Multifocal kaposiform hemangioendothelioma of soft tissue with bilateral pulmonary involvement in an adolescent

Adult-onset multifocal kaposiform hemangioendothelioma in the bone marrow, lung, liver, and brain: a case report

Kaposiform hemangioendothelioma (KHE), a rare form of vascular neoplasm, is typically seen in children. In this paper, we report a unique case of KHE replacing bone marrow tissue mimicking myeloproliferative neoplasm with additional involvement in the lung, liver, and brain in a 60-year-old Caucasian woman. The patient was initially seen in the hematology department for the chief complaint of epigastric pain and anemia. Abdominal magnetic resonance imaging (MRI) revealed mild splenomegaly with iron deposition secondary to extramedullary hematopoiesis. Additional workup was inconclusive. Subsequent bone marrow and lung biopsies eventually revealed bone marrow with extensive grade 3 fibrosis and multiple foci of low-grade vasoformative neoplasm in the lung suggestive of KHE. Although rare, KHE can present as an aggressive disease with indolent behavior in adults and can be distinguished from other vascular malignancies based on histopathology and imaging findings.

18F-FDG PET/CT Findings in a Woman With Kaposiform Hemangioendothelioma in the Sacrum

ABSTRACT

Kaposiform hemangioendothelioma is a rare vascular tumor with borderline malignancy and is typically diagnosed in infancy or early childhood. It most commonly affects cutaneous tissues, whereas the subtype with only primary bone involvement is extremely rare. Herein, we report a case of Kaposiform hemangioendothelioma involving the sacrum in a 37-year-old woman, with intense 18F-FDG accumulation in the lytic lesion on PET/CT. This case indicates that Kaposiform hemangioendothelioma with the primary bone involvement should be taken into consideration as a rare differential diagnosis for lytic lesions with increased 18F-FDG uptake on PET/CT.

Cellular Variant of Kaposiform Lymphangiomatosis: A Report of Three Cases, Expanding the Morphologic and Molecular Genetic Spectrum of this Rare Entity

Kaposiform lymphangiomatosis (KLA) is a very rare form of generalized lymphatic anomaly, consisting of a diffuse proliferation of abnormal, dilated lymphatics and small fascicles of hemosiderin-laden spindled lymphatic endothelial cells. KLA occurs in children and young adults and may present with multicentric disease, pleural and pericardial effusions, and life-threatening coagulopathy. Genetically, KLA most often harbor somatic activating mutations in NRAS. We recently encountered 3 cases of KLA with cellular features, resembling kaposiform hemangioendothelioma (KHE) and studied their clinicopathologic, radiologic and molecular genetic features. The patients (1 male, 2 females; ages 2 years, 2 months, 4 years) presented with multicentric disease involving skin, soft tissue, bone and spleen, and thrombocytopenia/coagulopathy. Advanced imaging studies confirmed multicentric disease. Biopsies (skin, soft tissue, bone, spleen) demonstrated both conventional KLA and much more cellular foci, consisting of sheets, nodules, glomeruloid structures, and "sieve-like" arrays of lymphatic endothelial cells (positive for CD31 and D2-40). Cellular areas superficially resembled KHE but displayed more epithelioid cytology and lacked surrounding hyaline fibrosis and minute platelet aggregates. Molecular genetic studies demonstrated NRAS c.181C>A p.Q61K (Gln61Lys) in 2 specimens from one patient and HRAS p.A59_Q61delinsGGSIL in another. Two patients were treated with sirolimus; all are currently alive with stable disease. We conclude that cellular morphology in KLA, a previously undescribed feature, does not appear to be associated with clinical features, site of disease, mutation type, response to sirolimus, or outcome. Although cellular KLA may mimic KHE, there are sufficient clinical, morphologic, and genetic differences such that these are likely unrelated diseases.

Kaposiform Hemangioendothelioma with Kasabach-Merritt Phenomenon

A 3-y-3-mo old male child presented with massive hypertrophy and bluish-purple discoloration of the left upper limb and adjacent chest wall of 3 mo duration. There was no h/o fever, weight loss, painful large joint swelling, or any bleeding manifestations. He had spindle like nonprogressive, painless swelling of all fingers of the left hand since infancy. The child was moribund with microangiopathic hemolytic anemia, thrombocytopenia, and consumptive coagulopathy without sepsis. He received multiple transfusions of fresh frozen plasma (FFP), platelets, and packed RBC. Paradoxical worsening of symptoms with platelet transfusions and radiological evidences led to the diagnosis of a very rare congenital multifocal vascular tumor, kaposiform hemangioendothelioma (KHE) with Kasabach-Merritt phenomenon (KMP). The index case of KHE was multifocal with cutaneous lesions, osteolytic bony lesions of all phalanx and metacarpals of the left hand, and intrathoracic extension. It was successfully managed with a combination of steroid, vincristine and sirolimus.

Local suture ligation-assisted percutaneous sclerotherapy for Kasabach-Merritt phenomenon-associated kaposiform haemangioendothelioma

Kaposiform haemangioendotheliomas (KHEs) complicated by the Kasabach-Merritt phenomenon (KMP) are rare and severe neoplastic lesions often associated with locally aggressive disease, consumption coagulopathy and high mortality rates. Current regimens have yet to achieve a satisfactory therapeutic effect. Thus, an effective and minimally invasive approach for treating complex KHE/KMP cases is necessary for clinical management. The present case series describes patients with KHE/KMP who underwent local suture ligation-assisted percutaneous sclerotherapy to minimise surgical trauma and ensure effective treatment. Between September 2015 and September 2017, 3 consecutive patients with KHE/KMP underwent staged local suture ligation-assisted percutaneous sclerotherapy. Of these patients, 2 presented with medical histories of corticosteroid treatment with unsatisfactory outcomes. The patients underwent a stepwise synthetic serial therapy programme consisting of percutaneous sclerotherapy and adjunctive pharmacotherapy accompanied by a suture ligation procedure. Clinical, radiological, pathological and laboratory data were analysed to evaluate the outcomes of the therapy. All patients were successfully managed with the proposed procedure. Significant relief of clinical symptoms and improvements in haematological indicators were achieved. No recurrence or complications were observed during regular follow-up (4, 19 and 28 months). In conclusion, local suture ligation-assisted percutaneous sclerotherapy was demonstrated to be a safe and effective treatment for KHE/KMP, being minimally invasive, involving simple manipulation and providing a clear treatment benefit in certain cases. Further studies involving larger sample sizes are required to thoroughly evaluate the procedure, which can potentially be used as a novel therapeutic option for KHE/KMP treatment.

Primary pleural intermediate hemangioendothelioma with pleural effusion as the only manifestation

Intermediate hemangioendothelioma is a group of rare tumors of vascular origin that show a borderline biological behavior and commonly arise in extremities, trunk, head or neck. Intermediate hemangioendothelioma originating in pleura is extremely rare. Herein we describe a case of primary pleural intermediate hemangioendothelioma in a 48-year-old man presenting with pleural effusion only. The patient was diagnosed by pleura biopsy and immunohistochemistry in our hospital. Even though neither systemic chemotherapy nor surgery was applied, he got relieved gradually and sustained asymptomatic during follow-up for 10 months.

Abdominal Kaposiform Hemangioendothelioma Associated With Lymphangiomatosis Involving Mesentery and Ileum: A Case Report of MRI, CT, and 18F-FDG PET/CT Findings

Kaposiform hemangioendothelioma (KH) is a rare vascular tumor of intermediate malignancy that occurs mainly in the childhood. Adult patients with KH are rare. Imaging findings of KH have rarely been reported before. We present magnetic resonance imaging (MRI), computed tomography (CT), and fluorine-18-fluorodeoxyglucose (F-FDG) positron emission tomography (PET)/CT findings in an adult patient with KH associated with lymphangiomatosis involving mesentery and ileum.A 22-year-old female complained of a 9-month history of intermittent melena, weakness, and palpitation. Laboratory tests revealed anemia and hypoproteinemia. Fecal occult blood test was positive. Abdominal enhanced MRI and CT showed a large abdominal mass involving mesentery and ileum. On enhanced MRI, there were many hypervascular nodules in the mass. On FDG PET/CT, the mass and the nodules showed slight FDG uptake. Small bowel capsule endoscopy showed numerous grape-shaped red nodules in the luminal wall of the involved ileum. The patient underwent resection of the abdominal mass and a segment of the ileum invaded by the abdominal mass. KH arising within lymphangiomatosis involving mesentery and ileum was confirmed by pathology. After surgery, the patient's symptoms improved.This is the first case of KH associated with lymphangiomatosis involving mesentery and ileum. In this case, the lymphangiomatosis overshadowed the small tumor nodules resulting in unusual imaging findings. Familiarity with these imaging findings is helpful for diagnosis and differential diagnosis of KH.

Recent advances in the pathobiology and management of Kasabach-Merritt phenomenon

Kasabach-Merritt Phenomenon (KMP) refers to the clinical constellation of thrombocytopenia, consumptive coagulopathy and purpura associated with Kaposiform haemangioedothelioma or tufted angioma, but not the more common infantile haemangioma. It shows a variable and unpredictable response to traditional pharmacological agents, such as steroids, vincristine or interferon alpha 2a or 2b. More recently, the interaction between platelets and endothelial cells and the proangiogenic phenotype that results has been recognized to underly the pathogenesis of this disorder. Recent efforts have attempted to target the platelet by using antiplatelet agents and by the withholding of platelet transfusions even in those patients who have significant thrombocytopenia and laboratory evidence of coagulopathy. Excellent response rates and prompt results have been achieved by combining antiplatelet therapy with vincristine, without the need for steroid use. This synergistic approach moves away from the conventional wisdom of treating the underlying lesion to control the coagulopathy. Sirolimus, which is directed against the PI3/AKT/mTOR downstream signalling pathway involved in lymphangiogenesis, has also shown promising results, although further study is needed.