Intratumoral consumption of indium-111 labeled platelets in a patient with hemangiomatosis and intravascular coagulation (Kasabach-Merritt syndrome)

A Xenograft Model of Kaposiform Hemangioendothelioma in Nude Mice Recapitulates Kasabach-Merritt Phenomenon

BACKGROUND

Kasabach-Merritt phenomenon (KMP) is characterized by profound thrombocytopenia and consumptive coagulopathy associated with vascular tumors, such as Kaposiform hemangioendothelioma (KHE). The pathogenesis of KMP remains unclear and its treatment is challenging. In this study, we tried to establish an animal model of KMP, which may facilitate the research on the etiology and new treatment.

METHODS

A fresh sample of KHE from a one-month-old female infant with KMP was scissored into pieces and transplanted subcutaneously into the back of the nude mice. Blood routine examination was performed before the transplantation and 2, 4, 8, 12, and 16 weeks after the transplantation. Transplanted tumors were harvested 2, 4, 8, 12, and 16 weeks after the transplantation. H-E staining, immunohistochemistry staining of cluster of differentiation 31 (CD31) and alpha-smooth muscle actin (α-SMA), and ultrastructural observation were performed on the plugs.

RESULTS

Blood test showed a significant decrease in the number of platelets 2 weeks after transplantation. The number of platelets showed an overall trend of recovery from 2 weeks despite a slight decrease at 12 weeks after transplantation. There was no significant difference in the platelet count at 16 weeks after transplantation compared with the original state. H-E staining showed abundant irregular blood sinuses in the transplanted tumors with plenty of blood cells 2 weeks after the transplantation. 4, 8, and 12 weeks after transplantation, the density of blood sinuses decreased progressively. 16 weeks after transplantation, the plugs involuted into fibrous tissue. Immunohistochemistry staining showed the positive expression of CD31 in the endothelial cells and α-SMA in the perivascular cells. Ultrastructural observation also showed the features of KHE and progressive evolution of the tumors.

CONCLUSIONS

We successfully established an experimental model of KMP by the xenograft of KHE in nude mice, which manifested profound thrombocytopenia and typical pathological structure.

Primary angiosarcoma of the breast complicated by the syndrome of disseminated intravascular coagulation (DIC): Case report and literature review

Primary angiosarcoma of the breast (PAB) accounts for 0.04% of all breast malignant tumors. It affects young women usually at third or fourth decades of life. PAB clinically manifests as a painless, movable mass with sharp limits. A bluish red discoloration of the overlying skin is often observed. Enlargement of axillary lymph nodes generally does not occur. Angiosarcoma of the breast has a very poor prognosis due to the tendency to metastasize haematogenously and high frequency of local recurrence. Mastectomy and chemotherapy are preferable treatment choices. This paper presents a case of primary angiosarcoma of the breast with a syndrome of disseminated intravascular coagulation (DIC).

Kaposiform hemangioendothelioma complicated by Kasabach-Merritt phenomenon: ultrastructural observation and immunohistochemistry staining reveal the trapping of blood components

Kaposiform hemangioendothelioma (KHE), a borderline tumor of endothelial origin, is associated with Kasabach-Merritt phenomenon, characterized by profound thrombocytopenia and consumptive coagulopathy resulting from the localized intravascular coagulation (LIC) in the tumor. Previous studies have suggested that the trapping of blood components, including platelets, may underlie the LIC in KHE. However, more evidence is needed to support this hypothesis. In this study, one case of a Chinese infant with a KHE in the left arm was complicated by Kasabach-Merritt phenomenon. The tumor was partially resected and the sample was used for ultrastructural observation and immunohistochemistry staining of Glut-1. Ultrastructural observation found the trapping of erythrocytes, platelets, macrophages, and lymphocytes in the slit-like channels of the tumor nodules, and phagocytic vesicles in the cytoplasm of neoplastic cells. Immunohistochemistry staining further showed numerous Glut-1(+) erythrocytes in the channels. In conclusion, our results provided compelling morphological evidence of the trapping of blood components in KHE, which may interpret the LIC in the tumor and subsequent consumptive coagulopathy.

Mediastinal and neck kaposiform hemangioendothelioma: report of three cases

Kaposiform hemangioendothelioma is an aggressive vascular tumor, named for its striking histologic resemblance to Kaposi sarcoma and locally invasive growth. Mortality is high, and ranges from 10% to 24% for all kaposiform hemangioendothelioma lesions, with a significantly higher mortality for deep soft-tissue or visceral lesions occurring in infants less than 6 months. Mediastinal and neck kaposiform hemangioendothelioma in particular merit special discussion, as involvement of these critical anatomic locations results in significant site-specific therapeutic challenges due to invasion of vital structures, inherent delays in establishing histopathologic confirmation, and difficulties in monitoring disease status. We report our experience with three cases of mediastinal and neck kaposiform hemangioendothelioma, emphasizing the unique diagnostic and management challenges, variable response to treatment and outcome of this anatomic variant of kaposiform hemangioendothelioma.

Transgenic rabbits with increased VEGF expression develop hemangiomas in the liver: a new model for Kasabach-Merritt syndrome

Clinical studies have provided ample evidence that high (either systemic or local) levels of vascular endothelial growth factor (VEGF) are associated with several pathophysiological disorders, including hemangiomas. To investigate whether elevated VEGF expression could directly affect these disorders, we created a transgenic (Tg) rabbit model with increased hepatic expression of the human VEGF(165) transgene under the control of the human alpha-antitrypsin promoter. Tg rabbits exhibited marked hepatomegaly, with livers 2.5-fold heavier than those of control rabbits. Histological analysis revealed that the livers of Tg rabbits showed prominent dilation of the sinusoids and formed various-sized blood vessel networks, a feature of diffuse hemangiomas. Immunohistochemical staining revealed that the hepatocytes produced VEGF(165), whereas plasma VEGF(165) was not detected. Furthermore, Tg rabbits suffered from hemolytic anemia, thrombocytopenia and splenomegaly, which was associated with marked extramedullary hematopoiesis. The manifestations of Tg rabbits mimic many of the features of hemangiomatous disorders in humans such as the Kasabach-Merritt syndrome, and therefore this model may be potentially useful for the study of the pathogenesis and complications of hemangiomas as well as the investigation of angiogenesis inhibitors.

Hemostatic and hematological abnormalities in gain-of-function fps/fes transgenic mice are associated with the angiogenic phenotype

The Fps/Fes tyrosine kinase has been implicated in the regulation of hematopoiesis and inflammation. Mice expressing an activated variant of Fps/Fes (MFps) encoded by a gain-of-function mutant transgenic fps/fes allele (fps(MF)) exhibited hematological phenotypes, which suggested that Fps/Fes can direct hematopoietic lineage output. These mice also displayed marked hypervascularity and multifocal-hemangiomas which implicated this kinase in the regulation of angiogenesis. Here we explored the potential involvement of Fps/Fes in the regulation of hemostasis through effects on blood cells and the vascular endothelium. Hematological parameters of fps(MF) mice were characterized by peripheral blood analysis, histology, and transmission electron microscopy. Hemostasis parameters and platelet functions were assessed by flow cytometry and measurements of activated partial thromboplastin time, prothrombin time, thrombin clot time, platelet aggregation, bleeding times and in vitro fibrinolytic assays. Hematological and morphological analyses showed that fps(MF) mice displayed mild thrombocytopenia, anemia, red cell abnormalities and numerous hemostatic defects, including hypofibrinogenemia, hyper-fibrinolysis, impaired whole blood aggregation and a mild bleeding diathesis. fps(MF) mice displayed a complex array of hemostatic perturbations which are reminiscent of hemostatic disorders such as disseminated intravascular coagulation (DIC) and of hemangioma-associated pathologies such as Kasabach-Merritt phenomenon (KMS). These studies suggest that Fps/Fes influences both angiogenic and hemostatic function through regulatory effects on the endothelium.

Splenic tumour: a clinicopathological study

Splenic tumours are occasionally found during routine physical check-ups or elective abdominal image studies. Histologically, most splenic tumours are of benign vascular origin. To avoid unnecessary surgery for asymptomatic patients with benign splenic tumours and clarify the clinicopathological features of spleen tumours, this study gathered 44 cases of primary or isolated metastatic spleen tumours confirmed by pathology from surgery specimens or biopsies. The differences in clinicopathological features and image presentations between benign and malignant spleen tumour were investigated. Thirty-two cases involved benign tumours while 12 cases were malignant. Among the benign tumours, vascular originating tumours were most common (with 14 cases of cavernous haemangiomas, 13 cases of lymphangioma, three cases of lymphangiohaemangioma and one case of Littoral cell angioma). Notably, one, case of inflammatory pseudotumour because of Schistosoma parasite infection was also noted. Among the malignant tumours, there were four cases of angiosarcomas with vascular endothelium origins, as well as lymphomas and six metastatic tumours. Image studies were non-specific. Image study alone is an inadequate basis for making differential diagnoses between benign and malignant tumours. Instead, pathological studies are required for a final diagnosis. Using previous studies and this investigation, fine needle aspiration biopsy of spleen tumours with the help of ultrasonic or computed tomography appears a safe and effective method for obtaining biopsy specimens. Splenectomy is recommended only for patients with malignancies or complications such as intractable abdominal pain, coagulopathy or tumour rupture with an unstable haemodynamic state.

Intratumoral consumption of indium-111-labeled platelets in a child with splenic hemangioma and thrombocytopenia

The authors report Kasabach-Merritt syndrome (KMS) in a patient with thrombocytopenia and splenic hemangioma. A 13-month-old boy with a history of anemia, thrombocytopenia, and abdominal mass was admitted to the hospital. The scintigraphic studies showed that a large mass contiguous to the spleen was responsible for the platelet uptake. After partial splenectomy, the platelet count returned to normal. This report of KMS in a child with splenic hemangioma suggests that the scintigraphic studies are mandatory to confirm diagnosis. Indium-111-labeled platelets are useful in identifying hemangiomatous sequestration of platelets in patients with thrombocytopenia.

Treatment of the Kasabach-Merritt syndrome with pegylated recombinant human megakaryocyte growth and development factor in mice: elevated platelet counts, prolonged survival, and tumor growth inhibition

Kasabach-Merritt Syndrome (KMS) is seen in children with large vascular tumors. KMS is characterized by very low platelet counts and a consumption of coagulation factors causing life-threatening complications. It has been proposed that thrombopenia in these patients is caused by intratumoral trapping of platelets. The truncated form of the cMpl-receptor ligand thrombopoietin, pegylated human megakaryocyte growth and development factor (Peg-rHuMGDF), is an agent that stimulates platelet production. We hypothesized that stimulation of the platelet production would prevent the life-threatening complications of patients with KMS owing to low platelet counts. In a mouse model of KMS, with tumors derived from a hemangioendothelioma cell line, we studied the effect of Peg-rHuMGDF. Treatment with Peg-rHuMGDF (10 microg/kg/day intraperitoneally) increased platelet counts by 7-8-fold compared with control tumor-bearing mice after 11 d of treatment (p < 0.001, n = 8). Survival was significantly increased, with 50% of treated animals alive at 1 mo versus 0% in untreated controls. Interestingly, we also observed an inhibition of tumor growth by 75% (p < 0.001, n = 8). Hematoxylin and eosin staining showed fresh fibrin clots in the treated tumors, suggesting that higher platelet counts caused intravascular thrombosis of tumor vessels. We conclude that increased platelet production in this model of KMS resulted in an antivascular tumor effect via platelet trapping. Further, we propose that thrombopoietin may be of critical value in preventing life-threatening complications from KMS.

Isolated diffuse hemangiomatosis of the spleen with Kasabach-Merritt-like syndrome

AIMS

Diffuse haemangiomatosis of the spleen is a rare benign vascular condition occurring as a manifestation of systemic angiomatosis or, less commonly, confined to the spleen. It is sometimes accompanied by severe disturbance of blood coagulation. The goal of this study was to characterize an additional case of isolated diffuse haemangiomatosis of the spleen and to determine the histogenesis of this lesion which remains obscure.

METHODS AND RESULTS

We describe a case of isolated diffuse haemangiomatosis of the spleen in which histological and immunohistological findings suggested the possibility of a malformative tumour-like lesion. The pathological cavernous vessels were distributed randomly through the red pulp, without continuity with sinuses. The endothelial cells expressed vimentin, factor VIII related antigen and CD34, but not CD8. Some cells lining the sinus lumen expressed CD68, lysozyme and myeloperoxidase. In addition, trabecular veins presented with intimal thickening. These results allow making a diagnosis between diffuse haemangiomatosis and other tumours/tumour-like lesions of the spleen, especially littoral cell angioma, splenoma and peliosis.

CONCLUSION

If diffuse haemangiomatosis is usually classified as a benign proliferation of endothelial cells, we suggest that diffuse haemangiomatosis, when confined to the spleen, could be a tumour-like vascular lesion. In this hypothesis, the aetiology may be hamartomatous or malformative as is suspected in arterio-venous haemangioma of the lower extremities. The histogenesis is still questionable and no definitive proof in favour of one or the other hypothesis has been reported.

Kasabach-Merritt syndrome: identification of platelet trapping in a tufted angioma by immunohistochemistry technique using monoclonal antibody to CD61

Kasabach-Merritt syndrome (KMS) consists of large and rapidly growing vascular tumors associated with thrombocytopenia, generalized petechiae, and bleeding. The cause of the thrombocytopenia is thought to be related to the trapping of platelets by the abnormal endothelium of the tumor. We report an infant with KMS that developed in association with a large tufted angioma. In this case we directly demonstrated platelet trapping in the vascular lumen of the tumor by an immunohistochemical technique using a monoclonal antibody against CD61, a marker of platelets and megakaryocytes.

Cutaneous angiosarcoma with thrombocytopenia

Thrombocytopenia was observed in 3 patients with cutaneous angiosarcoma of the scalp and face. A sudden decrease in the platelet count occurred in association with rapid enlargement of primary or metastatic lesions. Neither antiplatelet antibody nor platelet-associated IgG was detected. Increased serum levels of beta-thromboglobulin and platelet factor 4 indicated that platelets were destroyed and consumed within the vascular bed of the tumor. Prominent PECAM-1 expression on tumor cells may be involved in intratumoral platelet aggregation and consumption. We suggest that the sudden development of profund thrombocytopenia in patients with angiosarcoma may suggest either rapid growth of the primary tumor or herald the development of metastatic disease.

Kasabach-Merritt syndrome in two neonates

Two neonates with a giant hemangioma associated with thrombocytopenia (Kasabach-Marritt syndrome) have been managed at Kure National Hospital. The first case was initially difficult to distinguish from overwhelming infection or other tumors but improved after radiotherapy. The second case was resistant to radiation and steroid therapy. Magnetic resonance imaging determined a tumor extending into the surrounding soft tissues better than did enhanced computed tomography. Subtotal excision of the tumor and various drugs were effective only transiently and 51Cr-labeled platelets sequestrated into the residual hemangioma. Severe thrombocytopenia persisted for approximately 15 months requiring extra care for head and body contusions, but finally improved by treatment with platelet-active drugs such as acetylsalicylic acid, dipyridamole, and pentoxifylline.

Kasabach-Merritt syndrome

The Kasabach-Merritt syndrome includes the triad of vascular tumors, thrombocytopenia, and a hemorrhagic diathesis. The vascular tumors are usually benign but the associated coagulopathy may be life threatening. We describe a patient whose clinical course illustrates the potential difficulties in management.

Antifibrinolytic therapy in the management of the Kasabach Merritt syndrome

The Kasabach Merritt syndrome consists of thrombocytopenia, microangiopathic hemolytic anemia, and a localized consumption coagulopathy that develops within the abnormal vascular channels of a hemangioma. In general, these patients demonstrate only mild abnormalities of screening clotting tests, but they can potentially develop life-threatening complications. We present a patient who developed a severe anemia that was refractory to erythrocyte transfusions. Treatment with epsilon-aminocaproic acid to inhibit fibrinolysis and cryoprecipitate to replenish his deficient circulating fibrinogen interrupted the cycle of his systemic coagulopathy and enabled us to transfuse him to a normal hematocrit.

Techniques for measuring red cell, platelet, and WBC survival

Blood cell survival studies yield valuable information concerning production and destruction of cells circulating in the bloodstream. Methodologies for the measurement of red cell survival include nonisotopic methods such as differential agglutination and hemolysis. The isotopic label may be radioactive or, if not, will require availability of a mass spectrograph. These methods fall into two categories, one where red cells of all ages are labeled (51Cr, DFP32, etc.) and those employing a cohort label of newly formed cells (14C glycine, 75Se methionine, etc.). Interpretation of results for methodology employed and mechanism of destruction, random or by senescence, are discussed. A similar approach is presented for platelet and leukocyte survival studies. The inherent difficulties and complications of sequestration, storage, and margination of these cells are emphasized and discussed.