Plasma-assisted molecular beam epitaxy of SnO(001) films: Metastability, hole transport properties, Seebeck coefficient, and effective hole mass

Transparent conducting or semiconducting oxides are important materials for (transparent) optoelectronics and power electronics applications. While most of these oxides can be doped n-type only with room-temperature electron mobilities on the order of 100cm^2/Vs p-type oxides are needed for the realization of pn-junction devices but typically suffer from exessively low (<<1cm^2/Vs) hole mobilities. Tin monoxide (SnO) is one of the few p-type oxides with a higher hole mobility, lacking a well-established understanding of its hole transport properties. Moreover, growth of SnO is complicated by its metastability with respect to SnO2 and Sn, requiring epitaxy for the realization of single crystalline material typically required for high-end applications. Here, we give a comprehensive account on the epitaxial growth of SnO, its (meta)stability, and its thermoelectric transport properties in the context of the present literature. Textured and single-crystalline, unintentionally-doped p-type SnO(001) films are grown by plasma-assisted molecular beam epitaxy. The metastability of this semiconducting oxide is addressed theoretically through an equilibrium phase diagram. Experimentally, the related SnO growth window is rapidly determined by an in-situ growth kinetics study as function of Sn-to-O-plasma flux ratio and growth temperature. The presence of secondary Sn and SnOx (1 < x <= 2) phases is comprehensively studied by different methods, indicating the presence of Sn3O4 or Sn as major secondary phases, as well as a fully oxidized SnO2 film surface. The hole transport properties, Seebeck coefficient, and density-of-states effective mass are determined and critically discussed in the context of the present literature on SnO, considering its anisotropic hole-effective mass

Malignant peripheral nerve sheath tumor associated with neurofibromatosis type 1, with metastasis to the heart: a case report

A rare case is presented of a 61-year-old man with a malignant peripheral nerve sheath tumor associated with neurofibromatosis type 1, with metastasis to the heart. The primary tumor originated in the right thigh in 1982. Since then, the patient has had repeated local recurrences in spite of repeated surgical treatment and adjuvant chemotherapy. He has developed previous metastases of the lung and heart. The patient died of cardiac involvement

Early uptake and continuous accumulation of thallium-201 chloride in a benign mixed tumor of soft tissue: Case Report

A case of benign mixed tumor of the soft tissue in a 64-year-old Japanese male is presented. He noticed a painless, elastic hard mass sized 3 cm in the right knee, which gradually grew larger and harder in the last 5 years. Magnetic resonance imaging demonstrated a mass lesion embedded in the subcutaneous tissue with low and high signal intensity at T1- and T2-weighted images, respectively. Tl-201 scintigraphy showed an early uptake of Tl-201 within the lesion at 10 minutes after injection, which was slightly decreased but still continued at 2 hours later. The patient underwent a resection of tumor, and the pathological diagnosis was a benign mixed tumor of soft tissue without high vascularity, characterized by histological features similar to pleomorphic adenomas in the salivary glands. Immunohistochemical study proved expression of Na(+)/K(+)-ATPase of tumor cells. Overexpression of Na(+)/K(+)-ATPase of the tumor might be responsible for the early uptake of Tl-201, and poor vascular structure in this tumor might lead to continuous accumulation. The Tl-201 scintigraphic features of mixed tumor of soft tissue are assessed to resemble those of malignant soft tissue tumors

Subserosal Inflammatory Pseudotumor Causing Intussusception

We present an adult case of intussusception caused by subserosal inflammatory pseudotumor of the terminal ileum. Enteric intussusception was diagnosed by characteristic Xray finding, so called "beak-like" filling defect in the terminal ileum. An exploratory laparotomy revealed focal subserosal thickening in the terminal ileum, and partial ileocolectomy was performed. Microscopically, we identified a pseudotumor that extended through the muscularis propria into serosa. The pseudotumor was composed of fibrous stroma and chronic inflammatory cells with calcification

Relationship between band-offset, gate leakage current, and interface states density at SiO2/4H-SiC (000-1) interface

We investigated the relationship between the band-offset, the gate leakage current, and the interface states density on SiO2/4H-SiC (000-1) structures via hard x-ray photoelectron spectroscopy and electrical measurements. From the observed band-offset, we found that conduction band offset (ΔEc) depended on the oxidation procedure, but valence band-offset (ΔEv) did not. In addition, ΔEv was larger than ΔEc, indicating that electron tunneling was more predominant than hole tunneling. SiO2 prepared by a dry oxidation procedure exhibited the highest gate leakage current onset and the highest interface states density and the largest ΔEc, whereas a wet oxidation procedure produced the lowest gate leakage current onset, the lowest interface states density, and the smallest ΔEc. Oxygen annealing after wet oxidation effectively increased gate leakage current onset, which increased the interface states density and the ΔEc. These results were related to hydrogen atoms and carbon related defects at the SiO2/4H-SiC (000-1) interface

Primary Fallopian Tube Carcinoma Presenting with a Massive Inguinal Tumor: A Case Report and Literature Review

Primary fallopian tube carcinoma (PFTC) has characteristics similar to those of ovarian carcinoma. The typical course of PFTC metastasis includes peritoneal dissemination and pelvic and paraaortic lymph node metastasis, while inguinal lymph node metastasis is rare. Moreover, the initial presentation of PFTC with an inguinal tumor is extremely rare. A 77-year-old postmenopausal woman presented with a massive 12-cm inguinal subcutaneous tumor. After tumor resection, histopathological and immunohistochemical analysis showed that the tumor was a high-grade serous carcinoma of gynecological origin. Subsequent surgery for total hysterectomy with bilateral salpingo-oophorectomy revealed that the tumor developed in the fallopian tube. She received adjuvant chemotherapy with carboplatin and paclitaxel, followed by maintenance therapy with niraparib. There has been no recurrence or metastasis 9 months after the second surgery. We reviewed the literature for cases of PFTC and ovarian carcinoma that initially presented with an inguinal tumor. In compliance with the Preferred Reporting Items for Systematic Reviews guidelines, a systematic literature search was performed through 31 January 2022 using the PubMed and Google scholar databases and identified 14 cases. In half of them, it was difficult to identify the primary site using preoperative imaging modalities. Disease recurrence occurred in two cases; thus, the prognosis of this type of PFTC appears to be good

Late recurrence of pStage 1 low-grade serous ovarian tumor presenting as a symptomatic bone metastasis: a case report

Abstract Background Ovarian serous borderline tumor/atypical proliferative serous tumor (SBT/APST) is characterized by presenting at an early stage and much longer survival than high-grade serous carcinoma. Given that the prognosis of ovarian SBT/APST with no invasive features is excellent, remote relapse after surgery can pose a diagnostic pitfall. Bone metastasis as transformed low-grade carcinoma is an extremely rare initial presentation of recurrence in patients whose primary tumor was confined to the ovaries. Case presentation A 55-year-old Japanese woman who had undergone surgery for a right ovarian tumor 13 years previously presented with right-lateral chest pain and neurologic abnormalities in the lower limbs. Computed tomography (CT) scan and magnetic resonance imaging revealed an irregular mass in the right arch of the 12th thoracic vertebra, extending through the intervertebral foramen and into surrounding soft tissue, the maximum diameter of the whole mass being 78 mm. Pathological examination of a CT-guided needle biopsy of the paraspinal lesion demonstrated papillary cell clusters with blunt nuclear atypia and psammomatous calcification that were positive for PAX8, estrogen receptor, and WT1, but negative for thyroglobulin on immunohistochemical testing, and of a P53 non-mutational pattern. On clinicopathologic review, the previous 13- × 11- × 9-cm ovarian tumor was an intracystic and exophytic papillary growth without surface involvement; it had ruptured intraoperatively. Microscopically there was serous epithelium with minimal cytologic atypia proliferating in hierarchical branches with no invasive foci or micropapillary components. The tumor was confined to the right ovary with no peritoneal implants. Neither primary nor metastatic tumor harbored KRAS/BRAF mutations according to polymerase chain reaction using formalin-fixed paraffin-embedded tissues. We concluded that, after a 13-year disease-free interval, the paraspinal lesion was bone metastasis of low-grade carcinoma originating from the ovarian SBT/APST. The patient received radiotherapy for the paraspinal lesion followed by administration of paclitaxel and carboplatin plus bevacizumab and remains alive 168 months after the initial surgery. Conclusions Pathologists and radiologists should not exclude late recurrence of ovarian SBT/APST when bone metastases are suspected, even when neither peritoneal nor lymph node involvement are detected. Long-term surveillance of women with ovarian serous tumors with no invasive features is recommended

Rectotumoral fistula formation occurring more than 5 years after carbon ion radiotherapy for sacral chordoma: A case report

Chordoma is a rare tumor that originates from the notochord. Half of chordomas involve the sacral region. Surgery is considered to be the standard treatment for sacral chordoma. However, carbon ion radiotherapy (CIRT) has recently emerged as a promising treatment for unresectable sacral chordoma. Little is known about the long-term complications of CIRT. We present two cases of rectotumoral fistula formation that occurred >5 years after CIRT for sacral chordoma. We considered two possible explanations for fistula formation: radiation enterocolitis after CIRT might cause formation of the fistula long-term, and tumor regrowth might compress the rectum and cause fistula formation. A biopsy in Case 1 showed that regrowth tumor was post-CIRT. It is important to be aware of the possibility of rectal complications after CIRT, and if found, resection of the rectum should be considered. This is a first report of rectotumoral fistula formation that occurred >5 years after CIRT for sacral chordoma

Microinvasion of High-Grade Pancreatic Intraepithelial Neoplasia

High-grade pancreatic intraepithelial neoplasia (PanIN-3) is recognized as a precursor lesion of invasive ductal carcinoma (IDC). However, histological evidence that PanIN-3 invades beyond the basement membrane of pancreatic ductal epithelium, that is, the moment PanIN-3 becomes IDC, has not been captured yet. This may be because PanINs which are microscopic papillary or flat lesion rarely develop clinical symptoms and are not detectable on imaging examination. On the other hand, most IDCs were found in the advanced stage with massive invasion. In this report, PanIN-3 obstructed several branch pancreatic ducts and subsequently caused pancreatitis which developed clinical symptom and was detectable as a pancreatic mass in imaging studies. A 65-year-old woman was referred to our institution for further examination of her repeated pancreatitis. Abdominal ultrasound revealed a low echoic mass of 13 mm in diameter in the pancreatic body without upstream dilatation of the main pancreatic duct (MPD). Endoscopic retrograde pancreatography showed a strictured segment of 2 mm in length in the MPD at the pancreatic body. Cytological examination of pancreatic juice revealed adenocarcinoma and distal pancreatectomy was performed. A resected specimen revealed a whitish mass of 15 mm in diameter in the pancreatic body, which was identified as pancreatitis by histological examination. Papillary growth of PanIN-3 was seen mainly in the branch ducts. Each PanIN-3 was located separately in the branch ducts with normal epithelia in the MPD between them. In three adjacent branch ducts, PanIN-3 was observed to be invading microscopically beyond the basement membrane