Search

Copyright of Revista Medica Herediana is the property of Universidad Peruana Cayetano Heredia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Epithelioid angiosarcoma is a rare variant of angiosarcoma characterized by an epithelioid morphology that mimics carcinoma. Therefore, multicentral epithelioid angiosarcoma is easily misdiagnosed as bone metastasis from carcinoma and has an aggressive clinical course. Here, we present a rare case of a 61-year-old male with multicentral epithelioid angiosarcoma of the bone. Plain radiography, CT, and MRI revealed multiple osteolytic lesions in both femurs; some lesions showed soft tissue extension with cortical bone destruction. Interestingly, PET-CT revealed that the lesions were only distributed along the bones of the lower extremities, including the pelvic bones, femurs, and tibiae. Despite histological analysis initially suggesting metastatic carcinoma, after additional immunohistological staining, including that for vascular markers (CD31 and ERG), the final diagnosis was epithelioid angiosarcoma. A better understanding of the clinic radiological features of this disease may help eliminate diagnostic confusion and provide better management. [ABSTRACT FROM AUTHOR]

Retroperitoneal hemangiosarcoma (RPHSA) is a rare tumor in dogs with a poorly understood prognosis after surgery. The objectives of this study were to investigate the clinical features and prognosis of canine RPHSA that had undergone surgical resection. In this single-center, retrospective cohort study, we reviewed the medical records of dogs that had undergone surgical resection for retroperitoneal tumors and received a histopathologic diagnosis of HSA between 2005 and 2021. The median progression-free survival (PFS) and overall survival (OS) were 77.5 days and 168 days, respectively. In the present study, canine RPHSA had an aggressive biological behavior similar to visceral HSA. Further studies in larger canine populations are needed to evaluate the efficacy of adjuvant chemotherapy. [ABSTRACT FROM AUTHOR]

Case series summary: Nasal planum tumors are rare in cats, with squamous cell carcinoma over-represented. Other skin tumors have been reported in this location and though hemangiosarcoma frequently occurs on the skin of the head, these tumors localized to the nasal planum have not been specifically reported. The objectives of this study were to report the clinical findings and outcomes in cats diagnosed with hemangiosarcoma of the nasal planum. Medical records from four different institutions were reviewed to identify cats with a definitive diagnosis of hemangiosarcoma of the nasal planum. Five cats met the inclusion criteria. One cat was treated with palliative radiation therapy (RT) alone, two cats had lesions removed via an excisional biopsy by the primary care veterinarian and two cats had excisional biopsies performed at a referral institution. All four cats that received surgical treatment were treated with adjuvant strontium-90 therapy. The cat receiving palliative RT alone was lost to follow-up 311 days after treatment. At the time of writing, the survival time for 2/3 cats receiving surgery and strontium-90 was 365 days and 1381 days, respectively. One cat receiving this combination of therapy was lost to follow-up immediately after treatment. One cat developed tumor recurrence and a revision surgery via nasal planectomy and upper lip resection was performed 376 days following the initial surgery. Following revision, palliative RT was pursued. The cat was still alive at the time of writing 618 days after the initial procedure, with no evidence of recurrence. Relevance and novel information: In this case series, surgery was the primary treatment used, but due to the location, only narrow or incomplete surgical margins were possible. RT (strontium-90 and/or palliative) was utilized to decrease the risk of recurrence. [ABSTRACT FROM AUTHOR]

Peroxiredoxin (PRDX) is an antioxidant enzyme family with six isoforms (PRDX1-6). The main function of PRDXs is to decrease cellular oxidative stress by reducing reactive oxygen species, such as hydrogen peroxide, to H2O. Recently, it has been reported that PRDXs are overexpressed in various malignant tumors in humans, and are involved in the development, proliferation, and metastasis of tumors. However, studies on the expression of PRDXs in tumors of animals are limited. Therefore, in the present study, we immunohistochemically investigated the expression of PRDX1 and 2 in spontaneous canine hemangiosarcoma (HSA) and hemangioma (HA), as well as in selected normal tissue and granulation tissue, including newly formed blood vessels. Although there were some exceptions, immunolocalization of PRDX1 and 2 in normal canine tissues was similar to those in humans, rats, or mice. In granulation tissue, angiogenic endothelial cells were strongly positive for PRDX1 and 2, whereas quiescent endothelial cells in mature vessels were negative. Both PRDX1 and 2 were significantly highly expressed in HSA compared to HA. There were no significant differences in the expression of PRDX1 and 2 among the subtypes and primary sites of HSA. These results suggest that PRDX1 and 2 may be involved in the angiogenic phenotypes of endothelial cells in granulation tissue as well as in the behavior in the malignant endothelial tumors. [ABSTRACT FROM AUTHOR]

An 11-year-old male Miniature Dachshund was referred for acute neurological deficits in the pelvic limbs. T2-weighted magnetic resonance imaging revealed that the spinal cord at the L1-2 intervertebral disc space was heterogeneously hyperintense in the sagittal plane and was mildly compressed from the ventral side by a small hypointense mass in the transverse plane. However, the lesion showed mass enhancement and severe spinal cord compression on post-contrast T1-weighted imaging. On three-dimensional myelography, a “golf tee sign” was observed around the mass. Therefore, we diagnosed an intradural extramedullary lesion. The mass was surgically removed and histologically diagnosed as a hemangiosarcoma. The “golf tee sign” observed on magnetic resonance myelography may be useful for distinguishing intradural extramedullary masses from intramedullary masses. [ABSTRACT FROM AUTHOR]

• Photodynamic Therapy was investigated to treat hemangiosarcoma in dogs. • Seven out of eight cases showed complete remission of cutaneous hemangiosarcoma. • Focal PDT did not cause alteration in blood counts or liver and kidney function. • Besides local inflammation and necrosis no side effects were observed. • There was no tumor recurrence in the patients for at least 1.5 years post-treatment. Cutaneous hemangiosarcoma is a malignant neoplasia that frequently occurs in dogs. The most effective treatment requires wide surgical excision of the tumor. To avoid mutilating surgeries, photodynamic therapy (PDT) could serve as an alternative treatment. This study aimed to treat cutaneous hemangiosarcomas in dogs using PDT with aluminium-chloride-phthalocyanine nanoemulsion (AlClPc-nano) as photosensitizer. Eight dogs with histopathological diagnosis of naturally occurring cutaneous hemangiosarcoma were treated. Animals were given intra and peritumoral injections of AlClPc-nano (13.3 μM). After 15 min, the masses were LED irradiated at a wavelength of 658–662 nm (80 mW potency) for 25 min (120 J/cm2 fluency). The number of sessions was based on lesion observations, with PDT sessions repeated every 7 days until the mass was no longer macroscopically visible. On that occasion, an excisional biopsy of the area was taken for histopathology analysis. Blood was collected from each animal before each PDT session and excisional biopsy for hematological analysis (blood counts; liver and kidney function). The number of PDT sessions varied from 2 to 4, depending on the size of the initial mass. Seven of the eight cases demonstrated complete remission of neoplasia. Microscopic analysis of the excisional biopsies showed necrosis and hemorrhage only, with no cancer cells, except in one case. During the treatment, inflammation and necrosis were macroscopically observed in the treated areas. The dogs did not show any alteration in blood parameters that could be related to the PDT. In conclusion, PDT with AlClPc-nano is a safe and effective treatment for cutaneous hemangiosarcoma in dogs. [ABSTRACT FROM AUTHOR]

Copyright of Biomédica: Revista del Instituto Nacional de Salud is the property of Instituto Nacional de Salud of Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Pesquisa Veterinaria Brasileira is the property of Colegio Brasileiro de Patologia Animal - CBPA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hemangiosarcoma is an uncommon tumor in horses. We characterized 3 cases of equine renal hemangiosarcoma, focusing on clinical and pathologic features, and describe occurrence of the epithelioid variant of hemangiosarcoma in one of these cases. Nuclear expression of phosphorylated STAT3 (pSTAT3) was assessed to analyze potential inappropriate STAT3 activation as a component of tumor pathogenesis. Clinical signs in the 3 horses included insidious weight loss, followed in one case by serosanguineous nasal discharge and terminal epistaxis, and nonspecific signs of abdominal pain. Two of the hemangiosarcomas had a classical histopathologic appearance; in the other, neoplastic cells were polygonal and were arranged in densely packed sheets, resembling the epithelioid variant. Cross-reactivity of a pSTAT3 antibody was established by demonstration of pSTAT3 expression in the epithelium of glabrous skin by immunoblotting and immunohistochemistry. In the epithelioid hemangiosarcoma, ~40% of neoplastic cells exhibited nuclear pSTAT3 expression, but in the other 2 cases, expression was weak and variable in the neoplastic population, although stromal cell pSTAT3 activity was evident in pulmonary metastases in one case. [ABSTRACT FROM AUTHOR]

A 12-year-old, spayed female Schnauzer presented with constipation. A mass was observed in the pelvic cavity, and metastasis was not identified. Mass resection was performed through celiotomy with pubic osteotomy, and hemangiosarcoma was diagnosed. At 10 weeks post-operatively, the patient died of multiple metastasis. Primary intrapelvic hemangiosarcoma is rare in dogs. [ABSTRACT FROM AUTHOR]

• Clinical presentation and laboratorial findings are nonspecific in this type of neoplasia in horses. • Disseminated hemangiosarcoma was diagnosticated by histopathology An 8-year-old mare mule was presented with a facial mass and history of anorexia, unilateral epistaxis and purulent nasal discharge. The facial mass was encountered from the ventral to the lateral right canthus of the eye up to the facial crest. Thoracic ultrasonography showed five rounded masses. A standing CT under sedation was performed revealing a huge extension and infiltration on surrounding tissues. Due to the extension, type of lesions, outcome and suspicion of metastasis, the owner chose to euthanize the patient. Necropsy confirmed the presence of tumoral lesions spread into the lungs, spleen, adrenal glands, ovary, oral cavity, and right frontal sinus. The microscopic examination was consistent with hemangiosarcoma. Hence, hemangiosarcoma is a differential diagnosis to rule out in future similar cases. This clinical description did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. [ABSTRACT FROM AUTHOR]

This report describes the usefulness of positron emission tomography-computed tomography (PET-CT) for evaluating recurrent or residual tumors following surgery. CT and 18F-fluorodeoxyglucose PET-CT were pre- and post-operatively applied to multiple masses in a dog with hemangiosarcoma. The distinction between the left subcutaneous mass and the peritoneum was clarified on pre-operative CT examination, and malignancy was suspected based on PET-CT. A recurrent or residual tumor in the left subcutaneous region was suspected on post-operative PET-CT, and confirmed through histopathologic examination. [ABSTRACT FROM AUTHOR]

Copyright of Archivos de Medicina Veterinaria is the property of Universidad Austral de Chile, Facultad de Ciencias Veterinarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista de la Asociación Colombiana de Dermatología y Cirugía Dermatológica is the property of Asociacion Colombiana de Dermatologia y Cirugia Dermatologica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An 18-month-old female guinea pig ( Cavia porcellus ) was presented with a 2-week history of inappetance. A 4 cm abdominal mass was palpated on physical examination. Radiographs were not able to identify the origin of the mass and an exploratory laparotomy was performed. The mass was found to be splenic in origin, occupying approximately 80% of the organ, and the spleen was removed. Histological examination and immunohistochemistry confirmed the mass to be consistent with a splenic hemangiosarcoma. Further examination of the abdominal cavity and thoracic radiographs of the guinea pig revealed no evidence of metastatic disease. Postsurgical survival was 17 months, with no radiographic evidence of tumor recurrence or metastases during that time. Spontaneous splenic hemangiosarcoma is rare in this species, but should be considered as a differential for an abdominal mass. [ABSTRACT FROM AUTHOR]

A 13-yr-old intact male cheetah ( Acinonyx jubatus) presented for evaluation after a 4-mo history of intermittent lethargy and increased expiratory effort. The clinical signs were initially noted after the diagnosis and death of its 13-yr-old male sibling with solitary hepatic T-cell lymphoma. Physical examination findings included thin body condition, harsh lung sounds, peripheral lymphadenopathy, and a cutaneous mass on the right medial tarsus and scrotum. Excisional biopsies diagnosed well-differentiated cutaneous hemangiosarcomas. Thoracic radiographs revealed a cranial mediastinal mass. Complete blood count and serum biochemical analyses showed a leukocytosis with persistent lymphocytosis, progressive azotemia, and markedly elevated alkaline phosphatase. Because of the cheetah's declining quality of life, euthanasia was elected. Postmortem examination, histopathology, and immunohistochemical staining revealed multicentric T-cell lymphoma. Feline leukemia virus (FeLV) enzyme-linked immunosorbent assay, FeLV polymerase chain reaction (whole blood), and viral metagenomic analysis were negative. This is the first case of cutaneous hemangiosarcoma and multicentric T-cell lymphoma reported in a FeLV-negative cheetah. [ABSTRACT FROM AUTHOR]

Dynamic left ventricular outflow tract obstruction (DLVOTO) is a common condition in cats and humans. In this case report, a dog is described with DLVOTO secondary to severe intra-abdominal hemorrhage caused by a hemangiosarcoma. The dog was a 9-year-old, 35.7-kg, spayed female German Shepard dog that presented with a history of tachypnea and collapse. A Levine II/VI systolic murmur was present at the heart base. Abdominal ultrasonography revealed a splenic mass and a large amount of ascites. Echocardiography showed a reduced left ventricular diameter and an increased aortic velocity caused by systolic anterior motion (SAM) of the mitral valve apparatus. The heart murmur and the SAM were resolved after treatment including a splenectomy and a blood transfusion. [ABSTRACT FROM AUTHOR]

Abstract: A second parity, 1-year-old female Norway rat (Rattus norvegicus) presented for veterinary evaluation 5 weeks postpartum with a progressively decreased appetite, weight loss, lethargy, and labored breathing. On physical examination, the animal was in fair body condition, dyspneic, and dehydrated. Owing to a poor prognosis, the owner opted for palliative care for the animal, declined further diagnostic testing, and requested for the rat to be discharged from the hospital. The following day the animal was found dead in its cage, and the body was submitted for necropsy. Gross observations included numerous, variably sized, soft, dark red pulmonary nodules concurrent with hemothorax and hemopericardium. Microscopically, the pulmonary architecture was effaced by nodules of variably sized, irregular, vascular channels lined with neoplastic endothelial cells. The cytoplasm of neoplastic cells in the lung was immunohistochemically positive for von Willebrand factor (i.e., factor VIII–related antigen) and was more intensively and more often positive for vascular endothelial growth factor as compared with nonneoplastic cells. Ultrastructurally, vascular channels were formed by spindloid neoplastic cells with elongated, fused, and interdigitated processes. Based on these findings, a diagnosis of spontaneous pulmonary hemangiosarcoma was made in this Norway rat. [Copyright &y& Elsevier]

The article highlights the effectiveness of using serum ferritin measurement as a tumor marker in dogs with splenic masses. Topics discussed include the epidemiology of hemangiosarcoma (HSA), the association between serum ferritin concentration and plasma ALT activity as an indicator of hepatocyte injury, and the probable causes of hyperferritinemia in dogs with HSA. The clinical usefulness of hyperferritinemia as a sensitive test in dogs with splenic masses is also mentioned.

Hemangiosarcomas are uncommon aggressive vascular tumors that have recently become the focus of attention because several chemicals and pharmaceuticals increase their incidence in mice. The relevance of these mouse vascular tumors to humans is unclear. In the present study, we semiquantitatively evaluated the expression profiles of hematopoietic stem cell markers (CD117 [c-kit], CD133, CD34, and CD45), endothelial cell markers (vascular endothelial growth factor receptor 2, CD31, and factor VIII-related antigen), and a myeloid lineage cell marker (CD14) in human hemangiosarcoma (n = 12) and hemangioma (n = 10) specimens using immunohistochemistry. CD133 was completely negative in almost all cases of hemangiosarcomas and hemangiomas. Most hemangiosarcomas, but not hemangiomas, stained for CD117 and CD45. Both groups diffusely expressed CD34, vascular endothelial growth factor receptor 2, and factor VIII-related antigen; however, hemangiomas had more intense and diffuse CD34 and factor VIII-related antigen expression compared with hemangiosarcomas, whereas CD31 was positive in all hemangiosarcomas but only half of the hemangiomas. CD14 staining was negative in most hemangiosarcoma and hemangioma cases. Our results indicate that multipotential bone marrow-derived hematopoietic stem cells or early endothelial progenitor cells (EPCs) expressing CD117, CD34, and CD45 are involved in hemangiosarcoma formation, whereas hemangiomas originate from late EPCs or differentiated endothelial cells, which have lost the expression of most hematopoietic stem cell markers. This contrasts with our previous results that demonstrated that both hemangiosarcomas and hemangiomas in mice may be derived from early EPCs that are not completely differentiated. [ABSTRACT FROM AUTHOR]

The article describes the clinical and pathological findings of a three-year-old Pinscher dog that was presented with multifocal neurologic signals because of multicentric hemangiosarcoma (HSA). It defines HSA as a highly malignant neoplasm of vascular endothelial origin occurring more frequently in dogs. In the case, the dog was referred to the Neurological and Neurosurgical Service of Veterinary Teaching Hospital due to lameness and pain in its hind limbs.

Hemorrhagic splenic masses diagnosed as hemangioma or hemangiosarcoma were reviewed. Lymphoid hyperplasia was present in none of the hemangiosarcoma cases and in 27% of the hematoma cases. Siderotic nodules in the capsule or trabeculae were present in 25% of hemangiosarcoma cases and in 36% of hematoma cases. Hemoabdomen was noted in the clinical history of 54% of hemangiosarcoma cases and in 22% of hematoma cases. The average age (10.3 and 9.6 years, respectively), sex ratios (slightly more males), and most common breeds (Labrador Retriever, Golden Retriever, and German Shepherd Dog) were similar for the hemangiosarcoma and hematoma cases. Since lymphoid hyperplasia is much more common in cases of hematoma, the presence of this feature lends support to a diagnosis of hematoma rather than hemangiosarcoma. Signalment, history of hemoabdomen, and presence of siderotic nodules do not point to one diagnosis over the other. [ABSTRACT FROM PUBLISHER]

The article discusses the clinical case of a five-year-old Java sparrow (Padda oryzivora) for hemangiosarcoma with widespread metastasis. Histopathological examination on the bird's corpse revealed that neoplastic cells proliferated solidly or formed abundant irregular blood vessels. The neoplastyic cells were found positive for anti-human von Willebrand factor antibodies.

The article discusses a study which describes vulvar epithelioid hemangiosarcoma with solar elastosis in a 15-year-old female gray Appaloosa horse. The mare was observed to have a mass over the right dorsal commissure of vulva for seven months before it was presented for examination. Hemangiosarcoma refers to a malignant tumor of vascular endothelial cells, whose origin in unknown in most cases.

The article describes the case of a female grower pig submitted for necrospy. A conventional polymerase chain reaction (PCR) virologic examination showed Porcine reproductive and respiratory syndrome virus in the lung tissue. A neoplastic growth in the leptomeninges of the olfactory bulb with focal invasion of the brain was revealed after histologic examination. It suggests that primary hemangiosarcoma should be considered as a rare differential diagnosis affecting the central nervous system (CNS) of adolescent domestic pigs.

Angiosarcoma is a rare malignant vascular tumor. Pulmonary involvement is usually attributable to metastasis from other primary sites, primary pulmonary angiosarcoma therefore being quite uncommon. We report a case of angiosarcoma with pulmonary involvement, probably primary to the lung, which had gone untreated for more than two years. We describe this rare neoplasm and its growth, as well as the extensive local invasion and hematogenous metastasis at presentation. We also discuss its poor prognosis. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Pulmonology / Jornal Brasileiro de Pneumologia is the property of Sociedade Brasileira de Pneumologia e Tisiologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study demonstrated magnetic resonance imaging (MRI) and computed tomography for large-sized splenic hemangiosarcoma. Radiography and ultrasonography revealed the presence of a large-sized soft-tissue mass in the cranial abdomen. Computed tomography showed hypoattenuating mass. The mass was located in contact with liver, spleen and stomach, and the origin of the mass remained ambiguous. The mass was T2-hyperintense and T1-hypointense with mild contrast enhancement. MRI allowed a differentiation between large-sized tumor and neighboring normal structure, and the mass was consequently identified as arising from spleen. These results suggested that MRI might be a useful tool to visualize large-sized splenic tumors and improve the accuracy of diagnosis. [ABSTRACT FROM AUTHOR]

The article describes the case of a 9-year-old Brazilian Fila male dog that had been affected by a tissular formation of the nictitant membrane of the right eye with four months of evolution. The findings of this case report were consistent with the diagnosis of hemagiosarcoma of the nictitant membrane. They indicate that hemangiosarcoma must be considered on the diagnosis of the neoplasm that affects the eyes and annexa of dogs and that its complete removal prevents relapses.

Abstract: Hedgehogs are susceptible to tumors involving the integumentary system. In this case report, an adult female African hedgehog (Atelerix albiventris) presented to the teaching hospital at Oklahoma State University for a cutaneous mass that appeared after trauma. A histologic diagnosis of epithelioid variant hemangiosarcoma was made on examination of the surgically excised mass. Six months after excision, a second mass appeared in the same location and euthanasia was elected because of the poor prognosis with tumor recurrence. Necropsy examination revealed an extensive subcutaneous mass with histological features similar to the initial surgical biopsy and the presence of distant site metastasis. Immunohistochemistry supported the diagnosis of primary cutaneous epithelioid variant hemangiosarcoma with distant site metastases. [Copyright &y& Elsevier]

Pericardial effusion is a potentially life-threatening problem leading to a rise in the intrapericardial pressure resulting in varying degrees of hemodynamic compromise. Cardiac tamponade occurs when the intrapericardial pressure equals or exceeds right ventricular diastolic filling pressures leading to a decreased cardiac output. In dogs, the most common causes of pericardial effusion that require pericardiocentesis are cardiac neoplasia and idiopathic pericardial effusion (IPE). The incidence of cardiac neoplasia in dogs is low, and it is rare in cats. In dogs, hemangiosarcoma and chemodectoma are the two most common types of cardiac neoplasia. In cats, lymphosarcoma is the most common form of cardiac neoplasia, but they are more likely to develop pericardial effusion secondary to congestive heart failure or feline infectious peritonitis. Common histories include lethargy, dyspnea, anorexia, collapse, and abdominal distension. Pericardiocentesis is used to stabilize animals with life-threatening cardiac tamponade, relieve the pressure leading to right-sided heart failure, and obtain fluid samples for diagnostic evaluation. The fluid should be quantified and characterized. Serious complications associated with pericardiocentesis are rare. Complications include cardiac puncture, arrhythmias, and laceration of a tumor or coronary artery resulting in intrapericardial hemorrhage or sudden death. [Copyright &y& Elsevier]

Angiosarcoma is a malignancy that occurs rarely in the gastrointestinal tract. We present a case of a 77-year-old male who had rectal bleeding and obstructive bowel symptoms. A large near-obstructing mass was seen endoscopically, but biopsies were inconclusive. A CT scan showed a large sigmoid lesion, and the patient had surgical resection. A large hemorrhagic-appearing tumor was found at operation. Angiosarcoma of the sigmoid colon was diagnosed on histologic examination. After colonic resection, the patient rapidly developed numerous liver metastases and died six months later. A review of the literature reveals only 12 other reported cases of colorectal angiosarcoma; 62 percent of these patients died within one year of surgical resection. The role of adjuvant radiation and/or chemotherapy is unclear. In conclusion, colorectal angiosarcomas are rare tumors that behave very aggressively, and the outcome is generally poor. [ABSTRACT FROM AUTHOR]

Summary: Riddelliine alters hepatocellular and endothelial cell kinetics and function including stimulating an increase in hepatocytic vascular endothelial growth factor (VEGF) in the absence of increased serological levels of VEGF (Nyska etal. 2002). The objective of this study was to further assess hepatic VEGF and KDR/flk-1 synthesis and expression by hepatic cells under riddelliine treatment conditions. Forty-two male F344/N rats were dosed by gavage with riddelliine (0, 1.0, and 2.5 mg/kg/day) for 6 weeks. Seven animals/group were sacrificed after 8 consecutive daily doses; remaining rats were terminated after 30 daily doses, excluding weekends. Hepatic tissues were evaluated by immunohistochemistry and in situ hybridization. The results showed that VEGF mRNA expression was observed in control and treated animals; however, qualitative differences were noted. Treated animals exhibited VEGF mRNA in clustered, focal hepatocytes and bile duct epithelium, whereas VEGF mRNA in hepatocytes from vehicle control rats was distributed evenly across all hepatocytes. Results evaluating the distribution of the VEGF cognate receptor, KDR/flk-1 showed that randomly distributed, rare sinusoidal endothelium, including those demonstrating karyomegaly and cytomegaly expressed KDR/flk-1. Phosphorylation of KDR/flk-1 at pTyr996 and pTyr1054/1059, but not pTyr951, was also detected, evidence that endothelial cell KDR/flk-1 was activated. These results suggest that both hepatocytes and endothelial cells are targets of riddelliine-induced injury. We speculate that damage to both populations of cells may lead to dysregulated VEGF synthesis by hepatocytes and activation of KDR/flk-1 by endothelium leading to the induction of sustained endothelial cell proliferation, culminating in the development of hepatic hemangiosarcoma. [Copyright &y& Elsevier]