Introduction

Leiomyosarcoma is the malignant counterpart of leiomyoma. Leiomyosarcoma occurs mainly after menopause, an older average age group than leiomyomas (median age, 54 years) although they can also occur in younger patients.^[1] It is the most common sarcoma of the uterus, with incidence of 2 to 3 for every 1,000 women with leiomyomata. African Americans have higher occurrence rate.^[2]

Some epidemiologic findings in patients with leiomyosarcoma parallel those from studies in endometrial carcinoma and suggest a role for unopposed estrogen stimulation.^[3] The genetics of leiomyosarcomas have confirmed that they do not arise from leiomyoma.

The relative rarity and pathological diversity makes it difficult to define the optimum management. We report a case of 60 year old female who presented with post- menopausal bleeding with endometrial polyp and was diagnosed later to be a case of leiomyosarcoma of uterus.

Case Report

A 60 years old female of north Indian origin, reported to outpatient clinic, Khandwa on 5^th October 2022 with the complaint of postmenopausal bleeding since 4 months and lower abdomen pain for 3 months. Bleeding was off and on and irregular in nature.

Abdominal pain was mild in intensity, non-radiating and having no variability with change in posture or respiration. There was also a history of weight loss and decreased appetite over 2 months. There were no associated bowel or bladder complaints. There was no history of long term illness or any chronic disease or any prior hospitalization.

On examination

Patient was moderately built. Vitals were stable with blood pressure was 138/90 mm Hg, pulse rate 74/min and respiratory rate 18/min, no pallor present.

On per abdominal examination, an irregular midline mass arising from the pelvis was present. The upper and lateral borders of the mass could be made out, lower margin could not be ascertained. The mass was firm to hard in consistency with restricted mobility and non tender with no free fluid. There was no hepatosplenomegaly.

On vaginal examination, the cervix was directed backwards, uterus was anteverted, around 20 weeks size and mobile, B/L fornices were clear, no tenderness was observed.

The IHC profile of this case

Endometrial stromal nodules and sarcomas are diffusely positive for CD-10 and negative for desmin. Whereas cellular leiomyomas and leiomyosarcomas are usually positive for CD10 and positive for desmin, immunohistochemistry can be helpful in difficult cases. ^[4], ^[5]

Carcinosarcoma was also a differential diagnosis as they commonly present as a uterine polyp in post menopausal women. But in our case, there was absence features of endometrioid, serous or clear cell type adenocarcinoma. ^[6], ^[7] Ultrastructurally and immunohistochemically, the features of leiomyosarcoma are those of smooth muscle cells. ^[4]

Leiomyosarcoma show consistent immunoreactivity for smooth and common muscle actin, desmin, calponin , h-caldesmon and vimentin. Endometrial stromal sarcoma show sensitivity for CD-10, ER, PR and cyclin D1. ^[8]

In our case, Tumor cells were positive for vimentin, desmin, h caldesmon, p-53 and focally SMA. Also, Tumor cells were negative for PanCK, S100, CD34, ER, CD10, Cyclin D-1, CD117.

In contrast to leiomyoma, there is commonly TP53 mutation in leiomyosarcoma, which results in overexpression of p-53 as in our case.

Ki- 67: 50%

Conclusive diagnosis by IHC was Leiomyosarcoma.

Immunoh- istochemistry	h- Caldesmon	CD-10	Desmin	Cyclin D1
Leiomyos-	Positive	Negative	Positive	Negative
Endometrial stromal sarcoma	Negative	Diffusely positive	Negative	Positive

Table 1

Discussion

Uterine sarcomas are rare and constitute about 2% to 5% of all malignancies with annual incidence of 0.64 per 1,00,000 women. Although leiomyosarcomas can occur else where in the pelvis, including the cervix and urinary bladder, it is more commonly found in uterus. Signs and symptoms resemble those of the far more common leiomyoma and preoperative distinction between the two tumors may be difficult. Our patient presented with complaints of postmenopausal bleeding since four months.

At molecular level, there is no evidence of progression from leiomyoma to leiomyosarcoma and approximately 0.5% of women who have hysterectomies for uterine fibroids are found to have leiomyosarcomas. ^[9], ^[2]

SMA, MSA and vimentin were shown by many researchers to have little reliability in differentiating endometrial stromal neoplasms from uterine smooth muscle tumors. However there appeared to conflicting results regarding the discriminatory value of desmin for this differential diagnosis. Olive et al. ^[10] demonstrated that highly cellular uterine leiomyomas were positive for desmin, whereas endometrial stromal nodules and ESSs were negative.

Uterine leiomyosarcomas are aggressive tumors with high rates of recurrence. ^[11], ^[12] The uterine sarcoma is made from histologic examination of entire uterus as seen in our case.

Leiomyosarcoma has a poor prognosis. Prognostic factors include tumor size >5 cm and high mitotic index. The most common mode of spread is hematogenous.

Surgical intervention is the treatment of choice with Total abdominal hysterectomy, bilateral salpingo – oophorectomy for postmenopausal females and those with metastatic disease and Total abdominal hysterectomy without bilateral salphingo – oophorectomy for premenopausal females.^[5] Hormonal therapy may be an option in hormone receptor positive tumors.

Conclusion

It is important to differentiate endometrial stromal sarcoma from uterine leiomyosarcoma, which is vital due to their clinical course and management. IHC panels along with gross and microscopic examination play a major role in reaching a definitive diagnosis.

Conflict of Interest

None.

Source of Funding

None.