Leiomyosarcoma of the rectum: a case report

Dr.Raad S. Alsaffar ,M.B.Ch.B, C.A.B.S., consultant surgeon and lecturer in general surgery, department of surgery and gasterointestinal center in Al-Sadur teaching hospital, Al-Najaf, Iraq.

Introduction

Rectal leiomyosarcomas are uncommon neoplasms, accounting for fewer than 1% of all malignancies of colon and rectum [1]. Besides its rarity, optimal treatment of rectal leiomyosarcoma is still not clear and the prognosis is poor. Herein we report case of rectal leiomyosarcomas with unusual presentation.

Case report

60 years old female patient presented at late October 2009, with fresh bleeding per rectum and deep rectal pain for 2 weeks duration. That was the 1st problem.

The patient sought medical advice, the provisional diagnosis was (bleeding haemorrhoids)? and medical treatment was given.

The 2nd problem was anaemia( Hb: 6 ), she had received 3 pints of blood, without specific workup.

The 3rd problem was severe relative constipation( >one week for each motion).

At mid December 2009, the patient underwent colonoscopy in GIT center of this hospital: the findings were large rectal pedinculated mass( 10×10 cm) near anal verge ,bleeding on touch with small diminutive polyps nearby the mass. Biopsy was taken.

The results of histopathology was : poorly differentiated adenocarcinoma.

CT-SCAN of the abdomen was done : large rectal mass (8×8 cm) filled lower rectal lumen and NO extra luminal extension, otherwise normal intraabdominal organs.

Then the patient arranged for abdominoperineal resection of the rectum.

The operation was done at 6th of January 2010, sequential AP excision of rectum, large rectal mass about 5 cm from anal verge, with intact serosa of rectal wall. End sigmoid colostomy was constructed.

Smooth postoperative course apart from simple wound infection and the patient discharged after one week hospital stay.

The results of histpathology : leiomyosarcoma of rectum.

Discussion

Leiomyosarcomas are rare tumors of the rectal wall. Colorectal leiomyosarcomas have a predilection for rectum and sigmoid colon and are commonly associated with rectal bleeding and pain [2]. Evans [3] reviewed 56 cases of smooth muscle neoplasm of gastrointestinal tract followed for a minimum of 10 years; only 4 of them was located in the rectum. Randleman et al [4] reported a series of 22 cases of rectoanal leiomyosarcoma seen over 35 years and Walsh et al [5] reported a series of 48 anorectal leiomyosarcoma in 31 years.

Symptoms seen frequently included changes in bowel habit, rectal pain, pressure, and bleeding. One of our patient was admitted with the complaints of rectal pain and the other with rectal bleeding. Rectum leiomyosarcoma can originate from muscularis mucosa, muscularis propria, or the wall of blood vessels. They may grow into the lumen or into the perirectal tissues [6,7]. The mucosa is involved in about 30-50% of the cases [6]. Since mucosa is uninvolved in our first patient, a gynecological pathology was initially considered until rectal symptoms became apparent. Lymphatic metastases are rare. Blood-borne metastases to the liver and lungs are the most common cause of death [6].

Optimal treatment of rectum leiomyosarcoma is unclear. Since high grade and/or large leiomyosarcoma (>5 cm) tend to have a worse prognosis, conservative surgical approaches such as wide local excision appear to be insufficient. In small (£3 cm), and localised (£T2) tumors with low grade histological appearance, conservative surgery may be sufficient [8]. By the year 1994, Khalifa et al [9] reviewed 135 cases of rectum leiomyosarcoma from the literature and reported a recurrence rate of 67.5% after local excision and suggested that the abdominoperineal resection should be the procedure of choice for rectal leiomyosarcomas. Besides that, some authors claim wide local excision would be enough for lesions <2.5 cm which are localised to the intestinal wall [1]. Transrectal ultrasonography would be helpful when conservative surgery is planned to define the extent of disease [1,8]. In our first patient, conservative surgery in the form of wide local excision did not prevent local recurrence. Furthermore, adjuvant radiotherapy and chemotherapy following abdominoperineal resection, did not prevent local pelvic recurrence in this patient. Although some authors claim that postoperative radiotherapy is beneficial [10], others suggest adjuvant chemotherapy and radiotherapy should be given only in the context of a clinical trial [7,8,11].

There is no definitive treatment strategy for rectal leiomyosarcomas, but surgery is the main treatment modality. As other sarcomas, leiomyosarcomas are chemoresistant and radioresistant so the efficacy of adjuvant treatment is unclear. The prognosis of rectal leiomyosarcoma is poor and the survival rates after radical surgical treatment ranges between six months to six years6]. Since five year survival rate is only 20%, more effective adjuvant chemotherapeutic regimens should be evaluated postoperatively .7].

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