Low Grade Endometrial Stromal Sarcoma: Unusual Gross Appearance

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Author Information

Ansari M*, Parulekar SV**.

(*Assistant Professor, ** Professor and Head, Department of Obstetrics and Gynecology, Seth GS Medical College & KEM Hospital, Mumbai, India.)

Abstract

Low grade endometrial stromal sarcoma is not a very common tumor of the uterus. Clinically it is mistaken for a leiomyoma of the uterus. Its gross appearance may be suggestive of its diagnosis. We present a case in which its gross appearance was quite unusual.

Introduction

Low grade endometrial stromal sarcoma is often mistaken for a leiomyoma of the uterus on clinical examination and on inspection of the external surface of the uterus during a laparotomy. The gross appearance of its cut surface may be suggestive of its diagnosis. But usually the specimen is not opened during the laparotomy and the diagnosis may be missed. The diagnosis is usually made after histopathological examination of the specimen. We present a case in which the gross appearance of the external surface of the uterus with a low grade endometrial stromal sarcoma was quite unusual.

Clinical Features

A 44 year old married woman, para 2 abortion 4, presented with menorrhagia for six months. Her past menstrual cycles were regular, and the flow was moderate. Her past, medical and surgical history were not contributory. General and systemic examination findings were normal, except for moderate anemia. Abdominal and bimanual pelvic examination showed the uterus was enlarged to 18 weeks’ size, globular, and with irregular upper surface. A diagnosis of uterine leiomyoma was made. Ultrasonography showed a well defined 10x8x8.5 cm sized mass with heterogenous echotexture in the uterine fundus with minimal vascularity, suggestive of a non-pedunculated leiomyoma. There was another 4.8x3.7x3.5cm sized lesion with similar appearance in the anterior wall of the uterus. Pap smear and endometrial aspiration cytology did not show any evidence suggestive of a malignancy. After correction of her anemia with transfusion of packed red cells and confirming that she was fit to undergo an operation, an exploratory laparotomy was performed. The findings are shown in figure 1. An abdominal hysterectomy and bilateral salpingo-oophorectomy was done. The patient made an uneventful recovery.

Figure 1. The uterus is enlarged. Three nodules with smooth external surface are seen over the uterine fundus anteriorly. A large vein is seen between two of these nodules.

Gross examination showed a uterus measuring 18x9x8 cm, with three small firm sessile masses measuring 3x2x2 cm on the anterior fundal wall. There was a large engorged vein running across anterior wall in between two of these masses. Cut surface showed involvement of the entire thickness of the myometrium by the tumor including the fundal nodules, but the serosa was intact. The mass extended into the endometrial cavity. Histopathology of the tumor showed tongues and sheets of neoplastic endometrial stromal cells in the full thickness of the myometrium. The serosa was intact. The tumor cells were oval shaped with basophilic mildly atypical nuclei and scanty cytoplasm. There was a prominent delicate arborizing vasculature throughout the tumor. Whorling of the neoplastic cells was seen around the arterioles. Two or three mitoses were seen per 10 HPF. There was no necrosis. A diagnosis of low grade endometrial stromal sarcoma was made.

Discussion

Low grade endometrial stromal sarcoma is not a very common tumor of the uterus. Clinically it is mistaken for a leiomyoma of the uterus. Its gross appearance may be suggestive of its diagnosis. It may be seen as a submucous polyp, or an intramyometrial mass. The classical gross appearance of an intramyometrial mass is either a single nodule, multiple solid-cystic masses, or a poorly demarcated solid-cystic lesion.^[1] About 50% cases are well circumscribed. Cut surface of the uterus shows worm-like masses penetrating the myometrium diffusely. Extrauterine extension is seen in 30% of cases. The diagnosis is usually made after histopathological examination.^[2,3] Most of the tumors involve the endometrium too.^[4]

Our case was unusual in that the tumor had grown as nodules on the uterine surface, but the serosa of these nodules was intact. A large vein between two of these nodules suggested vascularity, that might be due to underlying malignancy, though surface veins are known to occur with uterine subserous leiomyomas too.^[5] Such an appearance has not been described in the literature before.

Conclusion

In such cases of unusual presentation of leiomyoma, one should consider possibility of endometrial stromal sarcoma, even though endometrial aspiration cytology or histopathology of curetted material does not show any malignancy. 

References

1. Pekindil G, Tuncyurek O, Orguc S, Inceboz U, Kandiloglu AR, Caglar H. A case of endometrial stromal sarcoma with curvilinear calcification. Gynecologic Oncology 2005, 98:318-321.
2. Mesia AF, Demopoulos I. Effects of leuprolide acetate on low-grade endometrial stromal sarcoma. Am J Obstet Gynecol 2000;182:1140-1141.
3. Husseiny GE, Bareedy NA, Mourad WA, Mohamed G, Shoukri M, Subhi J. Prognostic factors and treatment modalities in uterine sarcoma. Am J Clin Oncol 2002, 25:256-260.
4. Berkowitz RS, Goldstein DP. Uterine cancer. In Berek JS, Hacker NE, editors. Practical Gynecologic Oncology. 4th ed. Philadelphia Williams & Wilkins; 2005:431-432.
5. Mirchandani A, Parulekar SV, Dalvi P. Hemoperitoneum from Ruptured Leiomyoma. JPGO 2014 Volume 1 Number 10. Available from: http://www.jpgo.org/2014/10/hemoperitoneum-from-ruptured-leiomyoma.html

Citation

Ansari M, Parulekar SV. Low Grade Endometrial Stromal Sarcoma: Unusual Gross Appearance. JPGO 2015. Volume 2 No. 4. Available from: http://www.jpgo.org/2015/04/low-grade-endometrial-stromal-sarcoma.html