Introduction

Aggressive angiomyxoma is a rare locally invasive soft tissue tumour arising from the perineum. First reported by Steeper and Rosai in 1983, it is usually asymptomatic and presents as a mass in the perineum [1]. Aggressive angiomyxoma is thought to be estrogen progesterone sensitive and occurs usually in the reproductive age group [2]. Here, we present a case with an uncommon origin of this rare tumour.

Case Presentation

A 23-year-old woman presented to the outpatient clinic with complaints of excessive vaginal bleeding for three days after an abortion. It was her first pregnancy and she aborted spontaneously at home. She had a four month period of amenorrhea but a pregnancy test or ultrasound had not been done. Previous menstrual cycles were normal and regular. General examination was unremarkable except for evidence of anemia. Pelvic examination revealed a large fleshy polypoidal mass protruding from the cervix which was felt high up in the vagina. Though the patient did have some dyspareunia and vaginal discharge, there was no history of post coital bleeding.

Urine pregnancy test was negative. Ultrasound showed a large 8 cm x 6 cm x 5 cm fibroid polyp in the cervix. The differential diagnoses of a cervical polyp or a retained placental polyp after spontaneous abortion were considered. The lady underwent removal of the cervical polyp under spinal anaesthesia. The cervix was ballooned and dilated. The large fleshy polyp was divided into 2 parts for removal. The blood loss was approximately 20 ml. The specimen was sent for histopathology (Figure 1).

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   Figure 1:

   
   Gross specimen showing bisected polyp with homogeneously smooth and glistening sectioned surface.

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   Figure 1

   

   Gross specimen showing bisected polyp with homogeneously smooth and glistening sectioned surface.

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The patient was discharged in a satisfactory condition on post-operative day three. The histopathology of the cervical polyp (Figure 2) unexpectedly reported low cellularity with scattered spindle cells in a myxoid background; features suggestive of aggressive angiomyxoma (AAM) of the cervix (Figure 3). The immunohistochemistry was positive for smooth muscle actin (SMA), vimentin and desmin while S-100 was negative (Figure 4). The excisional margins were free of tumor and the surgical treatment was complete. However, aggressive angiomyxoma has a high rate of local recurrence and long term follow up is required which in our case would include clinical symptomatology, physical examination and imaging with either ultrasound and/ or magnetic resonance imaging (MRI) of the pelvis to evaluate the uterus and adnexa. In case of recurrence, a hysterectomy may be required to completely remove the local uterine disease. All the same, our patient is since lost to follow up and has not reported back in the last 2 years.

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   Figure 2:

   Photomicrograph showing endocervical mucosa lined tissue with presence of tumour composed of vascular channels in the subepithelial tissue (H&E, x200).

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   Figure 2

   

   Photomicrograph showing endocervical mucosa lined tissue with presence of tumour composed of vascular channels in the subepithelial tissue (H&E, x200).

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   Figure 3:

   Bland scattered spindle shaped cells in a loosely textured myxoid stroma with capillary sized (arrows) to thick walled blood vessels (block arrow) (H&E, x200).

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   Figure 3

   

   Bland scattered spindle shaped cells in a loosely textured myxoid stroma with capillary sized (arrows) to thick walled blood vessels (block arrow) (H&E, x200).

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   Figure 4:

   Photomicrograph showing immunopositivity for desmin on the left (IHC, x200) and neoplastic spindle shaped cells with intense cytoplasmic positivity for vimentin on the right (IHC, x600).

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   Figure 4

   

   Photomicrograph showing immunopositivity for desmin on the left (IHC, x200) and neoplastic spindle shaped cells with intense cytoplasmic positivity for vimentin on the right (IHC, x600).

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Discussion

Aggressive angiomyxoma is a rare mesenchymal tumour that presents to the gynecologists as a growth/ mass arising from the vulva or perineum; mistaken as a lipoma, bartholin, gartner's cyst or labial mass and has no typical symptoms [2-4]. Patients are often asymptomatic and compression to urinary/intestinal systems occurs only when the tumour is large. Very rarely, and to our knowledge, only two cases have been reported where it has presented as a cervical polyp with symptoms of distension or a uterine polyp where it presented with uterine bleeding and urinary retention [5,6]. Aggressive angiomyxoma is thought to be estrogen and progesterone sensitive and presents usually in the reproductive age group, with some cases reporting growth of the tumour during pregnancy [2,7]. The elevated hormone levels during the antecedent pregnancy may have contributed to growth of the tumour in our patient too. However, the peculiar location of the tumour in our patient probably led to the dilation of the cervix that led to the spontaneous abortion in this patient.

An accurate diagnosis of aggressive angiomyxoma is based on histopathology evidence. Grossly these tumours have a smooth surface with homogenous consistency and a glistening gelatinous appearance on cut section [1]. Microscopy shows a hypocellular mesenchymal lesion with scattered bland spindled and stellate cells in a myxoid stroma. The tumour lacks cytologic atypia, increased/atypical mitoses and coagulative necrosis. Characteristic are the numerous blood vessels of varying calibre as seen in the current case. The tumour is usually positive for vimentin, desmin and negative for S-100 on imomunohistochemistry [8]. However, this immunoprofile is shared by superficial cervicovaginal myofibroblastoma [9]. Sparse cellularity, more infiltrative pattern and variability in distribution, size and wall thickness of vessels favour aggressive angiomyxoma.

Aggressive angiomyxoma is rare and usually presents with a slow growing mass due to which it may be mistaken for a benign growth. Pathologically, aggressive angiomyxoma needs to be differentiated from angiomyofibroblastoma (AMF), myxoid leiomyoma, cellular angiofibroma, superficial myofibroblastoma, myxoid liposarcoma and other differentials that may mimic aggressive angiomyxoma and differ in the management, thus emphasizing the need for pre-operative diagnosis [7,10]. Prior to definitive management, a pre-operative fine needle aspiration (FNA) may help exclude lymphoproliferative and metastatic pathologies [10]. Radiological assessment of extent of lesion using radiological modalities like ultrasound, computerized tomography (CT) and MRI should be considered to help plan surgery [7,11]. On CT, it is seen as a well-defined mass, hypodense as compared to the muscle. AAM is seen as a hypointense lesion on T1 weighted MRI images and hyperintense lesion on T2 weighted images [11].

Angiomyxoma is thought to displace rather than invade surrounding tissue. In the usual case of AAM presenting as a perineal mass, careful anatomic dissection should be done to avoid injury to anal sphincters and lower urinary system that may be in close proximity in an AAM [2,4]. In case of a cervical or uterine polyp, the complete removal of the polyp and the pedicle should be done to ensure disease free margins, which should be confirmed by histopathology, as in our case. AAM has high recurrence (36-72%), is locally invasive and few metastasis have been reported [2,3,11,12]. Surgery with wide excision and tumour free margins has been advocated [2-4]. However, the chances of local recurrence are similar with complete tumour free margins and without [2,11]. Follow up assessment of treatment response should include clinical examination and CT/ MRI [2]. Our patient was planned for follow up with CT/ MRI to assess for recurrence, especially in the cervix, uterus and pelvis. In case of involvement of the cervix/ uterus, local resection would warrant a hysterectomy.

Other therapeutic options could be used to preserve fertility. These include hormonal treatment with gonadotropin releasing hormone (GnRH) agonists or tamoxifen [3,11,13]. Leuprolide acetate administered intramuscularly in monthly doses of 3.75 mg has been used [14]. Tamoxifen has also been used in the treatment of aggressive angiomyxoma due to its antiestrogenic action [12]. These agents may help in reducing the extent of surgery by reducing the size of the tumour [11]. Even though radiotherapy and chemotherapy may seem to be less useful due to the low mitotic activity and low cellularity of the tumour, various reports have documented reduced recurrence with their use [7,15]. The presence of multiple feeding vessels also limits the use of embolization as a treatment modality [11]. Individualization of the treatment options and multimodal treatment seem to be the most appropriate [16,17].

Conclusions

Aggressive angiomyxoma should be considered in the differential diagnosis of a uterine or cervical polyp, especially when presenting in pregnancy. When presenting as a polyp, aggressive angiomyxoma could lead to spontaneous abortion. Treatment options include surgical resection and hormonal therapy like GnRH agonists and tamoxifen. In case of uterine/ cervical polyp, reappearance of symptomatology, ultrasound, CT/ MRI and curettage may be used to assess for recurrence. In case of recurrence of angiomyxoma, local resection may require hysterectomy. Conservative options in the form of GnRH agonists and tamoxifen may be offered to preserve fertility. Long term follow up is recommended.