summary Hemangioma of Soft Tissue is a benign vascular neoplasm that may be located in a cutaneous, subcutaneous, or intramuscular location. The condition is typically seen in patients < 30 years of age who present with a painful mass of variable size depending on activity level. Diagnosis is made with MRI with contrast. Treatment is usually a trial of observation, NSAIDs, vascular stockings, and activity modification. Embolization, sclerotherapy, or surgical resection are indicated for lesions associated with persistent symptoms not responsive to nonoperative management. Epidemiology Incidence males and females incidence is equal <1% of all benign vascular tumors Demographics more common in patients <30 years of age Anatomic location intramuscular is commonly found deep in the lower extremities most commonly found as isolated lesions, except for diffuse hemangioma, a rare childhood form which extensively involves a single limb common in the hand Etiology Types may be cutaneous, subcutaneous, or intramuscular capillary (superficial) or cavernous (deep) Pathophysiology caused by an error in the new formation of a segment of the vascular system hormones may play role in modulation 20% are associated with trauma Presentation Symptoms pain of variable intensity depending on activity level symptoms of vascular engorgement if hemangioma is large aching heaviness swelling Physical exam examine patient in both supine and standing position lower extremity lesions will fill up after several minutes of standing inspection mass of variable size depending on activity level Imaging Radiograph may show small phleboliths (calcifications) inside the lesion erosion into adjacent bone MRI with gadolinium differentiates these benign lesions from arteriovenous malformations and angiosarcomas increased signal on T1- and T2- weighted images focal areas of low-signal are a sign of blood flow or calcifications heterogeneous lesion with numerous small blood vessels and fatty infiltration (bag of worms) Studies Histology gross varies depending on whether it is capillary type or cavernous type color spectrum varies from red to tan to yellow micro no malignant cells noted by cellular pleomorphism noted many vascular dilations with large nuclei filled with erythrocytes vascular lumens infiltrated with muscle fibers (intramuscular type) cavernous shows large vessels with lots of fatty tissue Differential Other vascular malformations arteriovenous malformations cavernous hemangiomas angiomatosis vascular ectasia Sarcoma important to distinguish from sarcoma Treatment Nonoperative observation, NSAIDS, vascular stockings, and activity modification indications first line of treatment childhood lesions sclerotherapy or embolization performed by interventional radiology (IR) indications large, painful lesions that fail NSAID and vascular stockings therapy Operative marginal excision indications small lesions of the hand wide surgical resection indications lesions resistant to nonoperative management outcomes high incidence of local recurrence Complications Kasabach-Merritt syndrome rare complications caused by entrapped platelets leading to a possbly fatal coagulopathy Prognosis Infantile hemangiomas involute by age 7 No incidence of malignant transformation