Comprehensive Analyses of Coagulation Parameters in Patients with Vascular Anomalies.

BACKGROUND: Vascular anomalies comprise a diverse group of rare diseases with altered blood flow and are often associated with coagulation disorders. The most common example is a localized intravascular coagulopathy in venous malformations leading to elevated D-dimers. In severe cases, this may progress to a disseminated intravascular coagulopathy with subsequent consumption of fibrinogen and thrombocytes predisposing to serious bleeding. A separate coagulopathy is the Kasabach-Merritt phenomenon in kaposiform hemangioendothelioma characterized by platelet trapping leading to thrombocytopenia and eventually consumptive coagulopathy. Our previous work showed impaired von Willebrand factor and platelet aggregometry due to abnormal blood flow, i.e., in ventricular assist devices or extracorporeal membrane oxygenation. With altered blood flow also present in vascular anomalies, we hypothesized that, in particular, the von Willebrand factor parameters and the platelet function may be similarly impacted. METHODS: We prospectively recruited 73 patients with different vascular anomaly entities and analyzed their coagulation parameters. RESULTS: Acquired von Willebrand syndrome was observed in both of our patients with Kasabach-Merritt phenomenon. In six out of nine patients with complex lymphatic anomalies, both the vWF antigen and activity were upregulated. Platelet aggregometry was impaired in both patients with Kasabach-Merritt phenomenon and in seven out of eight patients with an arteriovenous malformation. CONCLUSIONS: The analysis of coagulation parameters in our patients with vascular anomalies advanced our understanding of the underlying pathophysiologies of the observed coagulopathies. This may lead to new treatment options for the, in part, life-threatening bleeding risks in these patients in the future.

Development of Kasabach-Merritt phenomenon following vaccination: More than a coincidence?

Kasabach-Merritt phenomenon (KMP) occurred uniquely in patients with kaposiform hemangioendothelioma (KHE) and tufted angioma (TA). We report the clinical characteristics of two patients with KHE involving the right upper arm. The patients demonstrated rapid enlargement of the lesion with severe KMP shortly after vaccination. Sirolimus was used to treat the KHE with KMP. The patients showed a quick normalization of the platelet level. The follow-up examination revealed that the size of the mass was significantly decreased. This report raises the intriguing possibility that extrinsic factors may contribute to the development of KMP in the context of an already existing KHE.

Resolution of reactive angioendotheliomatosis in an arteriovenous fistula with innominate vein angioplasty.

INTRODUCTION: Arteriovenous fistulae (AVF)-associated reactive angioendotheliomatosis (RAE) is a very rare entity (three previously reported cases in the literature) that can manifest as extremity wounds. RAE's etiopathology is unknown. CASE DESCRIPTION: We report a case of severe limb-threatening upper extremity wound with pathology-proven RAE. This lesion was previously refractory to standard wound care. There was no evidence of limb ischemia or steal syndrome, previously deemed to be the underlying cause of AVF-associated RAE in other reports. CONCLUSIONS: Successful endovascular treatment of an ipsilateral innominate vein stenosis led to reduction of venous hypertension, resolution of associated arm edema, and subsequent wound healing. We therefore propose that venous engorgement and hypertension from central venous stenosis is the likely underlying cause for AVF-associated RAE. If this rare entity is encountered in the setting of AVF, there is utility in treating the wound as a sentinel lesion and venography should be conducted to rule out central venous pathology. Vascular intervention complements aggressive local wound management and biopsy is requisite for prompt diagnosis.

IMAGING DIAGNOSIS-MAGNETIC RESONANCE IMAGING FINDINGS IN A CAT WITH SYSTEMIC REACTIVE ANGIOENDOTHELIOMATOSIS.

A 10-year-old, castrated male domestic short-haired cat was presented with an acute history of seizures, lethargy, anorexia, vomiting, and dyspnea. Magnetic resonance imaging of the brain showed multifocal areas of gray matter T2-weighted hyperintensity. The lesions did not enhance with intravenous contrast. The cat was diagnosed at necropsy with feline systemic reactive angioendotheliomatosis, a rare vascular proliferative disorder for which a treatment has not yet been identified. This report is the first to describe associated magnetic resonance imaging changes for this disease.

Pseudomyogenic hemangioendothelioma secondary to fibrous dysplasia of the left lower extremity in a 14-year-old female: a case report.

BACKGROUND: Pseudomyogenic hemangioendothelioma is a rare soft tissue tumor usually found in young adults, predominantly males. Fibrous dysplasia is a common benign bone tumor, which accounts for 5~7 % of all the primary benign bone tumors. However, pseudomyogenic hemangioendothelioma secondary to fibrous dysplasia is extremely rare. To the best of our knowledge, this is the first case of pseudomyogenic hemangioendothelioma secondary to fibrous dysplasia. CASE PRESENTATION: This study describes a case of a 14-year-old female who suffered from pseudomyogenic hemangioendothelioma secondary to fibrous dysplasia of the left lower extremity. The patient underwent two operations successively due to pathological fractures in the left femur and tibia in a local hospital. She was diagnosed with fibrous dysplasia according to the postoperative pathological examinations. However, less than 1 year later, she was diagnosed with a recurrence of fibrous dysplasia in her left femur during a follow-up in our hospital. She underwent a curettage and grafting in the left femur. Postoperative pathological examinations demonstrated the diagnosis of fibrous dysplasia. Nevertheless, she presented to our clinic with a chief complaint of pain and swelling in her left tibia and calcaneus 4 months later. The patient underwent fine-needle aspiration in her left tibia. According to the histological and immunohistochemical findings, the diagnosis of pseudomyogenic hemangioendothelioma was confirmed by an expert pathology consultant. Finally, the patient had to undergo an amputation of the left thigh. Postoperative pathological examinations confirmed the diagnosis of pseudomyogenic hemangioendothelioma. Postoperative follow-up at 3 months disclosed no evidence of recurrent disease and no residual side effects from therapy. CONCLUSIONS: Pseudomyogenic hemangioendothelioma is a rare endothelial neoplasm which often mimics myoid and epithelioid tumors morphologically. For the diagnosis, the immunostaining is very important but not decisive and enough. Analysis based on any single factor or incomplete information may easily lead to arbitrary conclusion. Clinical information including age, gender, tumor location, disease course, and recurrence is important for appropriate diagnosis, and full understanding of the tumor is indispensable.

Thalassemia major between liver and heart: Where we are now.

The aim of the study was to assess the current state in terms of liver and heart iron overload as well as of liver and heart related morbidity and mortality in a large cohort of thalassemia patients. Myocardial iron loading was present in 28.9% patients, which was severe in 3.2%. Liver iron was normal in 9.3% and severe in 15%. The rate of cardiac deaths started to decrease between 2000 and 2003 and dropped significantly afterwards. The prescription of combination therapy soon after the hospital admission for decompensated heart failure was associated with a decrease in the short-term mortality. In 111 adult patients who underwent liver elastometry, 14 HCVRNA positive subjects and 2 HCVRNA negative, had stiffness values suggestive of cirrhosis. No cases of hepatocarcinoma were reported. Liver "iron free foci" occurred in a HCV negative patient and the occurrence of a malignant epithelioid hemangioendothelioma led to liver transplantation in another. The study suggests that a subset of patients continues to develop progressive hemosiderosis that may lead to cardiac disease and death. Beyond its key role in preventing myocardial iron overload, liver iron chelation is essential for hampering the onset of hepatic tumors, which may not be limited to hepatocarcinoma.

Medical management of tumors associated with Kasabach-Merritt phenomenon: an expert survey.

Kasabach-Merritt phenomenon (KMP) is a rare consumptive coagulopathy characterized by profound thrombocytopenia and hypofibrinogenemia occurring in association with the vascular tumors kaposiform hemangioendothelioma (KHE) and tufted angioma (TA). Treatment remains challenging without consensus on the optimal medical management. The authors compiled expert opinions regarding management to establish treatment recommendations. Twenty-seven vascular anomalies centers in the United States and Canada were surveyed using 2 representative cases of KHE/TA with and without KMP. Overall response rate was 92% (25/27) with 88% completion (24/27). Most sites (23/25; 92%) do not have a standard of practice for management. The most frequent initial therapy for KHE+KMP was a combination of systemic corticosteroids and vincristine (VCR) (12/24 centers; 50%) followed by corticosteroids alone (29%). Second-line treatments were VCR (38%), rapamycin (21%), and propranolol (21%). Management of KHE/TA without KMP was variable; initial treatments included systemic corticosteroids (8/24; 33%) alone or with VCR (9/24; 38%), monitoring without medication (33%), VCR (8%), propranolol (8%), aspirin (4%), and rapamycin (4%). This survey highlights certain trends in the management of KMP-associated tumors, without standard protocols and consensus.

Hepatic haemangioendothelioma: a vertical association with biliary atresia?

Haemangioendotheliomas (HAE) are the commonest vascular tumours of the liver in infancy and are characterised by solitary or multifocal lesions often arising in conjunction with cutaneous haemangiomas. The authors report on a 4-month-old infant with massive hepatomegaly and hypothyroidism due to multifocal HAE whose mother had been born with biliary atresia. As the incidence of biliary atresia in the UK is about 1 in 16 000 live births, the association reported here seems more than co-incidental. This report reviews the literature and discusses potential aetiologies to explain this rare association.

Polymorphous hemangioendothelioma in a child with acquired immunodeficiency syndrome (AIDS).

Polymorphous hemangioendotheliomas (PH) are rare and borderline malignant tumors that are among the wide range of vascular tumors. We report here a 13-year-old male presenting with a history of weight loss, opportunistic infections, and lymphadenopathy. He was determined to be HIV positive and to have acquired immunodeficiency syndrome (AIDS). A biopsy of a femoral node was diagnostic of PH. His systemic lymphadenopathy appeared to resolve with anti-retroviral therapy. This tumor should be considered within the differential diagnoses of pediatric and immunocompromised patients.

Masson's tumour in the right parietal lobe after stereotactic radiosurgery for cerebellar AVM: case report and review.

We present a 50-year-old patient who had undergone stereotactic radiosurgery for a cerebellar vermian arteriovenous malformation. On routine surveillance MR imaging a lesion suggestive of a meningioma was demonstrated and removed. Histologically it was found to be intravascular papillary endothelial hyperplasia (Masson's tumour). The characteristic radiological and histological findings are presented. Aspects of management of this rare tumour are discussed. Given that cases are often found in combination with a vascular abnormality, we discuss the possibility of a change in local haemodynamics after radiosurgery promoting development of this tumour.

Localized reactive angioendotheliomatosis.

We present a unique case of a woman with multiple painful dermal lesions localized to the left upper quadrant of the body. Histological investigation revealed microvascular thrombosis with capillary-wall proliferation. Further investigation revealed a very high anticardiolipin IgG titre and a left subclavian stenosis, presumably providing the reduced blood flow and relative hypoxia to allow microthromboses to occur in the presence of a thrombophilic tendency. Similar clinical and histological features have been reported in patients with the antiphospholipid syndrome and cases of reactive angioendotheliomatosis (RAE). This case represents a unique variant of RAE.

Vascular tumors of infancy and childhood: beyond capillary hemangioma.

Vascular tumors of infancy and childhood represent a number of clinicopathologically distinct entities for which precise histopathological diagnosis is often essential in determining effective therapeutic approach. Unfortunately, pathologists and clinicians alike have traditionally tended to lump these tumors, in addition to small vessel vascular malformations, under overly generic terms like capillary hemangioma that do little, if anything, to guide proper clinical management. In the last decade this nosologic oversimplification has begun to wane as important new diagnostic tools and better understanding of etiology have evolved, facilitated by international recognition of the need for a multidisciplinary approach in dealing with these perplexing and often clinically devastating lesions. This article provides a brief historical perspective on this progress, and then focuses on the current clinical, histological, and immunophenotypical features that distinguish the major types of vascular tumors of infancy and childhood, also reviewing new evidence regarding their mechanisms of pathogenesis.

Kaposiform hemangioendothelioma associated with Milroy's disease (primary hereditary lymphedema).

Kaposiform infantile hemangioendothelioma (KHE) is a rare recently characterized, locally aggressive, endothelial-derived neoplasm that occurs exclusively in the pediatric age group. Milroy-Nonne disease (primary hereditary lymphedema) is an uncommon congenital entity with familiar history of lower limb edema as typical clinical features. An 8-year-old boy developed a hard painless mass in the right leg 7 years after the diagnosis of congenital primary lymphedema of the right lower extremity. Histopathological analysis of the tumor showed the typical findings of the KHE. To our knowledge this is the first reported case of a KHE engrafting on this infrequent benign lymphatic anomaly.

Long-term exposure of E-mu-Pim1 transgenic mice to 898.4 MHz microwaves does not increase lymphoma incidence.

A total of 120 E mu-Pim1 heterozygous mice and 120 wild-type mice were exposed for 1 h/day 5 days/week at each of the four exposure levels in "Ferris-wheel" exposure systems for up to 104 weeks to GSM-modulated 898.4 MHz radiation at SARs of 0.25, 1.0, 2.0 and 4.0 W/kg. In addition, 120 heterozygous and 120 wild-type mice were sham-exposed; there was also an unrestrained negative control group. Four exposure levels were used to investigate whether a dose-response effect could be detected. Independent verification confirmed that the exposures in the current study were nonthermal. There was no significant difference in the incidence of lymphomas between exposed and sham-exposed groups at any of the exposure levels. A dose-response effect was not detected. The findings showed that long-term exposures of lymphoma-prone mice to 898.4 MHz GSM radiofrequency (RF) radiation at SARs of 0.25, 1.0, 2.0 and 4.0 W/kg had no significant effects when compared to sham-irradiated animals. A previous study (Repacholi et al., Radiat. Res. 147, 631-640, 1997) reported that long-term exposure of lymphoma-prone mice to one exposure level of 900 MHz RF radiation significantly increased the incidence of non-lymphoblastic lymphomas when compared to sham-irradiated animals.

Reactive angioendotheliomatosis secondary to dermal amyloid angiopathy.

Reactive angioendotheliomatosis (RAE) is a rare benign cutaneous vascular proliferation characterized by intravascular hyperplasia of endothelial cells and tuft-like proliferation of vessels. A 75-year-old man had erythematous and violaceous macules, some stellate and others arranged in a livedoid pattern, evolving toward necrosis with central areas having an "atrophie blanche" appearance spread on the trunk, inguinal folds, and right thigh. He was on hemodialysis and had a benign monoclonal gammopathy. Cutaneous biopsy revealed RAE characterized by the proliferation of epithelioid and spindle-shaped cells in superficial and middermis lining vascular channels, arranged in clusters, and sometimes displaying an intravascular growth pattern. These cells stained for CD31, CD34, and actin. Interestingly, prominent amyloid deposits were found in the wall of some vessels in deep dermis, often causing obstruction of their lumina. The cause of RAE is unknown, but it can be associated with infections, antiphospholipid syndrome, dysglobulinemia, cryoproteinemia, and lower extremities arteritis, and it may occur near arteriovenous fistulas. In this patient, we believe that RAE was caused by obliteration of dermal vessels by amyloid deposits. Indeed, it is thought that RAE could be caused by ischemia secondary to vascular obstruction. This is the first reported patient with RAE associated with amyloid deposits.