Identical Presentation of Scapular Osteolysis in Two Patients with Thoracic Kaposiform Hemangioendothelioma

Mediastinal Masses in Children: Radiologic-Pathologic Correlation

Most pediatric masses in the chest are located in the mediastinum. These masses are often initially detected incidentally on chest radiographs in asymptomatic children, although some patients may present with respiratory symptoms. At chest radiography, the mediastinum has been anatomically divided into anterior, middle, and posterior compartments. However, with the International Thymic Malignancy Interest Group classification scheme, which is based on cross-sectional imaging findings, the mediastinum is divided into prevascular, visceral, and paravertebral compartments. In the prevascular compartment, tumors of thymic origin, lymphomas, germ cell tumors, and vascular tumors are encountered. In the visceral compartment, lymphadenopathy and masses related to the foregut are seen. In the paravertebral compartment, neurogenic tumors are most common. Using the anatomic location in combination with knowledge of the imaging and pathologic features of pediatric mediastinal masses aids in accurate diagnosis of these masses to guide treatment and management decisions. An invited commentary by Lee and Winant is available online. ^©RSNA, 2021.

Kaposiform Hemangioendothelioma in the Thoracic Spine: A Case Report and Review of the Literature

BACKGROUND

Kaposiform hemangioendothelioma (KHE) is a rare, locally aggressive vascular tumor of childhood. It has been most commonly reported in the trunk, retroperitoneum, and extremities, but cases involving the head and neck have been described. While thought to have limited metastatic potential, it is associated with Kasabach-Merritt syndrome (KMS), a consumptive coagulopathy and profound thrombocytopenia that is associated with significant mortality. Twelve cases of KHE with bony involvement have previously been reported. Of these, only 2 involved the spine, and both were managed with medical therapy alone.

CASE PRESENTATION

We report the first case of spinal KHE causing spinal cord compression managed with surgical excision presented in the literature to date.

CONCLUSIONS

There are a number of treatment modalities outlined in the literature. The lack of a consensus is due to the varying methods of presentation, difficulty in diagnosis, and disease rarity. Our case highlights the potential speed of local growth of this tumor, meaning that excision may be a technical challenge, especially when there is epidural extension. Treating clinicians should be aware of the risk of progression beyond the initial tumor boundaries to involve new vertebrae.

Successful Management of Kaposiform Hemangioendothelioma with Long-Term Sirolimus Treatment: a Case Report and Review of the Literature

Background

Kaposiform Hemangioendothelioma (KHE) is a rare vascular tumour of the infancy and the first decade of life. It is locally aggressive and potentially life threatening when associated with consumptive coagulopathy, known as Kasabach-Merritt syndrome (KMS). No consensus or guideline for the therapy has been reached because of the lack of prospective trials, and the different standard care suggestions are based on retrospective case series.

Case report

We report the case of a 9-month-old male with KHE and KMS in which the initial response, obtained with prednisone and vincristine, was subsequently consolidated and strengthened by long-term treatment with sirolimus, a mTOR inhibitor. A summary of the published data is presented as well.

Conclusions

The inhibition of mTOR pathway represents the most important therapeutic innovation introduced in the last few years for KHE. Our case shows the effectiveness and good tolerance of long-term therapy with sirolimus.