Clinical History
A 49-year-old female presented with undetermined hypogastric pain and slight vaginal discomfort. A transvaginal sonography was performed and a solid-cystic lesion (50x35x36mm) in contact with the anterior vaginal wall revealed. No other relevant findings or significant previous medical procedures were known.
Imaging Findings
- MRI:
A well-defined solid tumour was located in the paravaginal and parametrial right area (Fig.1).
The tumour was hyperintense and heterogeneous on T2 weighted sequences (Fig.1), observing multiple hypointense strands (Fig.2a) within it (swirled appearance). After contrast injection, the lesion showed a progressive and heterogeneous enhancement (Fig.3).
It displaced the vagina towards the left side but without invading its wall (Fig.2a).
Inferiorly, the lesion had a finger-like projection which infiltrates the right puborectal muscle reaching the ischio-anal fossa (Fig.2b), clearly in contact with the internal obturator muscle (Fig.2c).
MR report should include precise anatomical description for a complete resection when describing these tumours.
Discussion
INTRODUCTION [1]
Aggressive angiomyxoma is a slowly growing mesenchymal tumour.
It affects women of reproductive age and usually involves the deep soft tissues of the vulvovaginal region, pelvis and perineum of women as well as the inguinoscrotal region in men (less likely).
Metastases are extremely rare (lungs mainly).
This tumour is considered aggressive because of the high rate of local recurrence.
IMAGING FINDINGS [2, 3]
Transvaginal sonography (US):
There is no specific feature, the key findings are:
- Localisation (usually paravaginal, paravervical or pelvic)
- Tubular/fusiform morphology
- Lipoma-like appearance
- Doppler: Internal vascularization
CT findings:
- A mass hypodense or isodense to muscle
- Well-defined margins
- Variable contrast enhancement
MRI findings:
- High signal intensity on T2WI (myxoid stroma)
- Swirled/laminated appearance: hypointense strands of fibrovascular tissue.
- Finger-like projections
- Contrast enhanced sequences: progressive and heterogeneous enhancement.
- Mild restriction on DWI with characteristic high mean values in ADC maps.
- MR report should include precise anatomical description (relationship with the vagina, urethra, anal sphincter, rectum or extension above/below pelvic diaphragm) when describing these tumours. MR report must include a description of the relationship between the mass and the pelvic diafragm.
TREATMENT [2]
- Wide surgical resection (complete excision) is the treatment of choice. Incomplete resection is considered acceptable if followed by long-term follow-up.
- Most of these tumours show oestrogen and progesterone receptor positivity. Hormonal treatment is thought to be a viable treatment as well as an interesting option for pre-operative shrinking of these tumours.
- High rate of local recurrence in the first years after surgery (more than 35% of patients).
- Radiotherapy or chemotherapy is unlikely to be useful (low mitotic activity).
- Angiographic embolisation success is limited by the presence of multiple feeding vessels instead of having just one large feeding vessel.
Differential Diagnosis List
Aggressive angiomyxoma
Myxoma
Myxoid lipoma
Myxoid liposarcoma
Myxoid leiomioma
