Radiographic diagnosis and differentiation of an aggressive angiomyxoma in a male patient

Abstract

Aggressive angiomyxoma is a rare soft-tissue tumor which usually occurs in female patients of reproductive age. Its occurrence in men is even more unusual and as illustrated in this case the difference between pathology suggested by a physical examination and its actual extent can be quite striking. We present a case report of an 81-year-old man with the typical MRI appearances of a pelvic aggressive angiomyxoma, describe imaging and histopathologic features of this rarely seen locally infiltrative neoplasm and also discuss therapeutic options for patients with an aggressive angiomyxoma.

Keywords: MRI; abdominal imaging; aggressive angiomyxoma; histology; imaging; therapy; tumor.

Figure 1

81-year-old male with an aggressive angiomyxoma. FINDINGS: heterogeneous, hyperintense pelvic mass (white arrowheads, 15 × 5 cm) with a cystic component at the upper aspect (black star). The mass extends both superiorly and inferiorly relative to the levator ani muscle (curved white arrows). The internal architecture is composed of hypointense layered strands. TECHNIQUE: Coronal fast spin-echo T2-weighted fat-saturated MR image (repetition time msec/echo time msec, 4472/60, 3 Tesla)

Figure 2

81-year-old male with an aggressive angiomyxoma. FINDINGS: Well-defined mass (black arrowheads, 5 × 7,5 cm) situated centrally in the pelvis and anteriorly to the rectum (black arrow). The signal intensity is isointense to that of muscle. TECHNIQUE: Axial T1-weighted spin-echo (713/9, 3 Tesla) MR image

Figure 3

81-year-old male with an aggressive angiomyxoma. FINDINGS: Image obtained at the same level as in Figure 2 demonstrates a heterogeneously enhancing mass (black arrowheads, 7,5 × 5 cm). Swirled strands of tissue (black arrow) appear less enhanced in the mass center. TECHNIQUE: Axial fat-supressed T1-weighted spin-echo (666/9, 3 Tesla) delayed post-contrast MR

Figure 4

81-year-old male with an aggressive angiomyxoma. FINDINGS: Image demonstrates the multidirectional extension of the mass (black arrowheads) relative to the pelvic diaphragm. The mass lies anteriorly to the rectum (open white arrow) and involves the perineum dorsally and anteriorly (black arrows, 4 × 3,5 cm and 4 × 4 cm respectively). Cystic changes can be seen in the upper part of the mass (black star, 4,5 × 5,5 cm). TECHNIQUE: Sagittal fast spin-echo T2-weighted MR image (4721/90, 3 Tesla)

Figure 5

81-year-old male with an aggressive angiomyxoma. Histologically, the tumor shows a monotonous fibrous stroma with bland spindle cells and abundant vascular channels. The centrally located vessels demonstrate a prominent muscular wall (HE, 200x)

Figure 6

81-year-old male with an aggressive angiomyxoma. In greater magnification the spindle cells show monomorphic nuclei with prominent nucleoli. Mitotic figures are absent. The vessels shown here lack a muscular wall and have a capillary phenotype (HE, 400x)

Figure 7

81-year-old male with an aggressive angiomyxoma. FINDINGS: About 2 years after R2 resection imaging shows stable findings - some residual cystic lesions are still present (black triangle, ca, 2–3 cm in diameter) but the main tumor mass has been removed and shows no signs of recurrence. The urinary bladder is marked by a black star. TECHNIQUE: Coronal fast spin-echo T2-weighted fat-saturated MR image (1600/100, 3 Tesla).