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Abstract: Pseudomyogenic hemangioendothelioma (PHE) is an uncommon mesenchymal neoplasm of intermediate malignant potential showing endothelial differentiation. Around 20 cases of primary osseous PHE have been reported to date. A 16-year-old boy presented with complaints of pain in his right leg. Imaging revealed multifocal intramedullary and cortical-based lytic lesions involving long and small bones. Microscopic examination revealed plump, spindled cells arranged in fascicles and admixed "epithelioid" and "rhabdoid" cells sans vasoformative areas. By immunohistochemistry, the lesional cells were reactive for AE1/AE3, CD31, Erg, Fli1, and SMA, while immunonegative for CD34, myogenin, and S100. Nuclear expression of the INI1/SMARCB1 protein was retained. PHE is a rare entity, more so as a primary osseous lesion; therefore, awareness of the presence of this entity in the bone is the key to making a diagnosis. We discuss its clinicopathological features, differential diagnosis, and an attempt a short review of the literature., (Copyright © 2023 Copyright: © 2023 Indian Journal of Pathology and Microbiology.)

Kaposiform hemangioendothelioma(KHE) without Kasabach-Merritt phenomenon is a rare tumor primarily observed in pediatric patients; however, its documentation in the literature remains limited. We reported about a 1-year-old boy diagnosed with superficial KHE who received oral propranolol in combination with topical sirolimus and reviewed relevant reports and treatment of superficial KHE., Competing Interests: The authors report no conflicts of interest in this work., (© 2024 Dang and Ren.)

The term "hemangioendothelioma" is used for endothelial neoplasms of intermediate malignancy and describes a group of rare neoplasms having biologic behavior falling in between that of the benign hemangiomas and fully malignant angiosarcomas. The hemangioendotheliomas fall into several specific, clinicopathologically and genetically distinct entities, specifically epithelioid hemangioendothelioma, kaposiform hemangioendothelioma, papillary intralymphatic angioendothelioma and retiform hemangioendothelioma (hobnailed hemangioendothelioma), pseudomyogenic hemangioendothelioma, composite hemangioendothelioma, and YAP1::TFE3-fused hemangioendothelioma. The clinical, morphologic, immunohistochemical, and genetic features, and the differential diagnosis of each of these rare entities are discussed in this review., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The diagnosis of vascular anomalies remains challenging due to significant clinical heterogeneity and uncertain etiology. Evaluation using biopsy and/or genetic testing for somatic variants is invasive, expensive, and prone to sampling error. There is great need for noninvasive and easily measured blood laboratory biomarkers that can aid not only in diagnosis, but also management of treatments for vascular anomalies. Angiopoietin-2, a circulating blood angiogenic factor, is highly elevated in patients with kaposiform hemangioendothelioma with Kasabach-Merritt phenomenon and kaposiform lymphangiomatosis. Here, we describe our clinical experience using serum angiopoietin-2 as a biomarker for diagnosis and monitoring response to treatment., (© 2024 The Authors. Pediatric Blood & Cancer published by Wiley Periodicals LLC.)

Rationale: Kaposiform hemangioendothelioma is an aggressive vascular tumor that is often associated with life-threatening coagulopathies and Kasabach-Merritt phenomenon. Pathologic biopsies can provide a good basis for diagnosis and treatment. Therapy with srolimus combined with glucocorticoids may offer patients a favorable prognosis., Patient Concerns: A large purplish-red mass on the knee of a child with extremely progressive thrombocytopenia and refractory coagulation abnormalities. Conventional doses of glucocorticoids alone failed to improve coagulation abnormalities and the child developed large cutaneous petechiae and scalp hematomas., Diagnosis: Kaposiform hemangioendothelioma combined with Kasabach-Merritt phenomenon., Interventions: The patient received prednisolone 2.0 mg/kg*d for 4 days. Blood products were transfused to ensure vital signs and to complete the pathologic biopsy. Sirolimus combined with prednisolone was given after clarifying the diagnosis of Kaposiform hemangioendothelioma., Outcomes: The tumor basically disappeared on examination and the ultrasound showed a subcutaneous hyperechoic mass with normal blood flow., Lessons: Sirolimus combined with glucocorticoids is effective in controlling Kasabach-Merritt phenomenon and pathologic biopsy is important for definitive diagnosis., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

The conventional treatment of Kasabach-Merritt Phenomenon (KMP) consists of corticosteroids with vincristine/vinblastine or others. The aim of the study is to compare the first-year direct costs and effectiveness between sirolimus and conventional treatment. A retrospective case-control study of KMP patients was conducted at a mean age of 9 months ( 1 day to 12 years) between 2000 and 2022 from four tertiary centers in Thailand. The direct costs, hematologic and clinical complete response (HCR, CCR), hospitalization, length of stay, and complications were compared. Of 29 patients, 13 underwent sirolimus (four upfront and nine were refractory to the conventional). The first-year total cost had no statistically significant difference between sirolimus VS conventional treatment (8,852.63 VS 9,083.56 USD: p value: 0.94). The therapeutics achievement was the same in both HCR (244.75 VS 168.94 days; p value: 0.60) and CCR (419.77 VS 399.87 days; p value: 0.90). The subgroup analysis of the first-line sirolimus ( n  = 4) compared with the conventional ( n  = 25) showed a more reduced total cost (4,907.84 VS 9,664.05 USD; p value: 0.26) rendered net total cost of -4,756.21 USD per patient (cost saving). A more significant contrast of therapeutic achievement by reduction of both HCR (11.67 VS 224.20 days; p value: 0.36) and CCR (38.50 VS 470.88 days; p value: 0.04) was shown. The sirolimus had no difference in hospitalization, length of stay, and complications. Even though, it was unable to identify significant differences in cost-effectiveness. Sirolimus is suitable for all patients who have diagnosis of KMP either for rescue therapy or first-line treatment.

Background: Kaposiform hemangioendothelioma (KHE) is a rare, locally aggressive vascular tumor that often occurs in infants and young children. The goal of this study was to analyze the clinical characteristics of KHE patients with bone destruction and provide clinical guidance for diagnosis and treatment., Methods: We conducted a descriptive cohort study with follow-up from January 2007 to January 2023 to collect demographic information and tumor-related clinical information from KHE patients with bone destruction., Results: A total of 269 KHE patients were included in the study, of whom 70 (26.0%) patients had tumors with bone destruction. The median age at diagnosis of patients with bone destruction was 19.0 months, which was much later than that of patients without bone destruction (P < 0.001). Patients with bone destruction were more likely to have a decreased range of motion (ROM) (P < 0.001). Metaphysis involvement was more likely to occur in the lower limb bones (P = 0.039), and the lower limb bones were more likely to be associated with decreased ROM (P = 0.001). Tumors involving extracompartmental bone were more likely to have decreased ROM (P = 0.003) and exhibit the Kasabach-Merritt phenomenon (P = 0.006)., Conclusions: Based on the rarity and significant heterogeneity of KHE patients with bone destruction, we should give full play to the role of multidisciplinary teams in addressing disease to reduce the long-term complications of KHE with bone destruction and improve the quality of life of patients., Type of Study: Prognostic Study., Level of Evidence: Level II., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective: This retrospective study aimed to observe the efficacy of transcatheter arterial chemoembolization (TACE) combined with sirolimus in the treatment of haemangioma combined with the Kasabach-Merritt phenomenon (KMP)., Methods: A total of 11 infants with KMP who were treated at our hospital from January 2016 to September 2021 were selected and treated with arteriosclerosis embolotherapy using a microsphere emulsion formed by bleomycin + ultra-fluid lipiodol + dexamethasone + contrast agent or bleomycin mixed microspheres as the embolising agent. The patients were administered sirolimus orally after TACE. The clinical efficacy and examination indicators before and after treatment were observed and compared., Results: The 11 infants underwent TACE treatment by arteriosclerosis embolotherapy a total of 21 times; of these cases, 10 were cured, and 1 showed a moderate response. There were no cases of non-response or death. The platelet count rose from 10.0 (7.0, 18.0) x 10 9 /L before TACE to 236.0 (188.0, 275.0) x 10 9 /L six months after the first TACE, and the tumour size decreased from 49.0 (43.0, 111.7) cm 3 before TACE to 7.0 (3.5, 17.0) cm 3 six months after the first TACE. The differences were statistically significant (the Z values were -2.943 and -2.934, respectively, p  < 0.05)., Conclusion: The combination of TACE and sirolimus has significant efficacy on critical children with KMP.

Background: Kaposiform hemangioendothelioma (KHE) is a rare vascular neoplasm affecting infants or young children. KHE includes a spectrum of lesions, ranging from small and superficial tumors to large and invasive lesions with Kasabach-Merritt phenomenon (KMP). Currently, no published studies have reported a KHE presenting as thrombocytopenia and Raynaud phenomenon., Case Presentation: A 2-year-old boy with right hand swelling and thrombocytopenia was admitted to our hospital. His right hand turned swelling and red, even occasionally cyanotic. This condition became worse in response to cool environments and improved with warming, and platelet counts were between 50 ~ 80 × 10^9/L. Physical examination on admission revealed the swelling and frostbite-like rash of the right-hand fingers, and the skin temperature of the right hand was lower than the left. On day 3 of admission, chest CT results showed an irregular mass on the right side of the spine. The puncture biopsy demonstrated positive CD31, D2-40, and FLI1 immunohistochemical staining, but negative GLUT1 staining, confirming the diagnosis of KHE. Furthermore, endothelin-1 (ET1) expression levels significantly increased, and eNOS and A20 expression levels significantly decreased comparing with control patients. The patient received methylprednisolone and sirolimus treatments, and his condition gradually improved during the follow-up., Conclusions: We reported the first case of KHE presenting with thrombocytopenia and Raynaud phenomenon. The development of Raynaud phenomenon could be associated with increased ET-1 and reduced eNOS and A20 expressions. Careful differential diagnosis of hidden KHE should be considered in children with thrombocytopenia and Raynaud phenomenon., (© 2023. The Author(s).)

Kaposiform hemangioendothelioma is a rare tumour of vascular origin that rarely occurs in the heart. We provided a rare case of a 26-day-old infant with tachypnoea. Echocardiography showed a solid tumour in the pericardial cavity and a large amount of pericardial effusion. The solid tumour was confirmed by surgery, and the pathology was kaposiform hemangioendothelioma. We analysed this case and reviewed the related literature to explore the clinical features and echocardiographic manifestations to improve the understanding, diagnosis, and treatment of this disease for clinicians and sonographers.

BACKGROUND Papillary intralymphatic angioendothelioma (PILA) is a rare vascular tumor affecting children and young adults, with less than 50 cases reported in the literature. This tumor typically presents in the extremities, exhibits borderline behavior, and has a prominent lymphatic phenotype. Originally thought to be malignant, PILA was later recognized for its borderline behavior and lymphatic features, leading to its current classification as a "rarely metastasizing lymphatic vascular neoplasm". CASE REPORT We present the case of a 10-year-old girl with a 6-year history of a right facial venous malformation, which was ultimately diagnosed as PILA in the background of lymphatic/venous malformation (LVM). After undergoing surgical excision of a right facial soft-tissue tumor, histopathological examination revealed scattered lymphatics and thin-walled vascular channels with blood in skeletal muscle and fibroadipose tissue. Intraluminal papillary proliferation of vascular spaces lined by cytologically bland spindle cells was observed, along with Kaposiform morphology and small-vessel proliferation. Immunohistochemical staining confirmed endothelial cell markers (D2-40, ERG, CD34, and CD31) and numerous CD3(+) lymphocytes in the lumen, surrounded by CD3(+) T lymphocytes and CD20(+) B lymphocytes in the surrounding stroma. The tumor lacked pleomorphism, significant mitotic activity, and necrosis. CONCLUSIONS PILA presents a diagnostic challenge and should be considered in the differential diagnosis of cutaneous vascular neoplasms. Long-term follow-up is crucial due to its borderline behavior and potential for local invasiveness and metastasis. Accurate diagnosis, aided by characteristic histological and immunohistochemical features, is essential for appropriate management of this rare vascular tumor.

Kaposiform hemangioendothelioma (KHE) is a rare vascular tumor of infancy that is commonly associated with a life-threatening thrombocytopenic condition, Kasabach-Merritt phenomenon (KMP). Platelet CLEC-2, tumor podoplanin interaction is considered the key mechanism of platelet clearance in these patients. Here, we aimed to assess platelet functionality in such patients. Three groups of 6 to 9 children were enrolled: group A with KHE/KMP without hematologic response (HR) to therapy; group B with KHE/KMP with HR; and group C with healthy children. Platelet functionality was assessed by continuous and end point flow cytometry, low-angle light scattering analysis (LaSca), fluorescent microscopy of blood smears, and ex vivo thrombi formation. Platelet integrin activation in response to a combination of CRP (GPVI agonist) and TRAP-6 (PAR1 agonist), as well as calcium mobilization and integrin activation in response to CRP or rhodocytin (CLEC-2 agonist) alone, were significantly diminished in groups A and B. At the same time, platelet responses to ADP with or without TRAP-6 were unaltered. Thrombi formation from collagen in parallel plate flow chambers was also noticeably decreased in groups A and B. In silico analysis of these results predicted diminished amounts of CLEC-2 on the platelet surface of patients, which was further confirmed by immunofluorescence microscopy and flow cytometry. In addition, we also noted a decrease in GPVI levels on platelets from group A. In KHE/KMP, platelet responses induced by CLEC-2 or GPVI activation are impaired because of the diminished number of receptors on the platelet surface. This impairment correlates with the severity of the disease and resolves as the patient recovers., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Angiosarcoma is an incredibly rare type of malignancy, accounting for only 1%-2% of all soft-tissue sarcomas globally. It is clinically, pathologically and radiologically difficult to diagnose angiosarcoma owing to its varied presentation with little or no well-defined imaging findings.Kasabach-Merritt syndrome is also a lesser-heard entity which carries extremely poor prognosis. It is primarily seen in infants with vascular malformations and in kaposiform haemangioendothelioma. It is a condition of consumptive coagulopathy and only few of the cases have been reported so far in the adults with a background of angiosarcoma.This report presents the case of a male in his 70s who was diagnosed with metastatic angiosarcoma and experienced a complicated disease course due to Kasabach-Merritt syndrome., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Kaposiform hemangioendothelioma (KHE) is a borderline vascular tumor between hemangioma and malignant angiosarcoma. While KHE has strong local invasion with rare spontaneous regression, it is not observed with distant metastasis. Even if KHE is asymptomatic or without the Kasabach-Merritt phenomenon (KMP), bone or joint invasion should clearly receive proactive treatment. KHE commonly affects infants/children but is rarely seen in adults., Case Report: We reported a rare adult KHE case with an invasion of >10 separate forearm/hand bones, who underwent multiple-lesion resection and finger amputation after tumor recurrence. Tumor recurrence and KMP were not observed during the 6-month follow-up after the final operation. During the hospitalization and follow-up period, the patient only received medications for infection prevention and pain relief., Conclusions: Multiple resectable lesions were found in the distal limb, for which complete resection might not present typical features (high-intensity T2-weighted MRI), which might fail to detect all KHE lesions. Therefore, complete excision is not optimal for multiple resectable KHE lesions.

Background: Composite haemangioendothelioma is a rare vascular neoplasm with indolent to intermediate malignant potential. Diagnosis of this disease relays on histopathological identification of at least two different morphologically distinctive vascular components in proper clinical settings. Exceedingly rare cases of this neoplasm can exhibit areas resembling high-grade angiosarcoma, which does not change the biological behaviour. Such lesions tend to occur in the setting of chronic lymphoedema and thus, can mimic Stewart-Treves syndrome, which has a much worse clinical outcome and prognosis., Case Presentation: We present a case of 49 years old male suffering from chronic lymphoedema of the left lower extremity who had developed a composite haemangioendothelioma with high grade angiosarcoma-like areas mimicking the Stewart-Treves syndrome. Given the multifocality of the disease, the only potentially curable surgical treatment would be hemipelvectomy, which was refused by the patient. The patient has been followed-up, with no signs of local progression of the remaining disease, nor a distant spread outside the involved extremity for two years., Conclusions: Composite haemangioendothelioma represents a rare malignant vascular tumour, with significantly more favourable biological behaviour than angiosarcoma, even in cases where angiosarcoma-like areas are present. For that reason, composite haemangioendothelioma can be easily misdiagnosed as true angiosarcoma. The rarity of this disease unfortunately hampers the development of clinical practice guidelines and the implementation of treatment recommendations. Most of the patients with localized tumour are treated by wide surgical resection, without neo- or adjuvant radiotherapy or chemotherapy. However, in the case of this diagnosis, the watch-and-wait approach is better than mutilating procedure, highlighting the necessity of establishing of the correct diagnosis., (© 2023. The Author(s).)

Background: Kaposiform hemangioendothelioma (KHE) is a locally aggressive and potentially lethal vascular tumor of infancy. Current consensus recommendations include the use of vincristine and/or systemic steroids as first-line treatment. Mammalian target of rapamycin (mTOR) inhibitors represent a promising therapy for patients with KHE. The goal of our study is to critically assess the existing literature on outcomes of patients with KHE treated with mTOR inhibitors., Methods: We conducted a literature search from 1 January 2000, to 30 April 2022. Articles reporting outcomes of patients treated with mTOR inhibitors for KHE were included. Descriptive statistics were used to describe and summarize the outcomes of the treatment., Results: We included 327 patients with a mean age at diagnosis of 9.1 months (SD ± 9). Patients were treated with an mTOR inhibitor for a mean of 15.2 months (SD ± 4.1). A total of 315 (96.3%) patients had positive outcomes including improvement of the tumor size, symptoms and/or laboratory parameters in 227 (85%) and complete remission in 38 (12%). Seven (2%) patients did not respond to treatment and seven (2%) died of sepsis (4), Kasabach-Merritt phenomenon complications (1), cardiac and liver failure due to ductus arteriosus (1), or metastatic disease (1)., Conclusion: This systematic review supports the efficacy and safety of mTOR inhibitors for KHE. Their use resulted in positive outcomes in terms of decreased symptoms, reduction in tumor size and improvement in biochemical parameters with a mortality rate of 2%. According to these findings, we suggest revised consensus treatment guidelines for KHE with mTOR inhibitors potentially considered first-line therapy., (© 2023 Wiley Periodicals LLC.)

Objectives: Pseudomyogenic hemangioendothelioma (PHE) is a rare intermediate hemangioendothelioma. This article aims to study the clinicopathological features of PHE., Methods: We collected the clinicopathological features of 10 new PHE, and examined their molecular pathological features by fluorescence in situ hybridization. In addition, we summarized and analyzed the pathological data of 189 reported cases., Results: The case group consisted of six men and four women aged 12-83 years (median: 41 years). Five instances occurred in the limbs, three in the head and neck, and two in the trunk. Tumor tissues were composed of spindle cells and round or polygonal epithelioid cells, which were either arranged in sheets or interwoven, along with areas of transitional morphology. Scattered or patchy stromal neutrophil infiltration was observed. Tumor cells had abundant cytoplasm, and some contained vacuoles. The nuclei had mild to moderate atypia, with visible nucleoli, and mitosis was rare. PHE tissues diffusely expressed CD31 and ERG, but not CD34, Desmin, SOX-10, HHV8 or S100, while some samples expressed CKpan, FLI-1 and EMA. INI-1 stain is retained. The proliferation index of Ki-67 is 10-35%. Seven samples were detected by fluorescence in situ hybridization, six of which had breakages in FosB proto-oncogene (AP-1 transcription factor subunit). Two patients experienced recurrence; however, no metastasis or death occurred., Conclusions: PHE is a rare soft tissue vascular tumor, which has biologically borderline malignant potential, local recurrence, little metastasis, and good overall survival and prognosis. Immunomarkers and molecular detection are valuable for diagnosis., (© 2023. The Author(s).)

Background: Composite hemangioendothelioma (CHE) is an intermediate group of tumors with features between hemangioma and angiosarcoma both histologically and biologically. CHE is predominant in young and middle-aged adults, but very infrequently affects the spine. We describe the case of primary CHE in the cervical spine exhibiting kaposiform hemangioendothelioma (KHE)-like components that was associated with cervical myelopathy with vertebral body destruction in an elderly woman. We retrospectively reviewed the case of a primary cervical spinal tumor, diagnosed as CHE with KHE-like components in pathological findings, associated with cervical myelopathy and cervical vertebral body destruction., Case Presentation: An 80-year-old woman presented with progressive cervical myelopathy caused by a cervical spine tumor. Preoperative cervical MRI revealed a neoplastic lesion invading the cervical spine that strongly compressed the spinal cord, causing right upper-limb paralysis. We performed partial tumor resection along with posterior decompression and fixation. Postoperatively, pathological findings showed that the tumor was CHE with KHE-like features. Following radiotherapy, no recurrences have been observed in 21 months., Conclusions: This is the first report of CHE with features of KHE in the spine of an elderly patient. Posterior decompression and fusion of the cervical spine and subsequent radiotherapy resulted in a good outcome., (© 2022. The Author(s).)

Kaposiform hemangioendothelioma is classified as a locally aggressive vascular tumor of childhood resulting from abnormal angiogenesis and lymphangiogenesis. Most commonly, KHE presents as a single tissue mass, ranging from an erythematous papule to a violaceous indurated tumor. Definitive diagnosis requires tissue sampling with the demonstration of ill-defined nodules and fascicles of spindle-shaped D2-40 positive endothelial cells, forming slit-like vascular channels. This newborn presented with multifocal cutaneous Kaposiform hemangioendothelioma associated with Kasabach-Merritt phenomenon confirmed on histopathology with immunostaining., (Copyright © 2022 by the American Academy of Pediatrics.)

Competing Interests: Conflicts of interest None disclosed.

Abstract: Intravascular papillary endothelial hyperplasia (IPEH) is a lesion characterized by the proliferation of endothelial cells within the lumen of the vessel, it was first described by Masson in 1923.The pathogenesis of Masson's tumor is still unknown, currently the most accredited hypothesis is the reactive 1. Clinically and symptomatologically it can have different presentations, it is, therefore, of fundamental importance to make a correct differential diagnosis. Diagnosis is mainly based on histological criteria. Intravascular papillary endothelial hyperplasia usually occurs in the skin and subcutaneous tissues, less commonly in the skeleton. The present is the fifth case of intravascular papillary endothelial hyperplasia of the mandible., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 by Mutaz B. Habal, MD.)

Composite hemangioendothelioma (CHE) is an extremely rare vascular neoplasm that is characterized by an admixture of benign, low-grade malignant, and malignant vascular components. It is usually located superficially in the dermis and subcutis of the extremities, and other sites involved include the head and neck region, oral mucosa, and viscera of the kidney and spleen. CHE has a low-grade malignant potential because it is locally aggressive. Here, we report a case of CHE in the heart in a 46-year-old man, who presented with a palpable mass arising from his right ventricle. Echocardiogram imaging revealed a 13.3 × 14.2 mm mass with high-signal intensity. Excision was performed, and microscopic examination revealed a heterogeneous mixture of vascular components, consisting of spindle-cell hemangioma, retiform hemangioendothelioma, and epithelioid-like hemangioendothelioma areas. To our knowledge, this is the first report on the behavior of this distinctive vascular neoplasm occurring in the right ventricle. Due to the unclear biological behavior of CHE in the heart and the paucity of cases, no further therapy was undertaken despite the risk of local recurrence and distant metastasis. The result of a six-month follow-up after surgery was disease-free.

The diagnosis of cutaneous mesenchymal neoplasms remains challenging, due to a combination of overlapping histological features, the rarity of some diagnoses and often inadequate sampling in superficial biopsies. Here, we describe recent advances in cutaneous mesenchymal neoplasms. We discuss improvements in our understanding of the molecular pathogenesis of non-neural granular cell tumour, epithelioid fibrous histiocytoma, composite and retiform haemangioendothelioma and dermatofibrosarcoma protuberans. We also discuss recently described tumour types, including some discovered via molecular testing: EWSR1::SMAD3-rearranged fibroblastic tumour, clear cell neoplasm with MITF::CREM rearrangement and melanocytoma with CRCT1::TRIM11 rearrangement, and some discovered via traditional histopathology: superficial CD34-positive fibroblastic tumour, plexiform myofibroblastoma and clear cell neoplasm with melanocytic differentiation and ACTIN::MITF translocation., (© 2021 John Wiley & Sons Ltd.)

This case report aims to present clinicopathological features of an extremely rare case of multifocal pseudomyogenic hemangioendothelioma (PMHE) in the scalp. A 21-year-old male developed multiple, focally ulcerated, nodules over the root of his nose and scalp. One of the skin lesions was sampled at another dermatology clinic, where this was diagnosed as a sarcoma. A review of biopsy sections showed well-circumscribed dermal lesions, comprising plump spindle and epithelioid cells, mimicking rhabdomyoblasts. Immunohistochemically, tumor cells were positive for AE1/AE3, CD31, FLI-1 and ERG. INI-1 was retained. A diagnosis of PMHE was offered. Subsequently, the patient underwent wide excision and has been asymptomatic for 8 months, post-surgery. PMHE is rarely reported in the head and neck region, where it can constitute a diagnostic pitfall. Awareness of this tumor and appropriate immunohistochemical stains are necessary for its timely diagnosis, in order to avoid radical treatments. A review of similar, previously documented cases is presented.

Kaposiform hemangioendothelioma is a rare neoplasm with intermediate malignant behavior, mainly affecting infants and children. Involvement head and neck is uncommon, and there are only four cases reported in the oral cavity and oropharynx. Microscopically, it is characterized by a vascular proliferation permeated by spindle-to-ovoid cells resembling Kaposi sarcoma. Immunohistochemically, the tumor is positive for CD31, CD34 and negative for D2-40. Herein we present a rare case of intraoral Kaposiform hemangioendothelioma in a 10-year-old boy., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Kaposiform hemangioendothelioma (KHE) is a rare locally aggressive mixed vascular tumor, with typical onset in early childhood and characterized by progressive angio- and lymphangiogenesis. Its etiopathogenesis and molecular bases are still unclear. Here, we report the first case of congenital KHE harboring a PIK3CA mosaic pathogenic variant (c.323G > A, p.Arg108His) in a boy with very subtle PIK3CA-related overgrowth spectrum (PROS) features. This finding provides insights into the pathophysiology of KHE, offering targeted therapeutic options by inhibition of the PI3K/Akt/mTOR pathway. We propose the inclusion of this mixed lymphatic and vascular anomaly within the PROS., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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., (© 2021. Dr. K C Chaudhuri Foundation.)

Introduction: Kaposiform hemangioendothelioma (KHE) is a rare vascular tumor of intermediate malignancy with tendency for local invasion and recurrence. The tumor almost exclusively occurs in children, especially in infants. Intracranial KHE are extremely rare with only two cases reported in the literature., Report: We report the clinical and pathological features of this rare tumor arising from basitemporal region in a 21-month child. Our case did not present with Kasabach-Merritt phenomenon. Histopathological examination confirmed the diagnosis of KHE., Conclusion: KHE should be considered in the differential diagnosis of intracranial extra-axial neoplasm in children, and histopathological examination plays an important role in distinguishing KHE from its morphologic mimics. It is essential to diagnose KHE due to its locally aggressive nature.

Purpose: The management of hepatic hemangioendothelioma (HHE) may be challenging. We aimed to review a large cohort of children who presented to our centers with symptomatic HHE in the last 16 years., Methods: We collected age at presentation, clinical features, histology, diagnostic process, management and outcome., Results: Twenty seven patients (male/female 5/22), median age 13 days (1-1530) presented with hepatomegaly (24/27), cardiac failure (10/27), cutaneous hemangiomas (8/27), fever and anemia (6/27 each), vomiting (5/27), splenomegaly (4/27). The lesion was focal, multifocal, or diffuse in 9 patients of each group. The management included medical treatment (8/27), embolization (8/27), resection (3/27), observation (6/27), transplantation (2/27). After 16 months' follow-up (30 days-11 years), 23/27 (85%) were alive. Diffuse lesions (4/4), cardiac failure (4/4), type II histology (4/4), age older than 6 months at diagnosis (3/4) predicted mortality (all p < 0.01). Histology showed type 1 lesion in 3/8, type 2 in 3/8, and type 3 in 2/8 with foci of angiosarcoma., Conclusion: Most patients with symptomatic HHE can be managed successfully with a combination of medical, radiological and surgical treatments. Patients with diffuse lesions, late presentation, cardiac failure and type II histology have a poor outcome., Level of Evidence: Diagnostic level IV. Therapeutic level IV.

Abstract: Composite hemangioendothelioma (CHE) is a rare vascular neoplasm of intermediate malignant potential. Only 52 cases have been reported in the English literature, and one case previously reported occurred in the spleen. The purpose of our study was to report a 65-year-old man diagnosed as CHE primary arising from the spleen with multiple metastases.Clinical and imaging features, laboratory tests, and pathological results about CHE were described in detail in this study.The patient presented with multiple lesions in bilateral lungs and spleen that had been incidentally detected by computed tomography (CT). Except for thrombocytopenia, other laboratory tests were not significant. The CT scan of the abdomen revealed multiple round-like and irregularly mixed density masses with unclear borders in enlarged spleen. And contrast enhancement showed mild heterogeneous enhancement. CT scan also showed widespread liver, ribs, lungs, and vertebral bodies metastases. This diagnosis was confirmed by histopathological examination. The patient underwent splenectomy and still survives with tumors after six months followed-up.Due to the lack of specificity of clinical features and laboratory tests, it is necessary to combine imaging features and pathological findings to make a correct diagnosis., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

Case Presentation: A woman in her late 40s with a history of recurrent deep vein thromboses and hypersensitivity pneumonitis (HP) presented to the ED with progressive exertional dyspnea and productive cough. She recently had started oral corticosteroids after HP was confirmed via transbronchial lung cryobiopsy from both the right upper and lower lobes, which showed poorly formed granulomas with mild interstitial and perivascular lymphocytic infiltrates. A causative antigen for her HP was never clearly identified., (Copyright © 2020 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)