A case of hepatic anisakidosis caused by Anisakis pegreffii mimicking liver cancer.

Extra-gastrointestinal anisakidosis is rare. We herein report an Anisakis pegreffii infection in a patient with hepatic anisakidosis diagnosed based on its molecular identification. A 71-year-old male patient had a hepatic tumor presenting as a low-density area of 20 mm in diameter in segment 6 of the liver on abdominal ultrasonography, computed tomography, and magnetic resonance imaging. The surgically resected pathological specimen revealed a necrotizing eosinophilic granuloma containing nematode larvae, possibly an Anisakis larva. Molecular and phylogenetic analysis demonstrated Anisakis larvae belonging to A. pegreffii. The present results will help identify and characterize unknown Anisakis species in histological sections.

Primary Pulmonary Myxoid Sarcoma with EWSR1::ATF1 Fusion: A Case Report.

Primary pulmonary myxoid sarcoma is a rare lung sarcoma, mostly involving the central lung and harboring the EWSR1::CREB1 fusion. We report an exceptional case of primary pulmonary myxoid sarcoma arising in the peripheral lung and harboring an EWSR1::ATF1 gene fusion. A 67-year-old man presented with a solid nodule in the right lower lobe, and wedge resection was performed. Microscopically, the tumor consisted of reticular proliferation of uniform mildly atypical spindle cells within abundant myxoid stroma. Immunohistochemically, smooth muscle actin was positive but desmin was negative. Fluorescence in situ hybridization confirmed EWSR1 and ATF1 gene rearrangements. No recurrence was seen for 12 months. Pathological findings and gene rearrangements are important for the diagnosis of primary pulmonary myxoid sarcoma. Complete resection and careful observation are required.

Mesectodermal Leiomyoma of the Ciliary Body: A Unique Variant of Leiomyoma with Myogenic and Neurogenic Histological Features.

Mesectodermal leiomyoma of the ciliary body is a rare benign tumor, showing both neurogenic and myogenic characteristics. This tumor typically shows predilection for women of reproductive age. Because it is almost impossible to clinically distinguish this tumor from malignant melanoma, unnecessary eye enucleations have been unfortunately performed. Herein, we report a case of mesectodermal leiomyoma of the ciliary body in a young Japanese woman. She was referred to our hospital due to a slow-growing mass in her left iris. A malignant tumor could not be clinically ruled out and surgery with intraoperative pathology consultation was performed. Intraoperative frozen section diagnosis was a benign tumor with neurogenic features, and a simple excision of the tumor was performed. Histologically, the tumor was composed of diffuse growth of spindle cells with fibrillary indistinctive cytoplasm. Immunohistochemical examination showed diffuse positive staining of α-smooth muscle actin, h-caldesmon, calponin, and CD56. Scattered tumor cells were weakly positive for desmin. Neither melanocytic markers nor neural markers except for CD56 were positive. We diagnosed this tumor as mesectodermal leiomyoma. Mesectodermal leiomyoma is rare and often misdiagnosed as malignant melanoma. To avoid overtreatment, a correct preoperative diagnosis is essential.

Aggressive advanced gastric cancer in a patient with autosomal dominant polycystic kidney disease.

A 60-year-old man with autosomal dominant polycystic kidney disease presented with malaise, melena, and epigastric discomfort. Esophagogastroduodenoscopy revealed a massive elevated gastric cancer lesion involving the cardia. Histopathological evaluation of a biopsy specimen showed poorly differentiated adenocarcinoma. Fluorodeoxyglucose-positron emission tomography revealed significant fluorodeoxyglucose uptake in the stomach, liver, bones, and bone marrow. He was diagnosed with metastatic gastric cancer resistant to chemotherapy, and he developed bone marrow carcinomatosis and disseminated intravascular coagulation and died 8 weeks after disease onset. A statistically significant association is reported between autosomal dominant polycystic kidney disease and gastric cancer. Moreover, the specific clinical features observed in our patient could be attributed to the molecular disorders like PC-1 and mechanistic target of rapamycin that are known to occur in autosomal dominant polycystic kidney disease.

Deep-UV excitation fluorescence microscopy for detection of lymph node metastasis using deep neural network.

Deep-UV (DUV) excitation fluorescence microscopy has potential to provide rapid diagnosis with simple technique comparing to conventional histopathology based on hematoxylin and eosin (H&E) staining. We established a fluorescent staining protocol for DUV excitation fluorescence imaging that has enabled clear discrimination of nucleoplasm, nucleolus, and cytoplasm. Fluorescence images of metastasis-positive/-negative lymph nodes of gastric cancer patients were used for patch-based training with a deep neural network (DNN) based on Inception-v3 architecture. The performance on small patches of the fluorescence images was comparable with that of H&E images. Gradient-weighted class activation mapping analysis revealed the areas where the trained model identified metastatic lesions in the images containing cancer cells. We extended the method to large-size image analysis enabling accurate detection of metastatic lesions. We discuss usefulness of DUV excitation fluorescence imaging with the aid of DNN analysis, which is promising for assisting pathologists in assessment of lymph node metastasis.