 47-year-old Chinese man was admitted at night to a local primary hospital for the first time because of persistent severe epigastric abdominal pain without radiating or referred pain. The symptom appeared unexpectedly without fever, jaundice, nausea, or vomiting and spontaneously resolved four hours later. The patient had previously been in good health. No laboratory tests, imaging studies, or therapy was performed the night the patient presented. The following day, abdominal computed tomographic scan was performed, the results of which revealed multiple enlarged lymph nodes in the retroperitoneal area and a suspected tumor mass in the pancreatic head region (Figure 1). Chest radiography revealed changes consistent of bronchitis. No laboratory tests were performed. The symptoms resolved spontaneously and did not recur. The patient was referred to a cancer hospital and presented approximately two weeks later for further evaluation of the suspected pancreatic neoplasm. The patient underwent exploratory laparotomy and retroperitoneal lymph node biopsy in the cancer hospital. The postoperative pathologic tissue diagnosis was reported as granulomatous lesions with no signs of malignancy. Subsequently, the patient was admitted to the outpatient department of our hospital for suspected gastrointestinal sarcoidosis. Laboratory testing revealed that the purified protein derivative (PPD) skin test result was negative, serum angiotensin-converting enzyme (ACE) level was 61.51 U/L (normal range, 23-43 U/L), and the level of immunoglobulin G antibody was normal. The anti-double-stranded DNA antibody, antinuclear antibody, and antineutrophil cytoplasmic antibodies were all negative. CT of the chest showed mediastinal lymphadenopathy. On the preliminary tests, the patient was initially diagnosed with retroperitoneal and mediastinal lymphadenopathy likely secondary to sarcoidosis. Finally, the patient was admitted to the pulmonary department of our hospital for the definitive diagnosis. The physical examination on admission was un-remarkable. Laboratory tests revealed that blood count, liver function, and renal function were all within normal limits. Tumor markers were within the normal range. ACE level was 117.37 U/L, significantly higher than the levels obtained in the outpatient setting. The repeat chest CT showed mediastinal and hilar lymphadenopathy and multiple bilateral pulmonary lesions (Figure 2). The abdominal ultrasonography revealed hypoechoic nodules in the pancreatic head region. The pathologic slices of retroperitoneal lymph node were sent to the pathology department of the hospital as well as to a specialty tuberculosis hospital for consultation. Results showed a granulomatous lesion. Further, acid-fast bacilli test results were negative, and both these results were supportive of the diagnosis of sarcoidosis (Figure 3). Because of these studies, therapy with prednisone (40 mg per day) was started. After five months on corticosteroid therapy, imaging studies showed dramatic improvement and complete regression of all lesions. On the basis of clinical presentation, chest and abdominal CT imaging results, response to steroids, and retroperitoneal lymph node pathology report, systemic sarcoidosis was diagnosed. Corticosteroid therapy was tapered and eventually discontinued over two years. The patient has not experienced any recurrence of sarcoidosis in the subsequent three years of follow-up.