Aggressive Angiomyxoma of Vagina

Aggressive (Deep) Angiomyxoma of Vagina: A rare case report

Department Of Anaesthesia Cancer Hospital, Aurangabad

Submitted By: Dr Narendra Patil, Dr Manjushri Waikar, Dr Vijay Kalyankar, Dr Shrikrishna Chavan, Dr Jyoti Kodgire, Dr Sonal Bhalerao

Abstract:

Aggressive Angiomyxoma (AAM) is rare, localy aggressive mesenchymal tumour that has a high propensity for local reccurance {exceeding 35%}. It is extremely rare to metastasize & involves mainly Pelvis, Perineum, vulva, Vagina & urinary bladder in women of reproductive age group with peak incidence in 3rd & 4th decade. However few cases of its occurrence outside the pelvis have also been reported.

Aggressive angiomyxoma (AAM) was identified as a distinct clinicopathic entity in 1983 & since then fewer than 250 cases of this rare tumour have been reported in world of literature. Angiomyxoma is called as aggressive due to neoplastic nature of blood vessels, localy infiltrative behavior & high risk for local recurrence, however metastasis are extremely rare.

Diagnosis is mainly made on histopathology after surgical resection and because of its rarity it is often initially misdiagnosed. Surgical resection is the main treatment modality of angiomyxoma.

We report a case of aggressive angiomyxoma in 45 years old pre-menopausal female presented with a vaginal mass on anterior vaginal wall in which diagnosis was only made after histological examination.

Key words: aggressive angiomyxoma, pelvic, vulvo- vaginal neoplasm, reproductive age, rare to metastasize.

Introduction:

Case of aggressive angiomyxoma (AAM) was first described as a distinct clinic pathologic entity by Steeper & Rosai in 1983. AAM is a rare tumour of mesenchymal origin. About 90% of the patients are women in reproductive age group with peak incidence between 3rd and 4th decades of life.

AAM usually arises in deep soft tissue of vulvovaginal region, perineum, pelvis of young adult females and analogous sites including scrotum and inguinal area in males. It is slow growing tumour but problematic due to frequent local recurrence(30-72%). Female to male ratio is 6.6/1 .

However metastasis are very un-common. Misdiagnosis is very frequent problem. Diagnosis is mostly made on histopathology following surgical resection. We report a case of aggressive angiomyxoma in pre-menopausal 45 years female presenting with vulvo-vaginal mass on anterior vaginal wall.

Case Report:

A 45 years old premenopausal female patient, para2Live2, visited to gynecology outpatient department with Complaints of painless mass in the vagina gradually increasing in size over last 8 years, now protruding out of the vagina and dyspareunia since last one year. Patient had no relief of the symptoms on seeking medical advice from the local practitioner.
No bladder or bowel complaints.

Menstrual histroy - past menstrual cycles were regular. Last Menstrual Period was 7 days before.
Obstetrical history - Para2Live2, all full term normal delivery, last child birth 14 years before.
General and Systemic Examination - Patient was averagely built, afebrile, pulse was regular, mild pallor, no icterus. Cardiovascular and Respiratory system revealed no abnormality, per Abdomen soft with no guardening and rigidity. No systemic signs of thyroid disorder found on examination. Local Clinical examination revealed a well defined firm irregular mass of 7*6*5 cms, which was non tender, arising from anterior vaginal wall in suburethral region, 4 cm below the urethral meatus with wide base as seen in photograph. Posterior vaginal wall and cervix were healthy as seen in photograph. Uterus was anteverted and normal size, fornices free and non tender, per rectal examination revealed no mucosal involvement.
Investogram - Her investigations revealed hemoglobin - 11.8 g/dl, total white blood cell count(TLC) 12680/ cumm, platelet -4.2 lakhs/cumm, Sr Bilirubin 0.6 mg/dl, Blood sugar random 104 mg/dl, SGOT 26 IU/L, SGPT 25 IU /L, Blood urea 29 mg /dl, Sr creatinine 1 mg/dl. HIV and Hepatitis B surface antigen were non reactive.
X ray chest was within normal.
Histopathlogy report of the pre-operative biopsy (done twice) showed inflammatory changes with no tissue diagnosis.
CECT was performed for better characterization and the extension of tumour. It revealed an ill defined heterogeneously enhancing soft tissue mass lesion of size 10.5*5.3*7.8 cm, arising from anterior vaginal wall, extending inferiorly in subcutaneous plane in vulval region. Superiorly extending up to anterior lip of cervix. Fat planes between this mass and bladder were well maintained. Hence surgery was planned after evaluation for possibility bladder involvement by the surgeons. aggresive 1aggressive 2 Procedure performed - Removal of the vaginal mass was done in lithotomy position. Under spinal anesthesia per speculum & per vaginal examination were done to confirm pre-operative findings. Patient was catheterized to facilitate the surgery and to prevent trauma to urethra.
Mass was identified 4 cm below from urethral meatus. To develop the tissue planes normal saline was infiltrated around the mass, and circumferential incision was taken at the base of mass (bladder approximately 2.5 cms away from the mass). The base of the pedicle was separated with sharp dissection, and the base of mass was dissected from the vaginal wall in the region of the pedicle. The dissection was easy. The base of the pedicle was reached posterior to symphysis pubis. The base of the pedicle was clamped as close to the hind surface of the symphysis pubis and the polyp growth was removed. At the end of the procedure there was no visible or residual palpable mass. Haemostasis was achieved and the incision was closed with 2-0 vicryl. Vagina was packed and the pack was removed after 24 hours catheter was removes after 7 days.
On gross examination mass was well circumscribed measuring 8*8*7*cm in size (as seen in photograph) and weighing 65 gm. On cut section it appeared gelatinous, glistening and bluish-grey in color.
aggressive 3aggressive 4aggressive 5aggressive 6
On Histopathology - Haematoxylin and eosin stain revealed tumor tissue composed of small and large vessels lined by endothelium surrounded by smooth muscle coat with myxomatous stroma. Tumor covered with thin layer of epidermis with fairly uniform, moderate cellularity containing small, stellate–shaped and spindled cells, in myxomatous stroma. Suggesting angiomyxoma. Immunohistochemistroy not done in this case as patient was poor and at Government Medical College and Hospital, Aurangabad this test is not available.
Post operative patient was observed in the hospital for bleeding and urinary leaks for 7 days and was treated with prophylactic antibiotics. The follow up was uneventful with no signs of recurrence. Histopatology - Histopathology revealed thin uniform epidermis, small & large vessels lined by endothelium surrounded by smooth muscle coat. Stroma is myxomatous spindle and stellate cells seen.

Discussion:

The term aggressive angiomyxoma was coined by Steeper and Rosaii in 1983 for a morphologicaly distincitive, slow growing, myxoid neoplasm that occurs mainly in genital, perineal, and pelvic region of adult women. It is of two types;

  1. Superficial - which grows near surface
  2. aggressive - which grows & invades in deeper tissues & has tendency for recurrence 90% patientapos;s are in reproductive age group

Patient usually presents with noticeable mass and rarely have pain. The initial presentation varies from asymptomatic perineal or vulval nodule or polyp or perineal hernia to a pelvic mass diagnosed on imaging study. In this case premenopusal patient presented with painless mass increasd in size over last 8 years.
Occasionally tumour can be cystic and mistaken for Bartholins, labial, or Gartner duct cyst. The tumour characteristically grows slowly and insidiously. It usually takes 2 months to 17 years for patient to report to the hospital.
Genetics - The pathogenesis of the aggressive angiomyxoma is poorly understood; however genetic alterations along the 12 q chromosome region Chromosomal abnormality involving chromosome 12q 13-15 have been implicated. These translocations involve High Mobility Group A protein (HMGA2). HMGA2 belongs to a family of transcription factor that function during embryogenesis and usually not detected in adult tissues. Cytogenetic analysis & fluorescent in situ hybridization have confirmed the presence of HMGA2 gene in the rearrangement in aggressive angiomyxoma.
Immunohistochemically - Most aggressive angiomyxoma express different combination of estrogen and progesterone receptors and shows immunopositivity for vimentin, desmin, smooth muscle actin, muscle specific actin, CD 34 and CD 44. They showed strong immunoreactivity for actin but were negative for S-100 protein.
In this case Immunohistochemistry was not done as patient was poor and test is not available in Government Medical Hospital, Aurangabad.
Gross Appearance - Tumour size ranges from 3 to 60 cm. It can appear as Polypoid, Soft, bulky mass or vaginal cyst. External surface is smooth and usually neither encapsulated nor circumscribed. It has gelatinous consistency with focal areas of congestion & haemorrhage on cut section. It is usually homogenous in consistency with no obvious nodularity.
In this case on gross examination mass was well circumscribed measuring 8*8*7*cm in size. On cut section it appeared gelatinous, glistening and bluish-grey in color.
Microscopic Appearance - Spindle stellate cells separated with loose myxoid stroma focally rich in collagen fibrils, a prominent vascular component. Mitotic activity is extremely low.
In this case histopathology revealed tumor tissue composed of small and large vessels lined by endothelium surrounded by smooth muscle coat with myxomatous stroma. Tumor covered with thin layer of epidermis with fairly uniform, moderate cellularity containing small, stellate–shaped and spindled cells, in myxomatous stroma. Suggesting angiomyxoma.
Scanning - Several imaging modality have been used in identifying and describing aggressive angiomyxoma. Sonography usually reveals hypoechoic or cystic mass. CT & MRI are useful in diagnosis and help in complete removal of tumour particularly arising in perineum, vulva and bladder. Aggressive angiomyxoma display unuasual growth pattern with high signal density in T2 weighted MRI. MRI scan shows a “swirled” pattern visible in the angiomyxoma and is more specific than CT scan, so imaging study of choice for these lesions. In this case CECT revealed an ill defined heterogeneously enhancing soft tissue mass lesion of size 10.5*5.3*7.8 cm, arising from anterior vaginal wall, extending inferiorly in subcutaneous plane in vulval region extending superiorly up to anterior lip of cervix. Fat planes between this mass and urinary bladder were well maintained. Differential Diagnosis of AAM -

Treatment & Prognosis:

First line of therapy for aggressive angiomyxoma is surgery although achieving negative resection margins is difficult because of the infiltrative nature of tumor and the absence of defined capsule.
Smaller and more superficial tumor of the vulva or vagina may be removed with wide local excision, but larger, deep seated tumors of pelvis may require more extensive surgery with partial or complete resection of some pelvic organ. The recurrence rate is very high (more than 35%).
Most of the aggressive angiomyxoma tumour shows estrogen and progesterone receptors and are likely to be hormone dependant. Hormones can be given pre-operatively to decrease the tumour size.
Preoperative GnRH analogues have been used successfully in few instance in premenopausal women with aggressive angiomyxoma having positive estrogen and progesterone receptors. Pre-operative use of GnRH analogue decreases the tumour size and makes the complete removal of the tumour feasible.
Due to low mitotic activity in these tumours radiotherapy and chemotherapy are of not much help. Angiographic embolisation has been attempted to shrink the tumour. Two cases of successful control of recurrent angiomyxoma with relatively high doses of external radiotherapy have also been reported.

Two cases of metastasis had been reported in literature;

  1. Pulmonary and mediastinal metastasis
  2. Metastasis to lung

Recurrence is one of unique characteristics of these otherwise non–malignant tumors. The usual sites of recurrence reflects the site of the primary disease i.e. perineum, pelvis. No definite relation between patientapos;s age, size of tumor and rate of recurrence has been established so far.
Many options for the treatment of recurrence, such as repeat surgery radiotherapy and hormonal therapy have been tried with varying success, but no single modality is clearly beneficial over others. All patients need long term follow up, usually with clinical examination and MRI to detect early recurrence.
In our case we resected the tumor with no visible or palpable residual tumor and there are no signs of recurrence after 3 months.

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