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ABSTRACT: A 40-year-old woman presented with dull, boring periumbilical region pain radiating to the back and vomiting for 1 year. Magnetic resonance cholangiopancreatography detected a polypoid growth in the ampullary region. The patient underwent Whipple's procedure. The specimen revealed a 4.9 × 4.5 × 3.7 cm tumor arising from the pancreas, abutting the posterior pancreatic surface and infiltrating the terminal common bile duct and the ampulla. Microscopic examination showed a pancreatic tumor composed of neuroendocrine cells. In addition, many large foci showing solid sheets of oncocytic cells with abundant granular eosinophilic cytoplasm were observed. Immunohistochemistry studies revealed positivity for synaptophysin, chromogranin, and Ki67 index above 70%. A diagnosis of oncocytic neuroendocrine tumor of Grade 3 was made. In electron microscopy, oncocytic cells showed abundant mitochondria dispersed throughout the cytoplasm. Oncocytic pancreatic neuroendocrine neoplasms are uncommon and can be diagnosed only on histopathological examination. These tumors tend to show a malignant behavior.
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Histiocytic sarcoma (HS) is an exceedingly rare lymphohematopoietic malignancy with morphological and immunophenotypic characteristics of mature tissue histiocytes. We report a unique case of a HS with synchronous skin and gastrointestinal tract involvement which has not been reported in literature till date to the best of our knowledge. A 70-year-old male farmer presented with multiple ulcerated skin lesions ranging from 0.5 to 10 cm all over the body. Autopsy revealed multiple transmural nodular deposits in stomach, intestines, head of pancreas, and peripancreatic tissue. Histopathology and immunohistochemistry profile was consistent with HS exhibiting positivity for CD68, CD163, and lysozyme. CD 163 identifies histiocytic malignancies with high degree of specificity and has become a promising marker for their diagnosis.
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Underwater robot designs inspired by the behavior, physiology, and anatomy of fishes can provide enhanced maneuverability, stealth, and energy efficiency. Over the last two decades, robotics researchers have developed and reported a large variety of fish-inspired robot designs. The purpose of this review is to report different types of fish-inspired robot designs based upon their intended locomotion patterns. We present a detailed comparison of various design features like sensing, actuation, autonomy, waterproofing, and morphological structure of fish-inspired robots reported in the past decade. We believe that by studying the existing robots, future designers will be able to create new designs by adopting features from the successful robots. The review also summarizes the open research issues that need to be taken up for the further advancement of the field and also for the deployment of fish-inspired robots in practice.
