Niphadkar M*, Parulekar SV**
(* Third Year Resident, ** Professor and Head, Department of Obstetrics and Gynecology, Seth G S Medical College & KEM Hospital, Mumbai, India.)
Inflammatory myofibroblastic tumor is of unknown etiology. It present at various sites, in relation to important structures. There are only six cases related to female genital tract reported in literature. We present a case in which the tumor was projecting into the vagina. This is the first case of this type in the world literature.
Though called inflammatory, IMT is a neoplasm. It is multifocal and has a 35% chance of recurrence and metastases.[1,2] Its most common site is the lungs. It can also occur in the urinary bladder, kidney and ureter.[3,4,5] We present case in which the tumor was closely related to the urinary bladder, uterus and vagina and presented as a vaginal mass. It is the first case of its type in the world literature.
A 34 year old female, para 2 living 2, previous full term normal deliveries, came to the gynecology clinic with the complaints of a painless vaginal swelling and dragging sensation in the pelvis. She also brought a MRI report which read as follows:
‘A well encapsulated T2 hyperintense lesion with multiple fibrotic strands within seen in the lower abdomen from L3 upwards and extending into the pelvis up to the right ischiorectal fossa. It is causing displacement of the uterus, cervix and the upper two thirds of the vagina to the left and insinuating into the right lateral fornix. No intrauterine/ intravaginal component noted. Presacral extension of the lesion is seen which is heterogenous. Similar heterogeneity is seen in the lower pelvic anterior component. Both ovaries are seen separately from the lesion. MRI findings are of a fairly large fat containing pelvic lesion with significant inferior extension. Liposarcoma is to be considered.’
Figure 1. MRI Appearance of the tumor.
On clinical examination, a mass protruding from the right lateral vaginal wall was seen. Its surface was smooth and covered with normal vaginal epithelium. On per vaginum examination, the mass was firm, painless and compressible. It was found to be extending upwards under the right obturator fossa and behind the right pubic ramus closely related to it. It was closely related to the right side of the uterus, which was displaced to the left. Rectal examination showed the rectal mucosa to be free, and the mass to be on its right side. No obvious swelling over the back seen.
Figure 2. Speculum examination showing the mass projecting into the vagina from the right side.
Her Pap smear was normal. An ultrasonographic scan was obtained, which showed 10.3x7.2 cm sized soft tissue mass near the right adnexa going towards the right paravesical region up to the anterior abdominal wall, displacing the bladder to the left. It was isoechoic to fat.
The patient was referred to gastrointestinal surgery department for the further management of the retroperitoneal tumor. A computed tomography (CT) showed a 20x14x13 cm mass extending up to right ischiorectal fossa, presacral region and anterior abdominal wall. Fat planes were maintained around the mass. Multile mesenteric lymph nodes measuring less than 1 cm in diameter were seen. A CT guided biopsy was obtained. However the sample was inadequate and no diagnosis could be made, though angiomyoliposarcoma was suspected. So she was referred to an oncology center for neoadjuvant radiotherapy and chemotherapy and was to be scheduled for surgery later. She underwent an exploratory laparotomy and excision of the mass without any prior radio- or chemotherapy. The mass could be excised completely, including the part projecting into the vagina. The urinary bladder was opened accidentally during the surgery. It was repaired after placing a DJ stent in the right ureter. The patient made and uneventful recovery. She was prescribed tamoxifen 20 mg q12h for 9 months. The DJ stent was removed after 1.5 months. She was well 3 months after that.
Histopathological examination of the mass showed a nonencapsulated spindle cell tumor with fibrosis in the background and fat entrapment. Nuclear pleomorphism and atypical mitoses were absent. Immunohistochemistry showed the tumor cells to be diffusely positive for SMA, focally for Desmin, and negative for beta catenin. A diagnosis of inflammatory myofibroblastic tumor was made.
The unusual presentation in this case could be easily confused with a vulval lipoma. Like majority of the patients with retroperitoneal tumours, our patient never had any urinary symptoms or any other pressure symptoms. The interesting part was the extension of the tumour from the retroperitoneal compartment to the anterior pelvic compartment thus presenting as a swelling in the vagina.
Retroperitoneal tumors always present as large asymptomatic masses, nearly 50% are >20 cm at the time of diagnosis. Very rarely will they present pain, swelling and edema due to impingement on the bone or neurovascular bundle. Our patient had a large mass, which was associated with a little dragging pain. IMT is usually arising from an important organ which can be damaged during removal of the tumor. In our case the urinary bladder was injured. But despite its location in the retroperitoneum passing close to the uterus and ureter in the right broad ligament and close to the bladder, the ureter was not involved and was not injured during the surgery. The vaginal extension of the mass could be removed entirely by the abdominal approach. Based on the MRI and USG report, the tumor in this case was initially thought to be a lipoma, which could have been a lipoma, angiolipoma, fibrolipoma, myelolipoma or spindle cell lipoma. It could also have been a liposarcoma. IMT is a not common condition and is not thought of in the differential diagnosis of retroperitoneal masses. In the case presented it turned out to be IMT. A preoperative diagnosis is important in management of the tumor. The features are quite distinctive.[6,7,8]
The diagnosis could have been made preoperatively by obtaining a biopsy of the vaginal mass quite easily. However the surgeons were reluctant to do so, fearing a breach in the surface of the mass and metastases.
Surgery remains the mainstay for the treatment of IMT. Medical treatment may be useful as adjuvant therapy. Prolonged follow up is essential to detect a recurrence or metastases early.
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Niphadkar M, Parulekar SV. Retroperitoneal Inflammatory Myofibroblastic Tumour Presenting As A Vaginal Swelling. JPGO 2016. Volume 3 No. 10. Available from: http://www.jpgo.org/2016/10/retroperitoneal-inflammatory.html