Angiomyofibroblastoma of the Vulva

Author information

Asmita Patil*, Parulekar SV**, Samant PY***, Gwendolyn Fernandes****
(*Senior Resident, **Professor and head of the department, *** Additional Professor Department of Obstetrics and Gynecology, **** Associate Professor, Department of Pathology, Seth GS Medical College and KEM Hospital, Mumbai, India.)

Abstract

Angiomyofibroblastoma is an uncommon, benign, nonrecurring, mesenchymal,  myofibroblastic tumor that occurs most commonly in the vulva and vagina.  It  usually occurs in premenopausal women. We report a case of angiomyofibroblastoma  of the vulva occurring in a 38 year old woman in the paraurethral region.

Introduction

Angiomyofibroblastoma  is a rare benign mesenchymal tumor that is commonly observed  in the vulvovaginal region of women.[1-3]  It is a slowly growing tumor which is often misdiagnosed as a Bartholin’s cyst, a lipoma, cellular angiofibroma, fibroepithelial stromal polyp, superficial angiomyxoma or a perineal hernia.[4] Histologically, the tumor is a well-circumscribed lesion composed of alternating hypo- and hypercellular areas with numerous delicate capillary-sized vessels, the presence of plump stromal cells, and perivascular condensation of the stromal cells.[5-9]  Majority of the reported cases shown that the mass arises from labia majora but our in our case the  mass was arising from paraurethral region.

Case Report

A 38 year old multiparous woman came to our outpatient department with a history of a mass at the vulvar region.The mass had gradually grown in size over eight years. There was no dyspareunia. There had been no history of pain in the swelling at any time, fever, periodic changes in the size of the swelling or its rupture at any time. She had dysuria for 2 months. On local examination 3X 3 cm soft swelling was present just lateral and a little superior to the external urethral meatus on left side. It appeared cystic. It was freely mobile under the epithelium, and moved independent of the urethra. General, systemic, per speculum and bimanual pelvic examination showed no abnormality. Urinalysis showed 10-15 pus cells per high power field. Microbiologic study of urine showed E. coli sensitive to nitrofurantoin. She was treated for that and got well. Her hemogram, blood sugars (fasting and postprandial), liver function tests, renal function tests, chest radiograph and elelctrocardiogram results were within normal limits. A urological reference was made. The urologist confirmed that the mass was not connected with the urinary bladder or urethra.
A No. 14 Foley's catheter was passed into the urinary bladder through the urethra. The mass was excised under general anesthesia, through a longitudinal incision placed over the most prominent part of the mass, medial to the left labium minus, lateral and a little superior to the external urethral meatus. It appeared encapsulated and could be dissected easily without any significant blood loss. Redundant part of the overlying epithelium was excised and the edges were sutured with interrupted sutures of No. 2-0 polyglactin. The catheter was removed after 24 hours. The patient made an uneventful recovery. She had no difficulty in micturition postoperatively.
Microscopically the section of the mass showed a circumscribed mass with a vascular structure partly enveloping it. The lesion was composed of prominent vascular channels surrounded by plump spindle shaped cells and thick bundles of collagen. Individual plump spindle shaped cells showed prominent oval to spindle shaped nuclei and abundant eosinophilic cytoplasm. A diagnosis of vulvar angiomyofibroblastoma was made.


Figure 1. Swelling of the vulva, on the left side of the external urinary meatus.


Figure 2. The tumor in its bed, after incision in the epithelium above it and dissection of the epithelial flaps.


Figure 3. Thinly encapsulated  tumor with hypercellular and hypocellular areas. Slit-like spaces seen represent capillary size vessels. (H & E x 100).


Figure 4. Tumor composed of plump spindled to oval  cells and capillaries  amidst thin wavy strands or thick bundles of collagen. (H & E x 400).


Figure 5. Spindle cells show strong positivity for desmin.


Figure 6. Strong positivity for smooth muscle actin.

Discussion

Angiomyofibroblastoma is a rare benign mesenchymal tumor that is commonly observed  in the vulvovaginal region of women.[1-3] It was first described by Fletcher et al in 1992. [10] It is a slowly growing mass which is often misdiagnosed as a Bartholin’s cyst, a lipoma, cellular angiofibroma, fibroepithelial stromal polyp, superficial angiomyxoma or a perineal hernia.[4] Grossly it is a well circumscribed but usually nonencapsulated, soft lesion measuring 1-10 cm (mean 4 cm) in diameter. Its cut section of the lesion is gray–pink with a glistening appearance. Microscopy shows a pseudocapsule, small-medium sized, well-formed vessels, round to spindled myofibroblasts placed around the vessels, alternating hypercellular stromal area and hypocellular edematous area, spindle- or epitheloid-shaped stromal cells gathered around abundant capillary-type blood vessels and loose edematous stroma in varying proportions. The tumor cells have bland nuclei and eosinophilic cytoplasm epithelioid to plasmacytoid neoplastic cells, binucleate or multinucleate cells, interstitial mast cells, and mature adipocytes. Mitotic figures are rare, tumor necrosis absent. Longstanding lesions show fibrosis and perivascular hyalinization.[4-9]
It may be mistaken for an aggressive angiomyxoma, which shows abundant myxoid matrix, infiltration of surrounding tissue, unclear border, low cellularity, thickened medium-to-large sized vessels, and extravasation of red blood cells.[6,7,8,9] A cellular angiofibroma (CA) may be mistaken for an angiomyofibroblastoma too. Both of them have prominent vascular components, bland stromal cells, and adipocytes. Angiomyofibroblastoma is distinguished from CA by the presence of round tumor cells grouped around vessels, and a lack of wispy collagen bundles and numerous thick-walled, hyalinized vessels.
It is a benign nonrecurring lesions and simple excision is curative. A recurrence is rare. Still a long term follow up is recommended.

References

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Citation

Patil A, Parulekar SV, Samant PY, Fernandes G. Angiomyofibroblastoma of the Vulva. JPGO 2014 Volume 1 Number 7 Available from: http://www.jpgo.org/2014/07/angiomyofibroblastoma-of-vulva.html