Superficial myofibroblastoma of the lower female genital tract with description of the MRI features

Abstract

Superficial myofibroblastomas of the lower female genital tract are an unusual type of benign mesenchymal tumour. To the authors' knowledge, there has been no previous imaging description of a superficial myofibroblastoma in the literature. Here, we describe a case that presented with symptoms consistent with vaginal prolapse. However, a mass was palpable on clinical examination with unusual features on MRI. Following surgery, the histopathological features were considered consistent with superficial myofibroblastoma. By presenting the MRI and histological findings, we aim to raise awareness about this lesion so that it may be considered in the differential diagnosis of a vaginal mass.

Figure 1.

T₁ weighted axial section of the pelvis. The well-circumscribed rounded mass in the region of the upper vagina demonstrates intermediate T₁ signal.

Figure 2.

T₂ weighted axial section of the pelvis with a small field of view. The well-circumscribed rounded mass in the region of the upper vagina demonstrates heterogeneous T₂ signal. Loss of left posterolateral outer vaginal margin and signal change in the left paravaginal fat was noted.

Figure 3.

T₂ weighted sagittal section of the pelvis. Discrete zones of low and high signal are demonstrated within the lesion. The mass appears to be arising within the posterior vaginal wall with displacement of the vaginal lumen anteriorly.

Figure 4.

Sagittal T₁  weighted image with fat saturation and gadolinium contrast enhancement. The area of low T₂ signal noted within the lesion in figure 3 demonstrates avid contrast enhancement and corresponds histologically to a hypercellular area with high collagen content. The high T₂ signal area does not enhance and corresponds to paucicellular myxoid tissue.

Figure 5.

Axial portal venous phase contrast-enhanced CT image of the upper vagina demonstrating a mixed attenuation mass with patchy avid contrast enhancement.

Figure 6.

Haematoxylin and eosin preparation of the vaginal mass on a large block mount with ×2 magnification. The deep pink hypercellular area contains spindle cells set in dense collagen, whereas the paler area reflects an area of myxoid change with few cells. This correlates precisely with the appearances in Figures 3 and 4.