Kaposiform Hemangioendothelioma of the Spleen in an Adult: An Initial Case Report

Treatment experience for different risk groups of Kaposiform hemangioendothelioma

Background

Kaposiform hemangioendothelioma (KHE) is a rare vascular tumor with a high risk of mortality. Few studies with large samples of KHE have been reported. KHE may develop into the Kasabach-Merritt phenomenon (KMP), which is characterized by thrombocytopenia and consumptive coagulopathy. The features of severe symptomatic anemia and life-threatening low platelets make the management of KHE associated with KMP challenging.

Objective

The aim of this study was to examine the clinical characteristics of patients with KHE and discuss the treatment experience for different risk groups of KHE.

Methods

Through a retrospective review of 70 patients diagnosed with KHE between 2017 and 2022 in our center, we classify lesions into three clinicopathological stages based on the tumor involving depth, and divided the severity of KHE into three levels by estimating clinicopathological stages and severity of thrombocytopenia. Treatments of different severity groups were estimated with sufficient data.

Results

In our cohort, 27% were neonates, and KHE lesion occurred at birth in 84% of patients. There was a slight male predominance (32 girls and 38 boys). Common clinical characteristics included associated coagulation disorder (100%), locally aggressive cutaneous blue-purple mass (89%), thrombocytopenia (78%), and local pain or joint dysfunction (20%). The lower extremities were the dominant location (35%), followed by the trunk (29%), the maxillofacial region and neck (24%), and the upper extremities (10%). Of the total cohort, 78% developed KMP; the median age at which thrombocytopenia occurred was 27.8 days. The median platelet count of patients who were associated with KMP was 24,000/µL in our cohort. Ninety-two percent of patients were given surgery treatment and 89% of these patients were given high-dose methylprednisolone (5-6 mg/kg daily) before surgery. In 55 patients with KMP, 36% were sensitive to high-dose corticosteroid therapy. Patients from the low-risk group (eight cases) underwent operation, all of whom recovered without recurrence after a maximum follow-up of 5 years. Out of 26 patients from the high-risk group, 25 underwent surgery treatment, with 1 case undergoing secondary surgery after recurrence and 1 case taking sirolimus. Out of 36 cases from the extremely high-risk group, 32 underwent surgery (including 2 cases who underwent external carotid artery ligation and catheterization), 3 of whom underwent secondary operation after recurrence, and the remaining 4 cases took medicine. The mean length of having sirolimus was 21 months; two cases stopped taking sirolimus due to severe pneumonia. Two cases died at 1 and 3 months after discharge.

Conclusions

Our study describes the largest assessment of high-risk patients with KHE who have undergone an operation to date, with 5 years of follow-up to track recovery, which provides invaluable knowledge for the future treatment of patients with KHE and KMP from different risk groups: Early surgical intervention may be the most definitive treatment option for most patients with KHE; multimodality treatment is the best choice for the extremely high-risk group.

Comparison of efficacy and safety of corticosteroid and vincristine in treating kaposiform hemangioendothelioma and tufted angioma: A multicenter prospective randomized controlled clinical trial

Kaposiform haemangioendothelioma (KHE) and tufted angioma (TA) are rare vascular tumors that can cause life-threatening Kasabach-Merritt phenomenon. No evidence-based treatment strategies have yet been established, and its management is still a challenge. The purpose of this multicenter prospective randomized controlled study was to evaluate and compare the efficacy of corticosteroid and vincristine (VCR) in the treatment of KHE and TA. All patients with KHE/TA who met the diagnostic criteria were consecutively recruited. The patients were randomized into a methylprednisolone (MP) group and a VCR group. The primary outcome was the single main parameter effective rate and overall effective rate of corticosteroid and VCR over 1 month after treatment. The single main parameters included platelets, fibrinogen, tumor size, texture, and appearance. From May 2016 to April 2018, a total of 59 patients completed the clinical trial, including 29 in the MP group and 30 in the VCR group. The results showed that VCR was superior to corticosteroid in the improvement of platelet (80.0% vs 44.0%, P = 0.019) and tumor texture (68.9% vs 30.8%, P = 0.007). Although the efficacy of VCR on fibrinogen (23.3% vs 20.7%, P = 1.000), tumor size (23.3% vs 13.8%, P = 0.273), and appearance (65.5% vs 46.2%, P = 0.120) was higher than that of corticosteroid, there was no significant difference (P > 0.05). Meanwhile, the overall effective rate of VCR was higher than that of corticosteroid (56.7% vs 31.0%), but the difference was also not statistically significant (P = 0.067). In conclusion, the therapeutic effect of VCR was significantly better than that of corticosteroid with regard to treating thrombocytopenia and tumor texture. We recommend that VCR could be an option for first-line treatment in KHE/TA patients.

Vascular neoplasms and non-neoplastic vascular lesions of the spleen

Vascular neoplasms are among the most common conditions affecting the spleen. The majority of these are idiopathic, benign in nature and asymptomatic and therefore treated with a conservative management. Only rare cases cause splenomegaly and/or chronic consumption coagulopathies, thus requiring splenectomy. Among these, the most common is splenic hemangioma, followed by littoral cell angioma and lymphangioma. Peliosis is a peculiar tumor-like non-neoplastic vascular lesion that diffusely affects the spleen and frequently presents with concomitant hepatic involvement. As a distinctive feature, peliosis can occur as a secondary manifestation of infections, malignancies and in individuals using certain drugs. On the opposite spectrum of clinical behavior lies splenic angiosarcoma, a vascular endothelial malignancy with aggressive presentation and poor prognosis. In some cases the endothelial nature of this neoplasm may not be evident on routine histologic examination and immunohistochemistry is used to disclose such phenotype. The term hemangioendothelioma is rarely used to describe borderline vascular neoplasms which appear more aggressive than conventional hemangiomas, but that do not entirely fulfill the diagnostic criteria for angiosarcoma. Some of these neoplasms coexpress endothelial and histiocytic markers and therefore have been proposed as the borderline counterpart of littoral cell angioma. The existence of hemangioendothelioma as a diagnostic entity per se is debated and this diagnosis should be rendered with caution. The current review aims at highlighting the main histologic features of vascular neoplasms and non-neoplastic vascular lesions of the spleen.

Immunohistochemical Analysis of mTOR Pathway-Related Proteins in Kaposiform Hemangioendothelioma

BACKGROUND

Mammalian target of rapamycin (mTOR) inhibitors have been shown to have excellent effects in the management of kaposiform hemangioendothelioma (KHE); however, the mechanism of action is unclear. This study identified the expressions of mTOR pathway-related proteins in different vascular tumors to provide insight into the pathogenesis of KHE.

METHODS

We retrospectively reviewed the pathologic specimens of 30 patients (KHE, 15; tufted angioma [TA], 5; infantile hemangioma [IH], 5; and lymphatic malformation [LM], 5). The immunohistochemical expression of mTOR-related proteins tuberous sclerosis complex 2 (TSC2), phosphatase and tensin homologue (PTEN), phosphorylated eukaryotic translation initiation factor 4E binding protein 1 (p-4EBP1), phosphorylated mTOR (p-mTOR), and phosphorylated ribosomal protein S6 kinase B1 (p-P70S6K) were analyzed using Image-Pro Plus software. KHE had the following pattern of expression in the spindle vascular endothelial cells: TSC2 (-); PTEN (-); p-4EBP1 (+); p-mTOR (+); and p-P70S6K (+).

RESULTS

All 3 patients treated with sirolimus had good responses. The TA results were similar to KHE with no significant differences (p-4EBP1: p = 0.0687; p-mTOR: p = 0.0832). The expressions of TSC2, PTEN, p-4EBP1, p-mTOR, and p-P70S6K were negative or weakly positive in IH with a statistically significant difference compared to KHE (p-4EBP1: p < 0.001; p-mTOR: p < 0.001; p-P70S6K: p < 0.001). LM had no significant differences when compared to KHE.

CONCLUSIONS

The absence of TSC2 and PTEN caused abnormal activation of the mTOR signaling pathway and may be involved in the pathogenesis of KHE. The expression of mTOR-related proteins in TA and LM was similar to KHE, unlike IH. The KHE pattern of expression [PTEN (-), TSC2 (-), p-mTOR (+), p-P70S6K (+), and p-4EBP1 (+)] suggested that sirolimus may be a good therapeutic choice.

Clinical and imaging features of Kaposiform Hemangioendothelioma

OBJECTIVE

Kaposiform hemangioendothelioma (KHE) is a unique locally aggressive vascular tumor with poor prognosis. The aim of this study is to assess the clinical and imaging features of KHE, and to compare the differences between solitary and diffusive infiltrative subtype further.

METHODS

The clinical and radiological findings of a cohort of 25 cases with histologically proven KHE, between June 2011 and June 2016, were reviewed retrospectively. 7 solitary and 18 diffusive infiltrative subtypes KHE were included. The differences of clinical and imaging features between these two subtypes were compared statistically by Wilcoxon rank sum test and Fisher exact test.

RESULTS

The median age was 4 months old. 20 cases (80%) were accompanied by Kasabach-Merritt phenomenon (KMP). Most KHE located in trunk and/or extremity. The masses showed inhomogeneous echogenicity and were rich in vascularity on ultrasound; showed isoattenuation relative to muscle on unenhanced CT, isointense (n = 15) or slightly hyperintense (n = 7) T₁ weighted imaging (T₁WI) signal relative to muscle, mainly heterogeneous hyperintense or slightly hyperintense with speckled hypointense (n = 17) T₂WI signal (77%) relative to muscle, and notable (n = 15) and moderate (n = 3) enhancement. Feeding and draining vessels were revealed in 15 cases. Five masses with DWI showed slightly restricted diffusivity, with average apparent diffusion coefficient value of (1.28 ± 0.09) × 10^-3 mm² s^-1. Necrosis and hemorrhage were also found. Compared with solitary ones, diffusive infiltrative KHE were larger, more commonly accompanied by KMP and reticular lymphedema, and more frequently located in trunk and/or extremity.

CONCLUSION

Five masses with DWI showed slightly restricted diffusivity. A hypervascular mass accompanied by KMP and reticular lymphedema, with speckled hypointense signal T₂WI signal, especially in pediatric patients, is highly suggestive of the diagnosis of KHE. Advances in knowledge: Speckled hypointense signal T₂WI signal, and notable enhancement were unique features of KHE. KHE showed slightly restricted diffusivity on DWI, commonly accompanied by KMP and reticular lymphedema.

Kaposiform haemangioendothelioma: a review with emphasis on histological differential diagnosis

Kaposiform haemangioendothelioma (KHE) is a rare, locally aggressive/borderline vascular tumour primarily seen in neonates and children. KHE is occasionally associated with Kasabach-Merritt phenomenon and tends to have a poor clinical prognosis. While the histological features of tufted angiomas and KHE overlap, some believe tufted angiomas are a milder, benign, more localised counterpart of KHE. The other histological differential diagnoses of KHE include infantile haemangioma, congenital haemangioma, spindle cell haemangioma, verrucous malformation/haemangioma, and Kaposi sarcoma. Microscopically, KHE is characterised by confluent nodules of neoplastic spindled endothelial cells involving multiple planes of tissue which are positive for endothelial, lymphatic, and smooth muscle markers. Resection, once thought to be the definitive treatment for KHE, is often unattainable due to the extent of the lesion; thus, single or combination chemotherapies have been used to treat these patients. Sirolimus has recently been reported to be a successful agent to treat refractory and complicated cases of KHE.

Myoid Angioendothelioma of the Spleen: A Rare Case Report and Literature Review

Most common tumors of the spleen are hematologic and lymphoid malignancies. Non-lymphoid and non-hematologic tumors of the spleen are very rare, the most common of which are vascular tumors. This group of tumors in the spleen is composed of heterogeneous tumors such as hemangioma, angioendothelioma (AE), littoral cell angioma, and angiosarcoma. There are several histologic forms of AE such as epithelioid AE, Kaposiform AE, and myoid AE. Among these splenic vascular tumors, myoid angioendothelioma (MAE) seems to be the least common type. It is a distinct tumor; composed of endothelium-derived tumor cells and a special type of stromal tumor cells that seems to have borderline low-grade malignant potential. Herein, we report our experience with a young woman presented with chronic abdominal pain and splenic mass that turned out to be myoid AE of spleen with an uneventful surgery and excellent recovery period. To the best of our knowledge, such an occurrence is very rare in the spleen.

Adult-onset Kaposiform hemangioendothelioma of the tongue: case report and review of the literature

We present here a very rare clinical case of a 38-year-old man with Kaposiform hemangioendothelioma (khe) of the tongue who presented to our institution with a growth under the left side of the tongue with no pain or discomfort. There were no enlarged lymph nodes and no significant neurologic findings. Diagnostic histopathology confirmed the lesion to be khe. The tumour was removed surgically, and the surgical specimen confirmed the diagnosis. Follow-up at 3 months shows no clinical evidence of recurrence.

Response to Paclitaxel in an Adult Patient with Advanced Kaposiform Hemangioendothelioma

BACKGROUND

Kaposiform hemangioendothelioma (KHE) is a rare neoplasm of vascular origin that typically arises from the skin or soft tissues as a solitary tumor. The optimal therapy for this disease is still unknown. We report the case of an adult patient presenting with metastatic KHE of the spleen, who had a partial response after treatment with paclitaxel.

CASE PRESENTATION

A 36-year-old man presented in November 2012 with a nontraumatic rupture of the spleen. A splenectomy was performed, and the pathology was consistent with a nonspecific vascular proliferation. Follow-up scans revealed lytic bone lesions and liver metastasis. A biopsy of the liver was performed and confirmed KHE. The decision was made to proceed with treatment with gemcitabine and docetaxel, which was discontinued due to myelotoxicity. The patient was then transferred to our institution, and a pathology review supported the diagnosis of metastatic KHE. His disease remained stable until February 2014, when he developed progression in the liver. Chemotherapy was restarted with paclitaxel, and a partial response was documented after 3 cycles. Unfortunately, disease progression occurred after 24 weeks, and subsequent treatments included prednisone, doxorubicin, interferon-α, gemcitabine, and ifosfamide, without any response. The patient developed Kasabach-Merritt phenomenon and passed away 1 week later due to a major gastrointestinal bleeding.

CONCLUSIONS

This case report suggests that paclitaxel could be considered as a treatment option for advanced KHE, a rare condition for which no standard treatment exists.

Neonatal kaposiform hemangioendothelioma of the spleen associated with Kasabach-Merritt phenomenon

Kaposiform hemangioendothelioma is a rare locally aggressive vascular tumor that usually manifests during early childhood. Typically the lesion presents with skin, soft tissue and bone involvement and is characterized histologically by ill-defined nodularity and the presence of spindle cells with resemblance to Kaposi's sarcoma. We report a rare neonatal case of a splenic kaposiform hemangioendothelioma associated with Kasabach-Merritt phenomenon that was diagnosed with radiographic imaging. Because of the rapid onset of thrombocytopenia and anemia, the patient required urgent splenectomy with subsequent resolution of the blood dyscrasias.

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.

Steroid-resistant kaposiform hemangioendothelioma: a retrospective study of 37 patients treated with vincristine and long-term follow-up

BACKGROUND

Kaposiform hemangioendothelioma (KHE) with Kasabach-Merritt phenomenon (KMP) still remains a particular and life-threatening disease. The purpose of this study was to evaluate the efficacy of vincristine (VCR) and the possibility of replacement with steroids in the treatment of steroid-resistant KHE with KMP.

PROCEDURE

We retrospectively reviewed the medical records of 37 patients with steroid-resistant KHE who were treated at the Children's Hospital of Fudan University between March 2003 and March 2013.

RESULTS

The age of initial diagnosis with KHE was between 1 day and 10 months. Eight and 29 cases were located in the superficial and deep soft tissues, respectively. Thirty-seven KHE lesions did not respond well to steroids before starting VCR treatment. Twenty-six KHE lesions achieved complete remission, with platelet counts reaching normal levels within7.6 ± 5.2 weeks after VCR treatment. The vascular tumor began to decrease in size or soften at an average of 4.9 ± 2.7 weeks. Two KHE lesions had partial responses and one remains in treatment. Eight KHE lesions had no apparent response to VCR and thus received other therapies. Twenty-eight patients have ended treatment with VCR; the average length of treatment was 31.2 ± 5.9 weeks. Side effects occurred in 48.6% of patients who received steroids, and in 11.4% of patients who received VCR treatment. The mean follow-up time was 3.5 years. No recurrences have been reported.

CONCLUSIONS

VCR appears to be a safe and effective treatment option in the management of steroid-resistant KHE with KMP, and recommended as first-choice treatment.

Hemangioendothelioma arising from the spleen: A case report and literature review

Primary hemangioendotheliomas (HEs) of the spleen are rare, low-grade borderline-malignant vascular tumors. To date, only a few splenic HE cases have been reported in adults. In infants, one 9-year-old male patient has previously been reported, and the patient succumbed to the disease shortly following surgery. Currently, the clinical treatment and prognosis of the disease remains challenging to define, due to the extremely low number of cases reported. The current report presents the case of a 9-year-old pediatric patient with splenic HE, who survived with no recurrence or complications following a partial splenectomy. Additionally, a literature review was conducted to analyze the treatment and prognosis of the disease.

Intratesticular kaposiform haemangioendothelioma in adults: a report of two cases

Kaposiform haemangioendothelioma is a very rare vascular tumour of intermediate (borderline) malignancy, typically occurring in the skin and soft tissues of the extremities in infants and children. We report two morphologically and immunophenotypically classical cases occurring in the testicular parenchyma of old adults, review the literature on vascular tumours of the testis and discuss the differential diagnosis of these unusual cases.

[Kaposiform haemangioendothelioma associated with B-cell acute lymphoblastic leukemia]

BACKGROUND

Herein, we report the first case of kaposiform haemangioendothelioma (KHE) associated with acute B-lymphoblastic leukemia (B-ALL).

PATIENTS AND METHODS

A five-month-old infant presented a plaque of angiomatous appearance on the forearm that had increased in volume since birth, as well as pallor and cutaneous haematomas. Kasabach-Merritt syndrome (KMS) was evoked despite hepatomegaly and considerable splenomegaly. Laboratory tests revealed severe anaemia and thrombocytopenia as well as major hyperleukocytosis with 90% blasts. Skin biopsy revealed vast vascular lobules containing cohesive fusiform endothelial cells not expressing Glut1, bound up in a dense infiltrate of B-lymphoblast cells. It was in fact KHE associated with B-ALL confirmed by the myelogram. The child was treated with the INTERFANT 2006 protocol followed by allograft of haematopoietic stem cells, which resulted in complete haematological remission. At the same time, almost total regression of KHE was noted.

DISCUSSION

In this infant, KHE had an inflammatory appearance and was associated with thrombocytopenia, evocative of KMS. Analysis of blood and marrow samples resulted in a diagnosis of B-ALL. Histopathological examination of the angioma revealed a typical appearance of KHE associated with dense lymphoblastic proliferation. This appearance could have resulted either from passive contamination by circulating blast cells or from active recruitment of tumor cells at the KHE site.

CONCLUSION

HK mimicking KMS may reveal B-ALL.