[Resection of the Acinar Cell Carcinoma of the Pancreas with Lymph Node Recurrence along the Lesser Curvature of the Stomach-A Case Report].

A 78-year-old woman had undergone subtotal stomach-preserving pancreatoduodenectomy for acinar cell carcinoma (ACC)of the pancreatic head approximately 2 years before presentation, and the pathological diagnosis had been pT2pN0pM0, fStageⅠB(JPS 7th). Adjuvant chemotherapy was discontinued after 3 months because of side effects. Contrast- enhanced CT and PET-CT 2 years postoperatively revealed a tumor measuring 2 cm with a high concentration of FDG in the minor curvature of the stomach. During laparotomy, a 3 cm large lymph node was palpated in the minor curvature of the stomach, and a small lymph node was found adjacently. We diagnosed the patient with multiple lymph node recurrences and performed gastric lymph node dissection of the minor curvature. The pathological diagnosis was a single 2 cm large ACC lymph node metastasis. The patient did not consent to postoperative adjuvant chemotherapy and showed no recurrence for 1 year and 7 months postoperatively. Pancreatic ACC is a rare pancreatic tumor, and its clinicopathologic features are still largely unknown. In recent years, there have been reports of active resection or long-term survival with anti-cancer drug treatment even in recurrent cases, such as the present case. However, the indication and method of anti-cancer treatment are unclear and might need the accumulation of many more cases.

Variable region of betanodavirus RNA2 is sufficient to determine host specificity.

Betanodaviruses, the causative agents of viral nervous necrosis in marine fish, have bipartite positive-sense RNA genomes. The viruses have been classified into 4 distinct types based on nucleotide sequence similarities in the variable region (the so-called T4 region) of the smaller genomic segment RNA2 (1.4 kb). Betanodaviruses have marked host specificity, although the primary structures of the viral RNAs and encoded proteins are similar among the viruses. We have previously demonstrated, using reassortants between striped jack nervous necrosis virus (SJNNV) and redspotted grouper nervous necrosis virus (RGNNV), that RNA2, which encodes the coat protein, strictly controls host specificity. However, because RNA2 is large, we were unable to propose a mechanism underlying this RNA2-based host specificity. To identify the RNA2 region that controls host specificity, we constructed RNA2 chimeric viruses from SJNNV and RGNNV and tested their infectivity in the original host fish, striped jack Pseudocaranx dentex and sevenband grouper Epinephelus septemfasciatus. Among these chimeric viruses, SJNNV mutants containing the variable region of RGNNV RNA2 infected sevenband grouper larvae in a manner similar to RGNNV, while RGNNV mutants containing the variable region of SJNNV RNA2 infected striped jack larvae in a manner similar to SJNNV. Immunofluorescence microscopic studies using anti-SJNNV polyclonal antibodies revealed that these chimeric viruses multiplied in the brains, spinal cords and retinas of the infected fish, as in infections by the parental viruses. These results indicate that the variable region of RNA2 is sufficient to control host specificity in SJNNV and RGNNV.