Hemorrhage from metastatic brain epithelioid hemangioendothelioma: A case report.

In this report, we describe a very rare case of metastatic epithelioid hemangio-endothelioma (EHE) originating from other organs such as the lung and requiring craniotomy due to subsequent hemorrhage. A 50-year-old man was diagnosed with EHE in the bilateral lungs, the mediastinum, and the right adrenal gland 8 years earlier. One year earlier, he had developed spinal metastasis. Six months earlier, a screening brain MRI had revealed multiple brain metastases of tumor. He developed subcortical hemorrhage from the tumor in the right parietal lobe and successfully underwent removal of hematoma and tumor. Histopathological examinations revealed EHE. Metastatic EHE is very rare but may be at high risk of intracranial hemorrhage. It is quite important to consider the possibility of brain metastasis and subsequent bleeding when treating patients with EHE.

Dysregulation of Amphiregulin stimulates the pathogenesis of cystic lymphangioma.

Along with blood vessels, lymphatic vessels play an important role in the circulation of body fluid and recruitment of immune cells. Postnatal lymphangiogenesis commonly occurs from preexisting lymphatic vessels by sprouting, which is induced by lymphangiogenic factors such as vascular endothelial growth factor C (VEGF-C). However, the key signals and cell types that stimulate pathological lymphangiogenesis, such as human cystic lymphangioma, are less well known. Here, we found that mouse dermal fibroblasts that infiltrate to sponges subcutaneously implanted express VEGF-D and sushi, Von Willebrand factor type A, EGF, and pentraxin domain containing 1 (SVEP1) in response to PDGFRß signal. In vitro, Pdgfrb knockout (ß-KO) fibroblasts had reduced expression of VEGF-D and SVEP1 and overproduced Amphiregulin. Dysregulation of these three factors was involved in the cyst-like and uneven distribution of lymphatic vessels observed in the ß-KO mice. Similarly, in human cystic lymphangioma, which is one of the intractable diseases and mostly occurs in childhood, fibroblasts surrounding cystic lymphatics highly expressed Amphiregulin. Moreover, fibroblast-derived Amphiregulin could induce the expression of Amphiregulin in lymphatic endothelial cells. The dual source of Amphiregulin activated EGFR expressed on the lymphatic endothelial cells. This exacerbation cascade induced proliferation of lymphatic endothelial cells to form cystic lymphangioma. Ultimately, excessive Amphiregulin produced by fibroblasts surrounding lymphatics and by lymphatic endothelial cells per se results in pathogenesis of cystic lymphangioma and will be a fascinating therapeutic target of cystic lymphangioma.

PDGF receptor signal mediates the contribution of Nestin-positive cell lineage to subcutaneous fat development.

The beiging of white adipose tissue (WAT) is expected to improve systemic metabolic conditions; however, the regulation and developmental origin of this process remain insufficiently understood. In the present study, the implication of platelet-derived growth factor receptor alpha (PDGFRα) was examined in the beiging of inguinal WAT (ingWAT) of neonatal mice. Using in vivo Nestin expressing cell (Nestin+) lineage tracing and deletion mouse models, we found that, in the mice with Pdgfra gene inactivation in Nestin+ lineage (N-PRα-KO mice), the growth of inguinal WAT (ingWAT) was suppressed during neonatal periods as compared with control wild-type mice. In the ingWAT of N-PRα-KO mice, the beige adipocytes appeared earlier that were accompanied by the increased expressions of both adipogenic and beiging markers compared to control wild-type mice. In the perivascular adipocyte progenitor cell (APC) niche of ingWAT, many PDGFRα+ cells of Nestin+ lineage were recruited in Pdgfra-preserving control mice, but were largely decreased in N-PRα-KO mice. This PDGFRα+ cell depletion was replenished by PDGFRα+ cells of non-Nestin+ lineage, unexpectedly resulting in an increase of total PDGFRα+ cell number in APC niche of N-PRα-KO mice over that of control mice. These represented a potent homeostatic control of PDGFRα+ cells between Nestin+ and non-Nestin+ lineages that was accompanied by the active adipogenesis and beiging as well as small WAT depot. This highly plastic nature of PDGFRα+ cells in APC niche may contribute to the WAT remodeling for the therapeutic purpose against metabolic diseases.

Repeated recurrent intracerebral hemorrhage may be involved in cerebral amyloid angiopathy-related inflammation: An autopsy case.

We report an autopsy case of repeated recurrent intracerebral hemorrhage (ICH) diagnosed as having cerebral amyloid angiopathy-related inflammation (CAA-ri) in a 65-year-old woman. She had no history of hypertension or other risk factors for stroke. She had a history of lobar ICH in the right parietal lobe 30 months prior. Follow-up magnetic resonance imaging (MRI) performed 29 months after the initial ICH revealed superficial siderosis in the left frontal lobe. She initially presented with severe headache and dysarthria. An initial computed tomography (CT) revealed a subarachnoid hemorrhage on the left frontal lobe. One hour later, an epileptic seizure occurred, and another CT performed at the time revealed lobar ICH in the frontal lobe. Emergency surgical hematoma evacuation was performed. The cortical artery was removed from the surgical specimen. Hematoxylin and eosin (HE) staining revealed lymphocytic perivascular cuffs, and immunohistochemical staining revealed abundant amyloid-ß (Aß) deposits. The patient was diagnosed as having CAA-ri. On the next day, and 19, 46, 55, 78, 79, and 85 days after admission, ICH recurred. We did not administer immunosuppressive drugs, such as high-dose corticosteroids or cyclophosphamide, because of the patient's condition. Following the last ICH, the patient died on the 90th day after symptom onset. An autopsy was performed. Histologically, abundant Aß deposits were observed within the leptomeningeal and cortical arteries. Further dense-cored amyloid plaques were observed in the cortical samples. Our findings that ICH occurred initially three times in the left hemispheres and later five times in the right hemispheres were considered immune-mediated effects on vascular function. Further, superficial hemosiderosis in the left frontal lobe occurred before the first three ICH events, and hyperintensity of the white matter on MRI was identified in the right parietal lobe, a typical finding of CAA-ri. We hypothesize that the inflammatory process in CAA-ri may be related to recurrent ICH.

Vascular PDGFR-alpha protects against BBB dysfunction after stroke in mice.

Blood-brain barrier (BBB) dysfunction underlies the pathogenesis of many neurological diseases. Platelet-derived growth factor receptor-alpha (PDGFRα) induces hemorrhagic transformation (HT) downstream of tissue plasminogen activator in thrombolytic therapy of acute stroke. Thus, PDGFs are attractive therapeutic targets for BBB dysfunction. In the present study, we examined the role of PDGF signaling in the process of tissue remodeling after middle cerebral arterial occlusion (MCAO) in mice. Firstly, we found that imatinib increased lesion size after permanent MCAO in wild-type mice. Moreover, imatinib-induced HT only when administrated in the subacute phase of MCAO, but not in the acute phase. Secondly, we generated genetically mutated mice (C-KO mice) that showed decreased expression of perivascular PDGFRα. Additionally, transient MCAO experiments were performed in these mice. We found that the ischemic lesion size was not affected; however, the recruitment of PDGFRα/type I collagen-expressing perivascular cells was significantly downregulated, and HT and IgG leakage was augmented only in the subacute phase of stroke in C-KO mice. In both experiments, we found that the expression of tight junction proteins and PDGFRß-expressing pericyte coverage was not significantly affected in imatinib-treated mice and in C-KO mice. The specific implication of PDGFRα signaling was suggestive of protective effects against BBB dysfunction during the subacute phase of stroke. Vascular TGF-ß1 expression was downregulated in both imatinib-treated and C-KO mice, along with sustained levels of MMP9. Therefore, PDGFRα effects may be mediated by TGF-ß1 which exerts potent protective effects in the BBB.

Different PDGF Receptor Dimers Drive Distinct Migration Modes of the Mouse Skin Fibroblast.

BACKGROUND/AIMS: The migration of mesenchymal cells is a fundamental cellular process that has been implicated in many pathophysiological conditions and is induced by chemoattractants such as platelet-derived growth factors (PDGFs). However, the regulatory mechanisms shaping this migration remain to be elucidated. METHODS: Here, we prepared mouse skin fibroblasts inactivated for different PDGF receptor genes and systematically measured their chemotactic responses within a gradient of different chemoattractants. RESULTS: We found that PDGFRαß and PDGFRßß dimers were strong inducers of random and directionally-persistent migration, respectively, that was sustained for up to 24 h. MAPK and PI3K were necessary to mediate random and directional migration, respectively. Directional migration was accompanied by abundant ventral stress fiber formation and consistent cell shape with less frequent formation of branch-like processes. CONCLUSION: This is the first systematic study that characterized the chemotaxis mediated by three-different types of PDGFR dimers in mesenchymal cell migration. Our data demonstrate that PDGFR dimer formation is the critical step to determine the specific mode of fibroblast chemotaxis, while the accompanying cytoskeletal remodeling might contribute to migration persistence.

[A case of gastric follicular lymphoma resected and diagnosed with laparoscopy and endoscopy cooperative surgery].

A woman in her 70s was diagnosed with a protruding mucosa-associated lymphoid tissue (MALT) lymphoma during a secondary health examination. After eradication of Helicobacter pylori, a biopsy revealed gastric follicular lymphoma (FL) and the lesion was still protruding one year later. 18F-fluorodeoxyglucose positron emission tomography showed focal nodular hypermetabolic activity, suggesting that FL may have transformed into a diffuse large B-cell lymphoma. Upper gastrointestinal endoscopy, colonoscopy, and capsule endoscopy showed no other lesions in the gastrointestinal tract, and bone marrow biopsy showed no permeation into the marrow. Therefore, this lesion, which appeared as a submucosal tumor, was limited to the stomach. Laparoscopy and endoscopy cooperative surgery was performed, because it allows for correct pathological diagnosis while removing only a minimal portion of the stomach wall. Histological findings showed follicular structures consisting of abnormal lymphoid cells. Immunohistochemical analysis revealed that neoplastic cells were positive for CD20, CD79a, Bcl-2, CD10, and c-MYC, but negative for CD3, CD5, and cyclin D1. Finally, we diagnosed this lesion as a primary gastric FL.

A 47-Year-Old Man with Advanced Distal Pancreatic Carcinoma and an Initial Partial Response to Chemotherapy Requiring Celiac Axis Reconstruction of the Common Hepatic Artery and Left Gastric Artery.

BACKGROUND Distal pancreatectomy with en bloc celiac artery resection (DP-CAR) is a curative surgical method for locally advanced pancreatic body cancer; however, arterial reconstruction remains controversial in this procedure. This report presents the case of a 47-year-old man with advanced distal pancreatic carcinoma and initial partial response to chemotherapy who required celiac axis reconstruction of the common hepatic artery and left gastric artery. CASE REPORT A 47-year-old man had loss of appetite. He had a 40-mm hypovascular tumor extending from the pancreatic body to the tail, invading around the celiac artery, common hepatic artery, left gastric artery, and splenic artery. We initiated chemotherapy concurrent with chemo-radiotherapy with S-1 administration. After chemo-radiotherapy, computed tomography (CT) showed tumor shrinkage, indicating partial response, but soft tissue CT density surrounding the celiac axis arteries persisted. We conducted conversion surgery. When the common hepatic artery was clamped during surgery, the intrahepatic arterial blood flow reduced; thus, we reconstructed the middle hepatic artery to the common hepatic artery. The left gastric artery was also reconstructed using the second jejunal artery to prevent ischemic gastropathy. Histopathologic examination showed no tumor cells in the specimen; thus, R0 resection was achieved. CONCLUSIONS Arterial reconstruction can be an option for R0 resection in DP-CAR when hepatic arterial blood flow is reduced due to an intraoperative common hepatic artery clamping test.

A rare case of synchronous bilateral epididymal and testicular metastases of urothelial carcinoma of the bladder after intravesical bacillus Calmette-Guérin.

A 68-year-old man was diagnosed with non-muscle-invasive bladder cancer and underwent transurethral resection of the bladder tumor (TURBT) in June 2014. The pathological diagnosis was urothelial carcinoma (UC), Grade 2, pT1. He was treated with intravesical bacillus Calmette-Guérin (BCG) instillation after TURBT. In February 2016, he received anti-tuberculosis treatment for systemic BCG infection, and tuberculosis treatment was continued. In September 2018, he presented with bilateral scrotum swelling and underwent bilateral orchiectomy following a diagnosis of antituberculotics-resistant epididymitis. The pathological findings were metastatic UC of the bilateral epididymis and testis. One months later, fluorodeoxyglucose-positron emission tomography/computed tomography showed para-aortic lymph node and peritoneal metastases. He was treated with chemotherapy of gemcitabine and cisplatin. We herein report a very rare case of synchronous metastatic UC of the bilateral epididymis and testis after intravesical BCG treatment.

Oligodendrogenesis and Myelin Formation in the Forebrain Require Platelet-derived Growth Factor Receptor-alpha.

The platelet-derived growth factor receptor-α (PDGFRα) principally mediates growth factor signals in oligodendroglial progenitors and is involved in oligodendrogenesis and myelinogenesis in the developing spinal cord. However, the role of PDGFRα in the developing forebrain remains relatively unknown. We established a conditional knockout mouse for the Pdgfra gene (N-PRα-KO) using a Nestin promoter/enhancer-driven Cre recombinase and examined forebrain development. The expression of PDGFRα was efficiently suppressed in the Olig2+ cells in N-PRα-KO mice. In these mice, Olig2+ cells were slightly decreased during embryonic periods. The decrease was particularly striking during the postnatal period. The commitment of Pdgfra-inactivated Olig2+ cells to Sox10+ oligodendroglial-lineage was largely suppressed. Surviving Olig2+ cells and Sox10+ cells were distributed widely in the N-PRα-KO mouse brain, similarly to those in control mice until the early neonatal period. After that, these cells were drastically depleted in the forebrain during the second postnatal week. The brains of N-PRα-KO mice were severely hypomyelinated, and these mice died on approximately P17 with motor disturbances. Disturbed axonal fibers and extensively aberrant vascular formations appeared in the postnatal N-PRα-KO mouse brains. After the defective PDGFRα signal in the forebrain, these phenotypes were clearly different from those in the spinal cord that showed defective populations expansion and migration of oligodendroglial lineage and premature myelination, as previously described. In contrast, areas of severe hypomyelination were common to both anatomical sites. PDGFRα was critically involved in the myelination of the forebrain and may differently regulate oligodendroglial lineage between the forebrain and spinal cord.

Powerful Homeostatic Control of Oligodendroglial Lineage by PDGFRα in Adult Brain.

Oligodendrocyte progenitor cells (OPCs) are widely distributed cells of ramified morphology in adult brain that express PDGFRα and NG2. They retain mitotic activities in adulthood and contribute to oligodendrogenesis and myelin turnover; however, the regulatory mechanisms of their cell dynamics in adult brain largely remain unknown. Here, we found that global Pdgfra inactivation in adult mice rapidly led to elimination of OPCs due to synchronous maturation toward oligodendrocytes. Surprisingly, OPC densities were robustly reconstituted by the active expansion of Nestin+ immature cells activated in meninges and brain parenchyma, as well as a few OPCs that escaped from Pdgfra inactivation. The multipotent immature cells were induced in the meninges of Pdgfra-inactivated mice, but not of control mice. Our findings revealed powerful homeostatic control of adult OPCs, engaging dual cellular sources of adult OPC formation. These properties of the adult oligodendrocyte lineage and the alternative OPC source may be exploited in regenerative medicine.

Imaging findings of gastric calcifying fibrous tumour.

Calcifying fibrous tumours (CFTs) are rare benign lesions that usually affect the soft tissues, the mesentery and the peritoneum. Gastric CFT is particularly rare. Here, we report a CFT found incidentally in a 31-year-old male. The mass was well circumscribed and showed partial calcification on the CT scan, with dark signal intensity seen on T2 weighted MRI. To the best of our knowledge, there is very limited published information concerning imaging findings of CFTs. We discuss the CT scan and MRI findings of this patient, which can be considered typical for gastric CFT, and present a review of the limited literature available.