Case 106: Aggressive Angiomyxoma

Abstract

A 46-year-old woman presented with perineal discomfort, dyspareunia, and a slowly growing mass in the perineal region. The signs and symptoms had been present for the past 6 months and had initially begun with intermittent swelling in the perineum. The patient's medical history included total abdominal hysterectomy for fibroids. The ovaries were preserved.At examination, swelling overlying the left ischial tuberosity was visible. A vaginal examination revealed a posterior mass in the left labia majorum. The mass felt cystic at palpation. Magnetic resonance (MR) imaging of the pelvis was performed.

Aggressive Angiomyxoma with Diffusion-Weighted Magnetic Resonance Imaging and Dynamic Contrast Enhancement: A Case Report and Review of the Literature

“…In that case, MRI will usually show peripheral enhancement of the wall of the cyst with variable thickness, which is totally different from the AA pattern of enhancement. The lack of macroscopic fat on CT and MRI sequences with and without fat suppression can rule out infiltrating angiolipoma and lipoma or liposarcoma with or without myxoid component [7, 8]. Endometriomas and melanomas show typical high signal intensity on T1-weighted images without signal intensity dropout on fat-suppressed images.…”

“…Classically, US without contrast injection shows a homogeneous and hypoechoic mass, sometimes cystic, that may be misleading [10]. CT scan shows an enhanced mass, which is iso- or hypoattenuating relative to muscle [7, 11]. MRI shows very characteristic aspects: an isointense tumour (more rarely hypointense) relative to muscle on T1-weighted images, and hyperintense on T2-weighted images (high water content and loose myxoid matrix) [2, 5, 7].…”

“…CT scan shows an enhanced mass, which is iso- or hypoattenuating relative to muscle [7, 11]. MRI shows very characteristic aspects: an isointense tumour (more rarely hypointense) relative to muscle on T1-weighted images, and hyperintense on T2-weighted images (high water content and loose myxoid matrix) [2, 5, 7]. The tumour enhances avidly and heterogeneously after intravenous gadolinium contrast administration, reflecting its inherent vasculature [2, 5, 7, 8].…”

“…MRI shows very characteristic aspects: an isointense tumour (more rarely hypointense) relative to muscle on T1-weighted images, and hyperintense on T2-weighted images (high water content and loose myxoid matrix) [2, 5, 7]. The tumour enhances avidly and heterogeneously after intravenous gadolinium contrast administration, reflecting its inherent vasculature [2, 5, 7, 8]. A typical MRI feature of AA is the presence of an internal layered pattern and/or swirled architecture, which is described in 83% of cases on T2-weighted MRI or on T1-weighted MRI after intravenous contrast injection [2, 5, 6, 7, 8, 9].…”

Aggressive Angiomyxoma of Vulva

“…The high signal intensity on MRI is due to the loose myxoid matrix and high water content of angiomyxoma. 7 The contrast enhancement is due to the inherent vascular nature of the tumour. This enhancement is absent in a bartholin's abscess.…”