Kaposiform Hemangioendothelioma of the Oral Cavity in an Adult Woman: A Case Report

<b>Background:</b> Kaposiform hemangioendothelioma (KHE) is a rare, locally aggressive vascular tumor that shares histological features with Kaposi's sarcoma. It usually occurs in infancy or early childhood and is seldom reported in adults. The most common sites are the skin and retroperitoneum, whereas the head, neck, and mediastinum are less frequently involved. KHE rarely regresses spontaneously, and metastasis is uncommon, but up to 70% of cases may develop Kasabach-Merritt Syndrome (KMS), a life-threatening coagulopathy. Here, we present an unusual case of KHE in an adult patient, emphasizing the importance of early recognition and management. <b>Methods:</b> A 39-year-old woman with systemic lupus erythematosus presented with an exophytic lesion in the left retromolar region. Clinical and radiological evaluations were followed by both incisional and excisional biopsies. Histopathological and immunohistochemical analyses were performed, and surgical resection with wide margins was undertaken according to recommendations from a multidisciplinary tumor board. <b>Results:</b> Histology revealed spindle cell clusters, slit-like vascular spaces, endothelial cells with eosinophilic cytoplasm, and immunopositivity for CD31, CD34, and smooth muscle actin, confirming the diagnosis of KHE. Given the tumor's locally aggressive behavior and potential risk of KMS, extended surgical excision was performed. <b>Conclusions:</b> This case underscores the diagnostic challenges of KHE in adults and highlights the essential role of histopathology, immunohistochemistry, and multidisciplinary evaluation. Prompt diagnosis and radical surgical management are critical to preventing complications and improving patient outcomes.