Pitfalls in Ultrasound Diagnosis of Vascular Malformations: A Retrospective Review of 14 Nonvascular Tumors Treated as Vascular Malformations.

Abstract

Background/Objectives: Vascular malformations form masses in subcutaneous and muscular tissues throughout the body and are occasionally misdiagnosed as subcutaneous nonvascular tumors. Understanding and differentiating their clinical and imaging features are crucial due to their different treatments and prognoses. This study aimed to report cases of nonvascular tumors that were initially misdiagnosed and treated as vascular malformations. Methods: In this retrospective observational study, we enrolled 14 (1.8%) patients with pathologically diagnosed nonvascular tumors from among 536 patients with 759 lesions of clinically diagnosed vascular malformations. Results: The average age at the initial visit was 41.9 years, with a male-to-female ratio of 3:11. Tumor locations included the lower limb in seven patients, the upper limb in five patients, and the trunk and head in one patient each. Ultrasound evaluation revealed 12 lesions of low-flow vascular malformations and two lesions of high-flow vascular malformations. These findings led to an initial diagnosis of venous or lymphatic malformations in 12 patients and arteriovenous malformations in two patients. Based on the clinical diagnosis, treatments administered before tumor resection included sclerotherapy in four patients and transcatheter arterial embolization in one patient. All patients underwent tumor resection. The final histopathological diagnoses included schwannoma in six patients, epidermal cyst and angiomyoma in two patients each, and other types of tumors in four patients. The average time from initial diagnosis to final histopathological diagnosis was 370 days. Conclusions: Multimodal diagnostic strategies, especially the use of ultrasound, enhance the differentiation between vascular malformations and nonvascular tumors.