Srinivasan N*, Panchbudhe S**
(* Junior Resident, ** Assistant Professor, Department of Obstetrics & Gynecology, Seth G S Medical College and K E M Hospital, Mumbai, India.)
Fibroepithelial polyps are mesenchymal lesions that are site specific and usually found in the vulvovaginal area of females in their late reproductive ages. These tumors are usually small and are seen only during routine gynecological examination. Although the tumor is benign, it closely resembles some malignant vulvar lesions, therefore accurate histopathologic diagnosis is required. We present a case of a 24 year old female with a giant fibroepithelial stromal polyp of the vulva.
Fibroepithelial polyps are site specific mesenchymal lesions that are and usually found in the vulvovaginal area of females in their late reproductive ages. They are mostly found in the vagina and rarely they are found in extra-genital sites. These are hormone sensitive tumors, they are most commonly seen in pregnancy and grow larger in size in pregnancy. They are also seen in pre-menopausal females on hormone replacement therapy. Typically these lesions do not grow large and are discovered during routine gynecologic examination. These tumors can have varied appearance, can be sessile, pedunculated, or polypoidal. Patients may present with complaints of bleeding, discharge and general discomfort over the area.
A 24 year old nulliparus female; married since 6 months, admitted with complaints of a mass that had been growing on her left labium. Following a brief physical examination, verification was made of a left labial mass. She first noticed a marble-sized “bump” on her left labium about six months earlier. The mass gradually increased in size over last six months until its current size on presentation. She was on second day of her cycle and had no complaint of nausea, vomiting or other constitutional symptoms. There was no significant medical or surgical history. She had no history of any sexually transmitted diseases or gynecological surgery. She had regular menstrual cycles, 30 days cycle intervals and 4 to 6 day cycle lengths with moderate flow. She was sexually active since last 6 months, and complained of pain, dyspareunia at entry. She had no history of usage of any contraceptives or hormonal pills.
Her physical exam was remarkable only for a 5-6 cm, non-tender, lemon-sized, ulcerating pedunculated mass (red arrow) extending from the lower end of the left labium majus. On touch, lesion appeared solid but soft in consistency and was compressible upon application of gentle pressure. The mass was free from all sides, and had a 2-3 cm thick pedicle (blue arrow) that connected the mass with the lower edge of the left labium majus. The stalk was vascular with an ulcer over the serosal surface of the polyp. There was no change in the size of the mass with Valsalva maneuver.
Transvaginal ultrasound showed normal anatomy of the uterus and ovaries but also described a broad-based encapsulated soft tissue mass arising from the left labium at its lower end. Her all routine investigations were within normal limits and she was tested seronegative for HIV/ HbsAg/ Ani-HCV/ RPR. She was posted for labial mass excision under short general anesthesia after taking written, valid and informed consent from her and her relatives. Intra-operative photography consent was also obtained. Semilunar incisions were placed on anterior and posterior aspects of the pedicle, joined with each other and deepened until the pedicle was cut off, separating the mass from the labium. Hemostasis is achieved with polyglactin no. 1 simple interrupted sutures placed over the labial muscle bed (Green arrow) and skin was approximated with No. 2-0 monofilament nylon vertical mattress sutures. She tolerated the procedure and anesthesia well. The pathology report suggested fibroepithelial stromal polyp and she was advised to return to her routine gynecology check up for continued surveillance.
The labial mass was globular, pedunculated, soft in consistency, measuring 5.0x3.5x2.0 cm On cutting opening the specimen, whitish pink glistening surface was seen (orange arrow). Skin over the stalk was dark brown in color, wrinkled and showed healed ulcers. Skin on the mass proper was pale and showed ulcers in various stages of healing with absence of myxoid areas. Microscopic evaluation of the lesion in our case revealed polypoidal lesion lined by keratinized stratified squamous epithelium. Focally, it was ulcerated and replaced by fibrino-suppurative exudates. Sub-epithelial tissue showed dense collagenization, mixed inflammation and ectatic blood vessels while deeper tissue was loose and showed scattered spindle and few stellate cells. Blood vessels of various calibre were also seen with few blood vessels thickened and dense lympho-plasmacytic infiltrate were seen along with perivascular inflammation suggestive of Fibro-epithelial polyp of the vulva.
Fibro-epithelial polyps of the vulva have different sizes and appearance. The margins of these tumors coalesce with healthy tissue and are thick-walled with a central core. Malignancy should be excluded in every diagnosis of fibroepithelial vulval polyp. Sarcomas have similar characteristics like that of fibroepithelial polyp and to differentiate between them, microscopic examination is essential for final diagnosis.
The most characteristic microscopic feature of a fibroepithelial stromal polyp is the presence of stellate and multinucleate stromal cells which are identified near the epithelial-stromal interface. The mesenchymal cells of the polyp can also stain positive for actin, desmin, vimentin, estrogen and progesterone receptors.
Sarcomas are distinguished from the most malignant looking fibroepithelial polyps as sarcomas have identifiable tumor margins, cellular homogeneous distribution and absence of stellate and multinucleate stromal cells near the epithelial-stromal interface. Microscopic evaluation of the lesion in our case revealed polypoidal lesion lined by keratinised stratified squamous epithelium. Focally, it was ulcerated and replaced by fibrino-suppurative exudates. Sub-epithelial tissue showed dense collagenisation, mixed inflammation and ectatic blood vessels while deeper tissue was loose and showed scattered spindle and few stellate cells. Blood vessels of various calibre were also seen with few blood vessels thickened and dense lympho-plasmacytic infiltrate were seen along with perivascular inflammation suggestive of fibro-epithelial polyp of the vulva.
Absence of myxoid areas rules out possibility of aggressive vulval angiomyxomas.
As an adjunct to microscopic evaluation, imaging is also important in the diagnosis of fibroepithelial polyps. It evaluates blood supply and flow and determines the origin and extent of the tumor. Although CT and MRI may be used, they are not as cost effective or widely available as ultrasonography (USG). Therefore, USG is the first line imaging tool. USG also is fast, helps in real time determination of capacity for exploration and ability to visualize the entire lesion in a single image. The other differential diagnosis is botryoid embryonal rhabdomyosarcoma but these tumors are found in young pre-pubertal girls. There is absence of characteristic hypercellular subepithelial layer and there are specific immunohistochemical markers for skeletal muscle differentiation. These polyps can recur rarely, especially if they are not completely removed. Literature reports a case of growth of a giant cell fibroblastoma arising at the site of a previously excised stromal polyp. Due to this all patients with diagnosed fibroepithelial polyps should be followed up regularly. Fibro epithelial polyps though benign, most often resemble serious and malignant growths, as a result, histopathological evaluation is essential to rule out malignancy.
We thank Dr. Mona Agnihotri, Assistant Professor in Histopathology, Seth GS Medical College and K E M Hospital for her assistance in understanding the histopathology of the fibroepithelial stromal polyp. We thank Dr. Ashwini Desai (Third year obstetric and gynecology resident) for the intra-operative photos of our case.
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Srinivasan N, S Panchbudhe S. Fibro-Epithelial Polyp Of The Vulva. JPGO 2019. Volume 6 No.2. Available from: https://www.jpgo.org/2019/01/fibro-epithelial-polyp-of-vulva.html