Proliferative Vascular Lesions Research Articles

A case report of nasal lobular capillary hemangioma and its management

Nasal lobular capillary hemangioma is a benign vascular lesion marked by epistaxis and nasal obstruction. The nasal cavity is a relatively rare location as lobular capillary hemangiomas commonly occur in the oral cavity. They are termed as lobular capillary hemangioma based on the histopathological features of anastomosing capillary networks arranged in lobular architechture. We report a case of 40 year old female with history of left nasal obstruction and recurrent epistaxis since 2 months. Examination of nose revealed a protruding reddish coloured mass on the left side and CT scan of nose and paranasal sinuses showed the mass arising from the anterior part of nasal septum along with nasal spur. Patient underwent surgical excision of the mass along with spur removal under general anesthesia. Histopathology demonstrated vascular proliferative lesion consistent with hemangioma. The diagnosis of capillary hemangioma must always be taken into account while considering the differential diagnosis of bleeding mass in the nasal cavity.

A case of pseudo-Kaposi sarcoma with chronic limb-threatening ischemia

BackgroundPseudo-Kaposi sarcoma (PKS) is a rare vascular proliferative disease, caused by arteriovenous malformation (AVM) and chronic venous insufficiency. The lesions are characterized by purple or reddish-brownish papules, plaques, and nodules. Although benign, it is clinically similar to Kaposi's sarcoma (KS), a malignant disease, and must be differentiated by histopathological examination. We report a rare case of PKS with chronic limb-threatening ischemia (CLTI).Case presentationAn 83-year-old man with diabetes mellitus (DM) presented to a local dermatology department with a complaint of a right second toe ulcer and was, thereby, referred to our department due to arterial bleeding during skin biopsy to exclude malignant diseases. Although the pulsation of dorsalis pedis artery of the affected limb was palpable, the skin perfusion pressure was only 20 and 30 mmHg on the dorsum and planter surface, respectively, indicating severe ischemia of toe and forefoot. Ultrasonography and computed tomography revealed an AVM around the right second metatarsophalangeal joint and occlusion of the right dorsalis pedis artery in the middle, indicating CLTI in the background. Pathological findings of the skin biopsy found capillary blood vessel proliferation, hemosiderin deposition, and extravascular red blood cell leakage in the dermal layer, which could be found in KS. However, CD34 was normally stained in the vascular endothelium, and human herpesvirus-8 staining was negative, resulting in the pathological diagnosis of PKS, a proliferative vascular lesion associated with AVM. The ulcer was spontaneously epithelialized, but 2 years later the ulcer recurred and infection developed, necessitating treatment for abnormal blood flow. Transarterial embolization using N-butyl 2-cyanoacrylate for the AVM controlled abnormal perfusion once; however, the procedure exacerbated perfusion of the toe, resulting in foot ulcer progression. Forefoot amputation with surgical excision of AVM was performed, and thereby, wound healing was achieved.ConclusionThis is a rare case of PKS with CLTI complicated with AVM. As there is currently no established consensus on the treatment of PKS, the approach to treatment strategy should be tailored to the specific condition of each patient.

Mechanisms of persistent hemolysis-induced middle kidney injury in grass carp (Ctenopharyngodon idella)

Infection-induced hemolysis results in intravascular hemolysis, which releases hemoglobin (Hb) into the tissues. Free Hb exhibits cytotoxic, oxidative, and pro-inflammatory effects, leading to systemic inflammation, vascular constriction dysfunction, thrombosis, and proliferative vascular lesions. Currently, the impact of intravascular hemolysis on the middle kidney in fish is unclear. Here, the injection of phenylhydrazine (PHZ) was used to establish a persistent hemolysis model in grass carp. The determination results revealed that the PHZ-induced hemolysis caused conspicuous tissue damage in the kidneys of grass carp, increased the levels of Cr in the serum and the expression indicators of kidney injury-related genes in the middle kidney. Prussian blue staining indicated that PHZ-induced hemolysis significantly increased the deposition of iron ions in the kidneys of grass carp, and activated the expression levels of iron metabolism-related genes. The results of oxidative damage-related experiments indicate that under PHZ treatment, the activity of middle kidney cells decreases, and the production of oxidative damage markers malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE) increases, simultaneously inhibiting the activity of antioxidant enzymes and upregulating the transcription levels of antioxidant enzyme-related genes. Additionally, the analysis of inflammatory factors revealed a significant upregulation of genes associated with inflammation induced by PHZ-induced hemolysis. The transcriptome analysis was performed to further explore the molecular regulatory effects of hemolysis on tissues, the analysis revealed the treatment of PHZ activated various of programmed cell death (PCD) pathways, including ferroptosis, apoptosis, and autophagy. In summary, this study found that sustained hemolysis in fish results in Hb and iron ion deposition in middle kidney, promoting oxidative damage, ultimately inducing various forms of PCD.

Histophilus somni disease conditions with simultaneous infections by ovine gammaherpesvirus 2 in cattle herds from Southern Brazil.

This report investigated the cause of cattle mortality in two farms in Southern Brazil. The tissues of one animal from each farm (animals #1 and #2) respectively were used inpathological and molecular investigations to determine the possible cause of death. The principal pathological findings observed in animal #1 were pulmonary, myocardial, and encephalitic hemorrhages with vasculitis, and lymphoplasmacytic interstitial pneumonia with proliferative vascular lesions (PVL). The main pathological findings observed in animal #2 were purulent bronchopneumonia, hemorrhagic myocarditis, and lymphoplasmacytic interstitial pneumonia with PVL. An immunohistochemical assay detected intralesional antigens of a malignant catarrhal fever virus (MCFV) from multiple tissues of animal #2 while PCR confirmed that the MCFV amplified was ovine gammaherpesvirus 2 (OvGHV2), genus Macavirus, subfamily Gammaherpesvirinae; OvGHV2 was also amplified from multiple tissues of animal #1. Furthermore, PCR assays amplified Histophilus somni DNA from multiple fragments of both animals. However, the nucleic acids of Mannheimia haemolytica, Pasteurella multocida, Mycoplasma bovis, bovine respiratory syncytial virus, bovine alphaherpesvirus virus 1 and 5, bovine coronavirus,and bovine parainfluenza virus 3 were not amplified from any of the tissues analyzed, suggesting that these pathogens did not participate in the development of the lesions herein described. These findings demonstrated that both animals were concomitantly infected by H. somni and OvGHV2 and developed the septicemic and encephalitic manifestations of H. somni. Furthermore, theinterstitial pneumonia observed in cow #2 was more likely associated with infection by OvGHV2.

Pyogenic granuloma of eyelid: A literature review and case report

Pyogenic granuloma is an acquired vascular proliferative lesion with associated inflammation, affecting the skin and mucous membranes more frequently. Ocular pyogenic granulomas are rare, involving adnexa, conjunctiva, and cornea. Eyelid pyogenic granuloma is uncommon, associated with chalazion, lid surgeries, lacrimal sac procedures, trauma, predisposing cutaneous lesions, congenital capillary malformations, and idiopathic. We report a case of a 40-year-old male patient who attended our outpatient department with right eye upper lid painless growth, gradually increasing in size in the last two months. The differential diagnosis was burst chalazion, capillary haemangioma, molluscum contagiosum, pilomatricoma, basal cell carcinoma, squamous cell carcinoma, and Kaposi's sarcoma. The lesion was surgically excised, and histopathological examination confirmed the diagnosis. There was no recurrence. This present case illustrates the importance of considering benign inflammatory causes in the differential diagnosis of eyelid mass lesions to avoid unnecessarily aggressive intervention.

Multiple, Eruptive and Generalised Lobular Capillary HaemangiomasA Rare Morphological Variant

Lobular Capillary Haemangioma or Pyogenic Granuloma (PG) is a common benign, vascular proliferative lesion, usually occurring at sites of preceding trauma. It is known to occur more commonly in children and young females. The most common presentation is a solitary lesion. Multiple, eruptive PG have been reported after antecedent burns, trauma and following retinoid therapy and as satellite lesions after treatment of a primary lesion. A 14-year-old female, without any co-morbidities presented with spontaneous onset of multiple, eruptive and generalised skin coloured papules and nodules over face, neck, upper chest and upper back. The lesions were eruptive in nature, involved the back, face and upper trunk over duration of 4 months. There was intermittent bleeding from the lesions after trivial trauma. Clinical diagnosis of lobular capillary haemangioma was confirmed by histopathology which showed lobules of variably dilated network of blood filled capillaries in the papillary dermis surrounded by typical epithelial collarette. The lesions were removed by Radiofrequency (RF) in subsequent sittings. This case report features an interesting and unusual morphological presentation of generalised eruptive lobular capillary haemangioma, which occurred de novo in a young female without any associated skin or systemic disease.

A splenic hamartoma: Adding a new case to the literature: A case report.

IntroductionSplenic tumours are relatively rare and include malignancies such as lymphomas, angiosarcomas, plasmacytomas, primary malignant fibrous histiocytomas, and splenic metastases. Benign tumours of the spleen such as hemangiomas, cysts, and inflammatory pseudotumours are very rare (Kaza et al., 2010, PisaniCeretti et al., 2012) [1], [2]. There are fewer than 160 cases of splenic hamartoma or splenomas having been reported in the literature (Basso et al., 2012) [3]. Only 20% of the cases were detected in children (Abramowsky et al., 2004) [4]. Although multi-modality imaging findings were described preoperatively, the final diagnosis was splenic hamartoma based on histology and immunohistochemistry.Case reportHere, we report a case of a14 year old child left upper quadrant abdominal pain and worsening sickness. Multi-modality imaging detected a solid lesion of the spleen, who required splenectomy and was pathologically diagnosed as a splenic hamartoma. The postoperative course was uneventful.DiscussionSplenic hamartoma is very rare. Only 20% of hamartomas occur in children. They are commonly found incidentally on imaging with no symptoms.ConclusionSplenic hamartoma is a benign vascular proliferative lesion that requires a multi-modality imaging studies for diagnosis and confirmed by histopathology. It must be included in the differential diagnosis of splenic mass forming lesions.

The Participation of a Malignant Catarrhal Fever Virus and Mycoplasma bovis in the Development of Single and Mixed Infections in Beef and Dairy Cattle With Bovine Respiratory Disease.

The bovine respiratory disease (BRD) complex is a multietiological and multifactorial disease associated with a wide range of viral and bacterial pathogens. This study evaluated the contribution of specific infectious disease agents in the development of BRD in cattle from Brazil and determined if a virus within the malignant catarrhal fever virus (MCFV) group and Mycoplasma bovis, acting individually or in conjunction, can be associated with the development of BRD. Formalin-fixed paraffin-embedded pulmonary sections were used in immunohistochemical assays to determine the intralesional presence of six antigens associated with BRD: bovine alphaherpesvirus 1 (BoHV-1), bovine parainfluenza virus 3 (BPIV-3), bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), MCFV, and M. bovis. Pneumonia was diagnosed in 82.7% (120/145) of all cattle evaluated. Interstitial pneumonia (60%, 72/120) and suppurative bronchopneumonia (25.8%, 31/120) were the most frequent patterns of pneumonia identified. Intralesional antigens of MCFV (53.3%, 64/120) were the most frequently associated with BRD, followed by M. bovis (47.5%, 57/120), BVDV (42.5%, 51/120), BoHV-1 (28.3%, 34/120), BRSV (24.2%, 29/120), and BPIV-3 (8.3%, 10/120). Additionally, antigens of BVDV, MCFV, and M. bovis were the most frequently identified agents associated with singular and concomitant infections. The MCFV identified during this study is more likely to be ovine gammaherpesvirus 2 (OvHV-2), since OvHV-2 is the only MCFV identified within the geographical region of this study. Interstitial pneumonia with proliferative vascular lesions may be a useful histologic feature to differentiate MCFV-induced pneumonia from other viral pneumonias of cattle. These results demonstrate that MCFV and M. bovis, in single or mixed infections, can produce pneumonia in cattle and should therefore be considered as primary agents in the development of BRD.

Soluble guanylate cyclase stimulator reduced the gastrointestinal fibrosis in bleomycin-induced mouse model of systemic sclerosis

BackgroundSystemic sclerosis (SSc) is a chronic autoimmune-mediated connective tissue disorder. Although the etiology of the disease remains undetermined, SSc is characterized by fibrosis and proliferative vascular lesions of the skin and internal organs. SSc involves the gastrointestinal tract in more than 90 % of patients. Soluble guanylate cyclase (sGC) stimulator is used to treat pulmonary artery hypertension (PAH) and has been shown to inhibit experimental skin fibrosis.MethodsFemale C57BL/6J mice were treated with BLM or normal saline by subcutaneous implantation of osmotic minipump. These mice were sacrificed on day 28 or day 42. Gastrointestinal pathologies were examined by Masson Trichrome staining. The expression of fibrosis-related genes in gastrointestinal tract was analyzed by real-time PCR, and the levels of collagen in the tissue were measured by Sircol collagen assay. To evaluate peristaltic movement, the small intestinal transport (ITR%) was calculated as [dyeing distance × (duodenum − appendix)] − 1 × 100 (%). We treated BLM-treated mice with sGC stimulator or DMSO orally and analyzed them on day 42.ResultsHistological examination revealed that fibrosis from lamina propria to muscularis mucosa in the esophagus was significantly increased in BLM-treated mice, suggesting that BLM induces esophageal hyperproliferative and prefibrotic response in C57BL/6J mice. In addition, the gene expression levels of Col3a1, CCN2, MMP-2, MMP-9, TIMP-1, and TIMP-2 in the esophagus were significantly increased in BLM-treated mice. More severe hyperproliferative and prefibrotic response was observed in the mice sacrificed on day 42 than the mice sacrificed on day 28. The ITR% was found to be significantly lower in BLM-treated mice, suggesting that gastrointestinal peristaltic movement was reduced in BLM-treated mice. Furthermore, we demonstrated that sGC stimulator treatment significantly reduced hyperproliferative and prefibrotic response of esophagus and intestine in BLM-treated mice, by histological examination and Sircol collagen assay.ConclusionsThese findings suggest that BLM induces gastrointestinal hyperproliferative and prefibrotic response in C57BL/6J mice, and treatment with sGC stimulator improves the BLM-induced gastrointestinal lesion.

Sensitivity and specificity of D2-40 in differentiating Kaposi sarcoma from its mimickers

Background Kaposi sarcoma (KS) is a low-grade malignant vascular neoplasm, whose etiology is associated with human herpes virus 8 (HHV8). Owing to its broad clinicopathological spectrum, KS mimics a variety of non-KS vascular lesions both clinically and histologically, thus posing a diagnostic challenge. Immunohistochemical markers are needed to confirm diagnosis. Objective To study the sensitivity and specificity of D2-40 in comparison with HHV8-latent nuclear antigen 1 to identify KS among other cutaneous vascular proliferative lesions. Patients and methods The present study was carried out on 50 cases with cutaneous vascular proliferation. Examination of hematoxylin and eosin-stained sections was done for all cases to verify the diagnosis. Additional sections of all cases were subjected to immunohistochemical stains for the following primary antibodies: HHV8 and D2-40 monoclonal antibody. Results The study included 19 KS cases and 31 non-KS. Among KS lesions 15.8% were patch stage, 26.3% plaque stage, 36.84% nodular stage, 10.5% pyogenic granuloma-like KS, and 10.5% intravascular KS. All KS cases stained positive for HHV8-latent nuclear antigen 1, whereas none of other vascular lesions showed positive staining. Immunohistochemistry using D2-40 showed positive staining in 70% (n=35) and negative staining in 30% (n=15) of the total cases. All KS lesions expressed D2-40 in both endothelial lining and spindle cells. A total of 16 cases of non-KS vascular lesions expressed D2-40 in endothelial lining only. D2-40 positivity of both endothelial lining and spindle cells was found to be equally sensitive and specific to HHV8 for diagnosis of KS. Conclusion D2-40 positivity of both vascular lining and spindle cells can be considered both sensitive and specific stain to differentiate KS from other vascular lesions.

Nasal hemangioma as a cause of epistaxis: a case report

<p class="abstract">Hemangioma is a benign, rapidly growing solitary lesion that usually occurs in the skin and mucous membrane. The exact etiology of such a lesion is unknown, but thought to be due to trauma and hormonal factors. Sinonasal hemangiomas are rare. Bleeding and nasal obstruction with mass sometimes filling the nasal cavity are the usual clinical presentation of such a lesion. We report a case of 42-year-old female with right nasal hemangioma presented with on and off epistaxis and progressive right-sided nasal obstruction. Examination of nasal cavity physically combined with endoscopy revealed a polypoid, reddish colored mass in the nasal cavity on the right side arising from septum. Endoscopic subperichondrfial excision was done under local anaesthesia. The histopathology showed vascular proliferative lesion, consistent with hemangioma. Endoscopic excision is preferred as it helps in better visualization. Subperichondrial excision helps to reduce bleeding also, prevent the recurrence. Although rare, the diagnosis of hemangioma must always be kept in mind while discussing the differential diagnosis of a bleeding mass in the nasal cavity.</p>

No BRAF V600E Mutation Identified in 28 Periocular Pyogenic Granuloma.

BRAF V600E mutations were recently identified in some pyogenic granulomas of skin, particularly lesions arising in patients with port wine stains. In this study, the authors analyzed BRAF gene status in 28 periocular pyogenic granulomas to determine its role in their pathogenesis. Retrospective review of ophthalmic pathology archives from 2007 to 2016 was used to identify pyogenic granulomas of the conjunctiva, eyelid, and orbit. Three eyelid nevi were also analyzed as positive controls. BRAF V600E status was assessed by pyrosequencing of DNA extracted from excess formalin-fixed, paraffin-embedded surgical material. Microscopic examination of the periocular pyogenic granuloma specimens revealed proliferative vascular lesions, with radiating capillary channels surrounded by variable degrees of acute and chronic inflammation. Sequencing did not identify a BRAF V600E mutation in any of the 28 sporadic pyogenic granulomas, including 13 on the eyelid. In contrast, mutation analyses performed in parallel in melanocytic nevi of the eyelid identified BRAF V600E alterations in all 3 cases. The lack of BRAF V600E mutations in 28 sporadic pyogenic granulomas of the conjunctiva and eyelid suggests that such alterations are not a common driver in the pathogenesis of these periocular vascular lesions.

Lesiones Proliferativas Vasculares Cerebrales

Introducción: Las malformaciones vasculares cerebrales, tienen una incidencia del 6%, y son clasificadas de múltiples formas según topografía, morfología, y/o demografía. Con respecto a esta ultima división, dichas malformaciones se pueden clasificar en malformaciones de tipo no proliferativas o proliferativas. Las lesiones proliferativas se dividen en: Moya-Moya (M-M), angiopatia proliferativa cerebral (ACP), y hemangiomas.Materiales y Métodos: En primer lugar se presenta un caso clínico de un paciente que fue asistido en el Centro Endovascular Neurológico, donde se estudió y realizó el diagnostico de lesión proliferativa vascular, operándose para tratamiento de hemorragia intraventricular con hidrocefalia. A partir de este caso clínico ilustrativo se realizó una puesta al día sobre esta patología. Discusión: A La APC es una malformación rara, con una frecuencia del 3,4%, y el M-M tiene una incidencia mayor en Japón (3:100,000). Ambos tienen mayor frecuencia en el sexo femenino, pero la APC se presenta habitualmente a los 22 anos, mientras que el M-M tiene dos picos de presentación: uno a los 5 y otro a los 40 anos. Habitualmente este tipo de lesiones proliferativas se presentan clínicamente como accidentes cerebro vasculares (ACV) de causa isquémica. El estudio gold estándar para el diagnostico de estas malformaciones es la angiografía cerebral. Las APC son malformaciones de gran tamaño pudiendo ocupar un lóbulo o hemisferio entero, con innumerables vasos que se extienden entre neuronas y sustancia blanca normal. En la mayoría de los casos el tratamiento está dirigido para mejorar la hipoperfusión circulatoria con el fin de prevenir nuevos eventos isquémicos. Conclusión: Es importante poder diagnosticar este tipo de lesiones a tiempo, así como diferenciar la angiopatía proliferativa o Moya moya, de otro tipos de malformaciones, ya que tiene implicancias en el tratamiento y pronostico.

Splenic hamartoma with bizarre stromal cells: a case report and literature review

BackgroundSplenic hamartoma is a rare benign vascular proliferative lesion composed of unorganized sinusoid-like channels lined with plump or flat endothelial cells and characterized by a CD8-positive immunophenotype of the lining cells. Scattered bizarre stromal cells can be found in some splenic hamartomas. The presence of splenic hamartoma with bizarre stromal cells is extremely rare and these bizarre cells make it possible to be regarded as a malignancy. Recognition of this rare histologic variant will help to avoid diagnostic confusion and overtreatment of this benign entity.Case presentationWe report a case of a 40-year-old man with occasional left-sided waist back pain. A splenic space-occupying lesion was detected by ultrasound and magnetic resonance imaging. Microscopically bizarre large cells were scattered throughout the splenic hamartoma. The cells exhibited atypical nuclei, scarcely visible cytoplasm, and vesicular chromatin, and they did not form expansile clusters and lacked mitotic activity. An immunohistochemical panel was performed. The bizarre cells strongly expressed vimentin, and the Ki-67 index was very low. The lesion was diagnosed as a splenic hamartoma with bizarre stromal cells.ConclusionsTo the best of our knowledge, this is the first systematic review on a splenic hamartoma with bizarre stromal cells; only six cases have been described in the literature. Proper identification is important to secure adequate treatment.

Laparoscopic splenectomy for sclerosing angiomatoid nodular transformation of the spleen

Sclerosing angiomatoid nodular transformation (SANT) is a rare, benign, proliferative vascular lesion that arises from the splenic red pulp. Most patients with SANT have no clinical symptoms and are discovered incidentally on imaging. There are no definitive radiological signs and a distinction from other splenic diseases, and malignant processes remain difficult. Confirmation of the diagnosis of SANT requires a histological and immunohistochemical evaluation of the resected spleen. Here, we report an unusual case of SANT of the spleen successfully treated with an elective laparoscopic splenectomy (LS). LS is a safe and effective method for diagnosis of SANT.

Role for Runt-related Transcription Factor 2 in Proliferative and Calcified Vascular Lesions in Pulmonary Arterial Hypertension.

Pulmonary arterial hypertension (PAH) is characterized by excessive proliferation of pulmonary artery smooth muscle cells (PASMCs). This is sustained in time by the down-regulation of microRNA (miR)-204. In systemic vascular diseases, reduced miR-204 expression promotes vascular biomineralization by augmenting the expression of the transcription factor Runt-related transcription factor 2 (RUNX2). Implication of RUNX2 in PAH-related vascular remodeling and presence of calcified lesions in PAH remain unexplored. We hypothesized that RUNX2 is up-regulated in lungs of patients with PAH, contributing to vascular remodeling and calcium-related biomineralization. We harvested human lung tissues in which we assessed calcification lesions and RUNX2 expression. We also isolated PASMCs from these tissues for in vitro analyses. Using a bidirectional approach, we investigated the role for RUNX2 in cell proliferation, apoptosis, and calcification capacity. Ectopic delivery of small interfering RNA against RUNX2 was used in an animal model of PAH to evaluate the therapeutic potential of RUNX2 inhibition in this disease. Patients with PAH display features of calcified lesions within the distal pulmonary arteries (PAs). We show that RUNX2 is up-regulated in lungs, distal PAs, and primary cultured human PASMCs isolated from PAH and compared with patients without PAH. RUNX2 expression histologically correlates with vascular remodeling and calcification. Using in vitro gain- and loss-of-function approaches, we mechanistically demonstrate that miR-204 diminution promotes RUNX2 up-regulation and that sustained RUNX2 expression activates hypoxia-inducible factor-1α, leading to aberrant proliferation, resistance to apoptosis, and subsequent transdifferentiation of PAH-PASMCs into osteoblast-like cells. In the PAH Sugen/hypoxia rat model, molecular RUNX2 inhibition reduces PA remodeling and prevents calcification, thus improving pulmonary hemodynamic parameters and right ventricular function. RUNX2 plays a pivotal role in the pathogenesis of PAH, contributing to the development of proliferative and calcified PA lesions. Inhibition of RUNX2 may therefore represent an attractive therapeutic strategy for PAH.

Progression of Serosal Vascular Proliferative Lesions to Hemangiosarcomas in the Uterus of the 26-Week Tg.rasH2 Mice Carcinogenicity Studies.

Tg.rasH2 mice are predisposed to hemangiosarcomas. Following the spleen, the uterus is the second most commonly affected organ in the female mice. Female mice are also predisposed to spontaneous vascular proliferative lesions on the serosal surface of the uterus, in which there is proliferation of normal vessels that are lined by well-differentiated endothelial cells. The hemangiosarcomas and vascular proliferative lesions can occur independently. In our facility, we have recorded a total of 47 uterine hemangiosarcomas in 3,985 female Tg.rasH2 mice assigned to various groups in 38 studies. Of these 47 cases, we have seen 22 (46.8%) cases where there was a clear progression of the serosal uterine vascular proliferative lesion into a hemangiosarcoma. In the remaining 25 (53.2%) cases, the uterine hemangiosarcomas involved myometrium and endometrium, but there was no serosal vascular proliferation. Based on the retrospective analysis of our data, we demonstrate that the vascular proliferative lesions noted on the serosal surfaces can progress to hemangiosarcomas and therefore these vascular proliferative lesions should be considered as preneoplastic lesions.

Abstract 3274: VEGF─receptor antagonist, Sugen 5416, sensitizes pulmonary endothelial stem-like cells to estrogens: A microvascular model for the progression of lung cancer

Abstract Proliferative vascular lesions are an aggressive angiogenic phenotype associated with a poor prognosis in non-small cell lung cancer (NSCLC). Recent studies suggest that CD133+ endothelial stem-like cells are recruited to the angiogenic vascular system of NSCLC; and are associated with tumor stage and progression. Epidemiological studies have reported that women who received hormone replacement therapy (HRT) show an overall lower survival to lung cancer especially NSCLC when compared to women with no HRT. Proliferative vascular lesions have been studied extensively using the VEGF─receptor antagonist, Sugen 5416 (SU5416), plus chronic hypoxia (SuHx) rodent model. Therefore, the aim of this study was to determine whether SU5416 exposure of human pulmonary vascular endothelial cells (ECs) become more sensitive to estrogen-induced cell growth. We exposed human pulmonary endothelial cell line HPMEC-ST1.6R to SU5416 to select for a sub-population of cells which were then treated with 17β-estradiol and/or estrogenic polychlorinated biphenyl 153 (PCB153). We observed a significant increase of 2-3 fold change in cell growth and proliferation as determined by MTT, SRB, BrdU, and FACS analysis when SU5416 treated cells were exposed to estrogenic chemicals. Sugen 5416 treatment of ECs showed an increase in the inhibitor of DNA binding and differentiation protein 3 (ID3) along with stem cell markers CD133, Oct-4, and Sox-2. Immunohistochemistry of lung tissue samples from SuHx rodent model showed increased expression of ID3 in pulmonary vascular lesions that correlated with an increase in stem cell markers Oct-4 and Nanog; and increased VEGFR3+ cells surrounding vessel obliterating lesions from SuHx lung tissue. Our findings demonstrate that SU5416 sensitized cells to estrogens resulting in higher cell growth compared to control. Since VEGFR3 expression levels are reported to correlate with metastasis in NSCLC patients, our findings may be used as a model to study how VEGFR3 signaling can promote the aggressive growth and spread of lung cancer when exposed to estrogenic chemicals. Furthermore, we showed that stem cell markers Oct-4, Sox-2, and Nanog are inducible molecular targets of Sugen 5416 treatment. This finding is significant in that it points toward a potential mechanism of chemical-induced pluripotent stem-like cells. A better understanding of how vascular lesions depend on SU5416 may open new avenues for the prevention and treatment of lung cancer. The presence of stem cell markers does not imply that these cells actually function as stem cells. Instead, we propose that the combination of stem cell marker expression and chemical exposure to Sugen 5416 re-program terminally differentiated ECs to a pluripotent cell that gives rise to a clonal pulmonary vascular lesion that supports the aggressive growth of NSCLC. Citation Format: Mayur Doke, Quentin H. Felty. VEGF─receptor antagonist, Sugen 5416, sensitizes pulmonary endothelial stem-like cells to estrogens: A microvascular model for the progression of lung cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3274.

High prevalence of specific KIR types in patients with HHV-8 positive cutaneous vascular lesions: a possible predisposing factor?

Human herpesvirus 8 (HHV8) has been hypothesized to be a potential cofactor for the development of diverse cutaneous vascular proliferative lesions, including eruptive cherry angiomas. Recent reports evidenced the influence of killer cell immunoglobulin-like receptor (KIR) gene diversity in defining the susceptibility to symptomatic herpesvirus infections. In this study, skin samples from vascular lesions and healthy controls were characterized simultaneously for the presence of HHV8 and for the KIR genotype, focusing upon the presence of the KIR2DL2/DS2 and KIR2DL3 genes, which have been associated to herpesvirus susceptibility. The results showed that about 64% of the vascular lesions resulted positive for the presence of HHV8, whereas no control healthy skin samples harbored HHV8 DNA. HHV8-positive patients had a significantly increased frequency of KIR2DL2/DS2 homozigosity and a concomitant decrease of the homozygous KIR2DL3 genotype, compared to healthy controls or HHV8-negative patients. Notably, the simultaneous presence of KIR2DL2/DS2 homozygosity and HHV8 infection resulted in a significantly increased risk to develop cutaneous lesions (OR 5.7) compared to the individual factors alone, suggesting that specific KIR genotypes might predispose to HHV8 symptomatic infection, allowing the virus to exert its angioproliferative activity at skin level.

Abstract 14631: Pulmonary Artery Calcification: A New Threat in Pulmonary Arterial Hypertension

Background: Pulmonary arterial hypertension (PAH) is associated with imbalance between proliferation and apoptosis of pulmonary artery (PA) smooth muscle cells (PASMCs). Recently, we uncovered a role for microRNA-204 (miR-204), whose downregulation sustains the phenotype in time. In systemic vascular disease, miR-204 downregulation increases the Runt-related transcription factor 2 (RUNX2), a key osteogenic factor inducing calcification. The fact that PAH patients live longer increases the odds of developing PA calcification lesions. Interestingly, the presence and development of calcified lesions in PAH have not been explored. We thus hypothesized that miR-204-dependent upregulation of RUNX2 triggers the development of proliferative and calcified vascular lesions within the lungs, thus worsening PAH. Methods/Results: Using CT-scan, we showed that PAH patients (n=50; p<0.05) had significant increase in distal PA calcification compared to control patients matched for age, sex and comorbidities known to promote vascular calcification. This non-invasive finding was histologically confirmed in the same patients post lung transplantation using Von Kossa staining (n=10; p<0.05). Finally, increase in calcification contributes to worsening of PA compliance and is associated with poorer PAH patients’ survival (n=50; p<0.05). At the molecular level, enhanced calcification in PAH patients correlates (n=43; p<0.05) with a miR-204-dependent up regulation of RUNX2 in lungs, distal PA and primary cultured PASMCs (n=12-40, fold change ≈ 2.5). Using gain and loss of function approaches, we demonstrated in PASMCs from PAH and healthy donors (using siRNA and adenoviruses respectively) that RUNX2, promotes PAH-PASMC proliferation (Ki67), resistance to apoptosis (Annexin-V) and calcification (Alizarin red) (p<0.05). Finally, in Sugen/hypoxia rat model of PAH, we demonstrated that RUNX2 inhibition improves pulmonary hemodynamic and reduces PA remodeling and calcification (n=5-12, p<0.05). Conclusion: We demonstrated for the first time the presence of significant calcification in PAH distal PA contributing to PAH worsening and identified RUNX2 as an attractive new therapeutic strategy to improve PAH. *SC and GR equally contributed.