Aggressive angiomyxoma (AAM), a rare soft tissue neoplasm, predominantly occurs in the female pelvic peritoneum and perineum region. These lesions are distinguished by their slow growth and frequent recurrences, and are characterized histologically by a predominantly myxoid stroma and abundant thin- and thick-walled vascular channels. Because of its rarity, AAM is often initially misdiagnosed as a gynecological malignancy. We also found that AAM looked like lava expulsion in the pelvic cavity. After a thorough examination and full radiologic workup, we performed surgical excision, using a different surgical approach for each growth site.

AAM is a slow-growing mesenchymal neoplasm with a high local recurrence rate, but with a low tendency to metastasis. It was first described as a distinct variant of myxoid neoplasms in 1983 [1]. These tumors mostly occurs in the 4th decade of life and 95% of them occur in women [2]. It typically presents as a vulvar polypoid mass, and diagnosed using histology. The tumors are sometimes positive for estrogen and progesterone receptors [1]. They are thus likely to grow during pregnancy and respond to hormonal management [3]. AAM occurs mainly in the pelvis, perineum, vulva, vagina, and urinary bladder, and may exert pressure on adjacent organs. Appropriate management and long-term follow-up of this tumor should be considered owing to its locally aggressive nature [4]. This tumor also involves the blood vessels. It can affect the vulva [5] and other parts of the pelvis [6]. This disease has locally infiltrative and recurrent characters. It presents as a painless gelatinous mass and can simulate Bartholin gland cyst or inguinal hernia-like symptoms. Many options have been used for treating recurrences, with varying success, and no single modality is clearly more beneficial than others [1]. Although it is a benign tumor and does not invade the neighboring tissue, it has a tendency to recur after surgical excision [2]. Recurrence can occur at same site after the initial resection [7]. The incidence of local recurrence after surgery is 36% to 72%. The recurrence rate in patients with narrow surgical margins is not higher than in patients with wide surgical margins. The reported age at presentation is 6 to 77 years, with peak occurring incidence during the reproductive years. The female-to-male ratio is 6.6/1. AAM should be distinguished from benign tumors with a low risk of local recurrence as well as from malignant tumors with widespread metastatic potential.

AAM has a characteristic appearance on CT and MRI, and these techniques reveal the tumor extent. On CT, the tumor has a well-defined margin and attenuation less than that of muscles. On T2-weighted MRI, the tumor has high signal intensity [8]. After diagnosis, preoperative angiographic embolization and preoperative external beam irradiation can be helpful to decrease local recurrence [9].

On gross examination, these tumors are typically soft, bulky masses [7]. The external surface is smooth and usually appears not to be encapsulated. Some have projections resembling fingers that extend into neighboring tissues. The cut surface reveals a grey tumor of homogeneous consistency with focal areas of congestion and hemorrhage. Histologically, AAM are mesenchymal tumors, composed of fibroblasts within a strong myxoid background. The tumor consists of scattered hypo-cellular and fusiform cells with thin cytoplasmic processes in a loose myxoid matrix that gives the tumor a pale-pink color on eosin staining. The tumor has also a prominent vascular component with distinct smooth muscle cells without anastomosis. Mitosis is usually not observed, and occasional cases may show mild atypia. Immunohistochemical staining of the tumor for desmin, vimentin, CD34, CD44, S100, smooth-muscle actin, and muscle-specific actin are necessary for the diagnosis [71011]. The term AAM was chosen to emphasize the neoplastic nature of the blood vessels, its locally infiltrative nature and the high risk of local recurrence, but not to indicate its malignant nature [7]. The pathogenesis of AAM is poorly understood. Non-random involvement of the 12q15 region, where the high mobility group protein HMGA2 (an architectural transcription factor expressed primarily during embryogenesis) is located, has been suggested [10]. AAM resection is sometimes difficult because of its infiltrative nature, and recurrence occurs in 70% of cases, but even patients with clear resection margins can develop recurrence [3]. Nonetheless, excision with wide tumor-free margins is still the most common treatment [3]. Incomplete resection is acceptable when high operative morbidity is anticipated or preservation of fertility is an issue [57]. Possible alternative treatment methods for recurrences are gonadotrophin-releasing hormone (GnRH) agonist or antihormonal therapy (tamoxifen) [711]. Several beneficial results have been described using a GnRH agonist [12]. However, long-term GnRH agonist therapy is associated with adverse effects such as menopausal symptoms and bone loss. Potential disadvantages are that the tumor will become resistant to GnRH agonist therapy, and medication withdrawal may result in neoplasm regrowth [7121314]. The optimal duration of therapy is not known, but long term GnRH agonist therapy is not recommendable because of its potential adverse effects [12]. Chemotherapy and radiation therapy are not considered owing to low mitotic activity of the tumor [7]. For estrogen receptor and/or progesterone receptor positive tumors, hormone treatment is a good option. Long-term follow-up and careful monitoring with imaging techniques are essential for timely identification of recurrence [10]. In conclusion, AAM is a rare mesenchymal benign tumor that occurs primarily in the vulvar, vaginal, perineal, and pelvic soft tissues in women of reproductive age. The tumor grows slowly but infiltrates into the softer pelvic spaces in a way similar to lava expulsion from a volcano. Awareness of this disease and full radiologic workup is necessary for surgical planning and recurrence monitoring.