Vulvar lipomas are unusual and giant vulvar lipomas are extremely rare . Vulvar lipomas are rare benign mesenchymal tumors consisting of mature fat cells, often interspersed with strands of fibrous connective tissue . They usually present as slow growing, painless, and mobile soft tissue . Vulvar lipomas must be differentiated from Bartholin’s cyst, Nuck canal cyst, inguinal hernia, and liposarcoma .
When the clinical diagnosis is not apparent, radiologic techniques, US, computed tomography, and MRI, are useful in differentiating vulvar lipomas [1, 5, 6]. Ultrasound can be helpful to differentiate the cyst, omentum, and intestine tissue [1, 5, 6]. In our case, first, we aimed to differentiate cystic and solid component by ultrasonography. A pure, homogeneous solid component with no cystic component was detected on US. There was no sign of inguinal hernia on clinical examination, so Nuck canal cyst, Bartholin’s cyst, and inguinal hernia were not considered in pre-diagnosis.
It is also important for the radiologist to preoperative diagnosis, especially to demonstrate difference between the lipoma and well-differentiated liposarcoma, because simple lipomas are often successfully treated with local excision. Well-differentiated liposarcomas are preferentially treated with wide local excision because of their risk of local recurrence [2, 7, 8]. Gaskin CM et al. showed that MRI has 100% specificity to diagnosis lipoma and 100% sensitivity to diagnosis well-differentiated liposarcomas . Both of them are gross fatty masses, but their prognosis and treatment are not the same. MRI has been described as a useful radiologic method for obtaining the correct diagnosis. Simple lipomas are homogeneous fatty masses; but rarely a non-adiposis component will show up on MRI. Well-differentiated liposarcomas often include thickened or nodular septa, prominent foci of high T2 signal, and prominent areas of enhancement. These finding are associated with non-adipose components [2, 7, 8]. Higher-grade liposarcomas generally do not alter the MRI diagnosis of gross fatty lesions because they typically contain little or no macroscopic fat . In our case, there was a homogeneously fatty vulvar mass without diffusion restriction and contrast enhancement on MRI. These radiological findings supported the diagnosis of lipoma.
Also, simple lipomas may sometimes contain muscle fibers, blood vessels, fibrous septa, and areas of necrosis and inflammation. Due to these contents, they can mimic findings associated with well-differentiated liposarcomas and rarely liposarcoma . Similarly, in our case, there were a few non-adipose areas on MRI.
Clinical information and MRI findings provide helpful information to diagnose lipomas and differentiate from other pathology. Surgical excision is the best treatment for vulvar lipomas, as it allows for exclusion of any malignant components after histopathological examination .