Rare case of angiofibroma presenting as perineal hernia

Background

Nucci et al first described cellular angiofibroma in 1997 in a series of six female patients.1 The most common site of origin in women is the vulvovaginal region, and in men is the inguinoscrotal area. There is no sex predominance.2 Tumour size may vary from 0.6 to 25 cm.3 Most commonly, it presents either as a Bartholin’s cyst (48%), solid mass (28%), vulval cyst (12%) or lipoma. However, no case reports of angiofibroma presenting as perineal herniation has been reported. Though, a few case series of aggressive angiomyxoma as perineal herniation have been reported. Differential diagnoses of these tumours include many aggressively growing tumours, such as aggressive angiomyxoma and soft tissue sarcoma, which have a very high recurrence rate and have to be differentiated by immunohistochemistry.2 Treatment includes simple excision of the tumour to avoid recurrence in the future.3

Case presentation

A 31-year-old woman presented with swelling in the right gluteal region for the past 9 months associated with mild pain and discomfort on sitting. Swelling was reducible in nature, with no history of constipation, obstipation and abdominal distension. No history of urinary and gynaecological symptoms, and no history of surgery or admission in hospital.

On examination, a 15×10 cm firm, non-tender reducible swelling was present in the right gluteal region with normal overlying skin. Cough impulse was present. The patient was admitted a few months after the outpatient department visit, and on the day of admission, the swelling was irreducible with visible dilated veins over the swelling (figure 1). The per-abdomen examination was normal. Per-rectal examination revealed an extraluminal lump palpable on the right side.

Figure 1

Preoperative pictures of the tumour.

Investigations

She underwent an ultrasound, which reported a 14×6 cm elongated heteroechoic reducible structure herniating into the right gluteal region with a bulky uterus lying inferiorly, likely uterine prolapse. Doppler ultrasound demonstrated multiple venous channels with a flow velocity of 6–10 cm/s within the core of the tumour, suggestive of a vascular soft tissue lesion. Following ultrasound, contrast-enhanced MRI was performed, which reported a well-encapsulated area of size 8.7×14.5×24.2 cm with altered intensity on the right side of the pelvis. Heterogeneously isointense on T1 and hyperintense on T2 with heterogeneous post-contrast enhancement and few linear whirled hypointense foci. The mass was extending from the right adnexa into the perineal region, up to the right gluteal region. The mass was abutting the urinary bladder anteromedially, and uterus and rectum posteriorly, and was extending posteriorly to the presacral space. Laterally, it was abutting the lateral pelvic wall and the medial part of the right gluteus muscle. Fat planes were well maintained with the adjacent structure without any infiltration (figure 2). With the above-mentioned clinical assessment and radiological workup, a provisional diagnosis of irreducible perineal soft tissue tumour, probably an aggressive angiomyxoma, was kept as a provisional diagnosis. Further CT imaging of the chest and abdomen was performed for soft tissue tumour staging, which was normal.

Figure 2

MRI showingT2 hyperintense mass extending from the pelvis to the perineum through the levator ani. Post-contrast images showing a characteristic layered pattern or swirled appearance.

Treatment

She was laid in a modified lithotomy position and we approached the tumour both from the abdominal and perineal area as it was an irreducible, large tumour and complete excision required a good exposure. On exploration, a bulging mass was present in the retroperitoneal region of the right iliac fossa, which was lateral to the urinary bladder and extending downward into the pelvis and reaching up to the perineum through the pelvic inlet. The mass was soft in consistency and well-encapsulated. It was mobilised circumferentially inferiorly until the pelvis. The perineal approach with an inverted Y-shaped incision was made over the swelling. The 20×8×3.5 cm tubular mass was mobilised along with the capsule superiorly and was delivered out through the perineal incision (figure 3). Uterus, bilateral ovaries, urinary bladder and rectum were normal and not involved by the tumour. A perineal closed suction drain was placed and the skin was closed.

Figure 3

Postoperative picture of the tumour measuring 20×8×3.5 cm.

Histopathology reported a 17×16×7.3 cm size well-circumscribed benign tumour with no capsular breach. It was composed of an intricate mixture of stellate and staghorn blood vessels of various sizes in the fibrous stroma, which showed oedema and myxoid changes (figure 4). No atypia or increased mitosis was seen. Overall, the features were suggestive of angiofibroma. Immunohistochemistry of the tumour showed oestrogen receptor positivity with a Ki67 index of 3%.

Figure 4

Histopathology reported a 17×16×7.3 cm size well-circumscribed benign tumour with no capsular breach and composed of an intricate mixture of stellate and AMP; staghorn blood vessels of various sizes in the fibrous stroma which shows oedema and myxoid changes.

Outcome and follow-up

The patient did well after the surgery and is currently in follow-up. No adjuvant treatment is required. We have scheduled her for a 3-month follow-up for 1 year with clinical examination, and planned for contrast-enhanced CT of the abdomen/MRI of the abdomen at 6 months.