Effect of electron beam irradiation in gas atmosphere during ETEM.

Transmission electron microscopy (TEM) is used to observe the atomic structures of materials. Environmental TEM (ETEM) is a method wherein a gas can be evaluated and it has been used to observe the dynamic reaction between materials and gases at the atomic level. An electron beam (EB), which has a sufficiently high energy (exceeding a few tens of kilovolts), can be used to ionize gas molecules. Subsequently, the ionized molecules might react with the materials during ETEM. Therefore, the current generated by the ions and electrons were measured to verify the presence of ions generated due to the ionization of the N2 gas atmosphere during EB irradiation in ETEM. The electron energy loss spectra (EELS) were acquired from the N2 gas atmosphere to estimate the types of ions generated. The results demonstrated that ions and electrons were generated in the N2 atmosphere during ETEM and EB irradiation. Moreover, the EELS analysis indicated that the generated ion was N2+. The material observation conducted using gas ETEM can detect the reaction between gases, ions, and materials.

Fatal case of pancreatic panniculitis caused by occult neuroendocrine tumor in the corresponding organ: A case report and review of the published work.

Pancreatic panniculitis (PP) is a rare clinical variant of subcutaneous fat necrosis, developing in patients with a variety of pancreatic diseases such as acute or chronic pancreatitis, tumors and cysts. The tumor-associated PP represents a noteworthy skin manifestation of underlying internal malignancies, also known as dermadrome. Among causative pancreatic tumors, acinar cell carcinoma is the most frequent malignancy; however, little is known about how the origin of tumor cells and progression stage of pancreatic tumors potentially contribute to the establishment of panniculitis. Here, we present a 69-year-old Japanese male case of clinically aggressive PP on the bilateral legs, whose skin lesions developed prior to the diagnosis of occult pancreatic tumor and liver metastasis. Moreover, the immunopathology of the pancreatic lesion revealed neuroendocrine tumor (NET), a rare pathological variant. Skin lesions immediately spread to the upper limbs with extensive ulcerations and necrosis, accompanied by high levels of serum lipase and elastase, but not with other pancreatic enzymes. He died 2 months after the initial development of the skin lesion due to rapid deterioration of general condition. We reviewed 14 cases, including ours, of PP with NET in the pancreas thus far reported, to identify the clinicopathological characteristics regarding to what extent this rare complication could reflect the clinical course of pancreatic tumors and overall prognosis. Our published work review found that the disease has a significant male predominance (male : female, 13:1) and cases with occult pancreatic tumors died within 4 months after the development of their skin lesions. Our case was the poorest prognostic outcome. This report emphasizes that dermatologists should recognize PP with NET, reflecting a fatal prognosis, and to make a prompt diagnosis.

[A case of recurrent lymph node metastases of advanced colon cancer with penetration of the gastric wall, treated effectively by cetuximab monotherapy as third-line treatment].

A 45-year-old man was first treated for lymph node metastases of colon cancer with FOLFIRI. After 13 courses, the lymph node metastases worsened, and he was treated with mFOLFOX6 plus bevacizumab as the second-line chemotherapy. After 8 courses, his anorexia and anemia became increasingly troublesome. We diagnosed this as the direct invasion of lymph node metastases to the gastric wall. As the third-line chemotherapy, cetuximab monotherapy was applied. The gastric ulcer lesion then began healing as a scar. In our progressive case, cetuximab monotherapy was effective as a third-line treatment.

[A case of rectal GIST treated with imatinib mesylate neoadjuvant therapy to preserve the anus].

A 64-year-old man was admitted to our hospital with anal pain on evacuation. MRI revealed a large rectal submucosal tumor, more than 6 cm in diameter. Fine needle histological diagnosis indicated GIST with moderate risk. The patient was treated with imatinib mesylate in order to preserve the anus. The anal pain and tumor size decreased. Trans-anal local excision was performed. This case suggests that imatinib mesylate can make it possible to treat large rectal GIST cases by preserving anus, if neoadjuvant chemotherapy can be effective.