BACKGROUND Signet ring cell carcinoma (SRCC) is a specific type of mucinous secretory adenocarcinoma, which contains abundant mucus in the cytoplasm and pushes the nucleus to one side of the cell membrane, forming a round or oval, and the nuclear deviations give the cells a signet ring-like appearance. SRCC often originates in the gastrointestinal tract, especially in the stomach. However, primary SRCC of the extrahepatic bile duct is extremely rare. Therefore, little is known about its epidemiology, treatment, and prognosis. CASE SUMMARY An 82-year-old female was admitted with abdominal pain, jaundice, and skin pruritus for 2 mo. She had no specific family history. Physical examination presented normal vital signs, icteric sclera, visible jaundice, and mild tenderness in the right upper abdominal quadrant. Tumor-related cell markers were within normal values. Contrast-enhanced computed tomography revealed a thickened wall of the common bile duct, strengthened with intrahepatic bile duct dilation and multiple round-like lesions in the liver. In addition, the lymph nodes in the hepatic hilum area, the pancreatic head area, and around the abdominal aorta were enlarged. Thus, a preoperative diagnosis of cholangiocarcinoma was established. To alleviate jaundice and prolong the overall survival, percutaneous transhepatic cholangiopancreatic drainage (PTCD) was performed. During the operation, segmental stenosis of the extrahepatic bile duct and a vine-like expansion of the intrahepatic bile duct was observed. Furthermore, a biliary biopsy was performed under fluoroscopy to determine the nature and origin of the lesion. The pathological diagnosis of the biopsy was SRCC. Finally, a diagnosis of primary SRCC of extrahepatic bile duct with distant lymph node metastasis and multiple liver metastases was made based on the radiographic, PTCD, and pathological characteristics. The tumor was diagnosed as T3N1M1 stage IV. Despite our aggressive approach, the patient died of liver failure after 1 mo. CONCLUSION This is the only case report on primary SRCC of the extrahepatic bile duct with distant organ metastasis to date.

BACKGROUND Primary hepatic neuroendocrine carcinoma (NEC) is rare, and a combination with hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) is extremely rare. To date, only four combination cases have been reported. The present paper describes the fifth patient. CASE SUMMARY A 32-year-old Chinese man with chronic hepatitis B was hospitalized for persistent upper abdominal pain. Abdominal computed tomography (CT) examination revealed a liver mass. The tumor was located in the 7 th and 8 th segments of the liver, and CT and magnetic resonance imaging findings were consistent with the diagnosis of HCC. Laboratory examinations revealed the following: Alanine aminotransferase, 243 U/L; aspartate aminotransferase, 167 U/L; alpha-fetoprotein, 4519 μg/L. Laparoscopic right lobe hepatectomy was performed on the liver mass. Postoperative pathology showed low differentiation HCC plus medium and low differentiation CCA combined with NEC. One month after the surgery, the patient suffered from epigastric pain again. Liver metastasis was detected by CT, and tumor transcatheter arterial chemoembolization was performed. Unfortunately, the liver tumor was progressively increased and enlarged, and after 1 mo, the patient died of liver failure. CONCLUSION This is a rare case, wherein the tumor is highly aggressive, grows rapidly, and metastasizes in a short period. Imaging and laboratory tests can easily misdiagnose or miss such cases; thus, the final diagnosis relies on pathology.

Primary extraskeletal Ewing sarcoma (EES) is a rare small round cell malignancy that accounts for less than 1% of all sarcomas. It is found most commonly in the trunk and lower limbs and very rarely in the pleura and can be easily misdiagnosed in clinical practice. This study presents the case of an 11-year-old boy who presented to our hospital with no apparent cause of left shoulder pain for 6 months. On physical examination, tenderness was noted in the left chest wall and shoulder joint, which had a limited range of motion. Computed tomography (CT) and magnetic resonance imaging (MRI) of the chest revealed an irregular soft tissue mass in the upper left thorax, with a wide base attached to the adjacent pleura and bone destruction of the adjacent left first rib. The patient’s bone scan showed a dense focus of increased radiotracer accumulation in the left first rib. A subsequent CT-guided aspiration biopsy of the left pleural mass with histomorphology and immunohistochemical phenotyping led to a diagnosis of extraskeletal Ewing sarcoma. To inhibit tumor growth, alternating systemic chemotherapy cycles of vincristine, doxorubicin, and cyclophosphamide (VDC) and isocyclophosphamide and etoposide (IE) were administered at 3-week intervals. After completing three VDC and two IE cycles, the child’s condition was well and the pain in the left shoulder joint was relieved. However, a repeat MRI of the chest showed that the mass did not shrink.