To the editor: Aggressive angiomyxoma (AA) is a rare and agnogenic disease of mesenchymal origin, which usually occurs in the pelviperineal region of reproductive women. The features of the benign neoplasm are slow growth, rare metastasis and frequent local recurrences.1 Here we describe two cases diagnosed as vulvar AA in our hospital. Both of them have undergone surgical excision. We also review the relevant literature briefly.
A 50-year-old woman, G7P4, presented with a history of a painless swelling between the left labium and anus in January, 2002. It had gradually increased to the present size since nine years ago. Gynecological examination revealed a soft, relatively mobile neoplasm, with a diameter of approximately 4cm, located next to the left vaginalwall and forwarded to the anus without infiltrating the rectal wall. It was thought to be a fibrolipoma. On January 10, 2002, local excision of the mass was performed through a vulvar incision. Histology showed widely separated, spindle-shaped satellite cells lying in the abundant myxoid stroma containing scattered large arterioles with thick walls (Figure 1). A diagnosis of AA was formulated. The patient has not received any other special therapy since then. However, she suffered recurrence in 2011.
A 40-year-old woman, without history of pregnancy, presented to the outpatient department with complaint of a painless mass in the right labium majus region for more than one year on June 6, 2011. She had an excision history of bartholin cyst at the same site 6 years ago, but had no histopathology report or old medical documents. We checked up the swelling. It was about 3.5 cm large and embeded in the right labium majus with no red or heat. B-ultrasound revealed an out-of-shape cyst with inhomogeneous dense light, measured 2.9 cm×2.4 cm×2.0 cm and wrapped inside the right labium majus. On 9th June 2011, the woman underwent transperineal surgery with local excision of the mass. It was reported as AA on histopathology. The patient had hormonal treatment with tamoxifen and has no recurrence till date.
The term of Aggressive angiomyxoma is first mentioned by Steeper and Rosai in 1983,2 and it is considered to be a rare benign mesenchymal tumor with a locally aggressive nature. Most of AA arises in the female's pelvis and perineal regions. As a result of its nonspecific clinical manifestation, AA is easily misdiagnosed as vulvar cyst, vulvar abscess, lipoma, vulvar mass, Gartner cyst, Bartholin cyst, vaginal cyst before operation. In our first case, we considered it as fibrolipoma before pathology confirmation.
Generally, we confirm the diagnosis of AA through its special pathologic features. It has a homogeneously diffuse, gelatinous cut surface with focal areas of necrosis and hemorrhage at the macroscopic scale. Microscopically, diffused distribution of somewhat satellite to fusiform cells is seen in a background of loose myxoid stroma, which is rich in delicate wavy collagen fibrils. The stroma also has a prominent vascular component containing thin-walled and thick-walled vessels, but with no evidence of anastomosis or arborization.2 Our two cases meet them. Besides, both of the estrogen receptor and progesterone receptor were weak positive in the second case.
Surgery management is considered to be the first line treatment for AA. Gonadotropin-releasing hormone agonist (GnRH-a), tamoxifene alone or associated to angiographic embolization are used commonly as possible alternative means of minimizing the radicality of surgical procedure or treating recurrent tumors.3 Radiation therapy is thought to be of limited use since the mitotic index of AA is usually low.4 Both of our patients received mass excision. One suffered recurrence who had not received any adjuvant therapy since surgery. And the other, who had tamoxifene assistant therapy after operation, is free of recurrence till now. But long-term follow-up is necessary to monitor the recurrence.
1. Siassi RM, Papadopoulos T, Matzel KE. Metastasizing aggressive angiomyxoma. N Engl J Med 1999; 341: 1772.
2. Steeper TA, Rosai J. Aggressive angiomyxoma of the female pelvis and perineum. Report of nine cases of a distinctive type of gynecologic soft-tissue neoplasm. Am J Surg Pathol 1983; 7: 463-475.
3. Haldar K, Martinek IE, Kehoe S. Aggressive angiomyxoma: a case series and literature review. Eur J Surg Oncol 2010; 36: 335-339.
4. Han-Geurts IJ, van GAN, van DL, den Bakker M, Eggermont AM, Verhoef C. Aggressive angiomyxoma: multimodality treatments can avoid mutilating surgery. Eur J Surg Oncol 2006; 32: 1217-1221.