Leiomyosarcoma of the rectum and anus. A series of 22 cases

Anal leiomyosarcoma: A case report and review of literature

INTRODUCTION

Leiomyosarcoma is a malignant neoplasm that is derived from smooth muscle cells in walls of small blood vessels or branch of the inferior vena cava, the uterus and the gastrointestinal tract. Different treatment options are present for the treatment of LMS. However, due to the rarity of LMS, the optimal treatment option is still to be discussed and determined.

PRESENTATION OF CASE

A 51-year-old male patient, previously healthy, presented for perianal pain. Biopsy of the mass found showed spindle cell tumors with mild atypia, dense cellularity, and pelvic MRI with contrast showed a well-circumscribed mass of the anus, developed between the layers of the external sphincter with possible invasion of the internal sphincter consistent with Leiomyosarcoma Grade I. Wide excision was performed. Close follow-up should be done every 3 to 6 months for the first 2 to 3 years, every 6 to 12 months for the following 3 years, and annually afterwards.

DISCUSSION

The symptoms of LMS include rectal bleeding with rectal and/or abdominal pain, weight loss, constipation, altered bowel motion and protruding mass. Treatment options include wide local excision, abdominoperineal resection, low anterior resection, bloc resection and pelvic exenteration. Patients who underwent wide local excision show a higher local recurrence rate as compared to patients who underwent radical resection. Distant metastasis is higher in patients who underwent radical resection.

CONCLUSION

The treatment options of anal LMS are controversial. At present, very few cases have been reported, thus no universally accepted standard of surgical treatment has been established.

Leiomyosarcoma of the lower rectum managed by radiotherapy and surgery: A case report and review of literature

Rectal leiomyosarcoma is a very rare entity. Surgery is the main treatment, but the place of radiation therapy remains unclear. A 67-year-old woman was referred for a few-weeks' history of bleeding and anal pain intensified during defecation. Pelvic magnetic resonance imaging (MRI) showed a rectal lesion and biopsies revealed a leiomyosarcoma of the lower rectum. She was free of metastasis on computed tomography imaging. The patient refused radical surgery. After discussion by a multidisciplinary team, the patient received pre-operative long-course radiotherapy followed by surgery. The tumor was treated with 50Gy delivered in 25 fractions, within 5 weeks. The aim of radiotherapy was local control, allowing organ-preservation. Four weeks after radiation therapy, organ-preservation surgery could be performed. She had no adjuvant treatment. At 38-months follow-up, she had no local recurrence. However, distant recurrence (lung, liver, and bone) was detected 38 months after the resection and was managed by intra-venous doxorubicin 60mg/m² and dacarbazine 800mg/m² every 3 weeks. The patient was in a stable condition for nearly 8 months. The patient died 4 years and 3 months after the diagnosis.

The importance of surgical resection in the management of rectal sarcoma: A national cancer database analysis of 133 cases

BACKGROUND AND PURPOSE

Rectal sarcomas (RS) are rare malignant tumors with a very poor prognosis. This study aimed to assess the characteristics, treatment, and outcomes of RS in the United States.

METHODS

This study was a retrospective analysis of the National Cancer Database (NCDB) from 2004 to 2019 of patients with a diagnosis of RS. The main outcome measures were overall survival (OS) and its predictors.

RESULTS

133 RS patients (39.1% female) with a mean age of 65.7 ± 15.6 years were included in the study. Mean tumor size was 6.1 ± 3 cm. The crude OS rate was 22.5% and median survival duration was 10.1 (IQR: 3.2-21) months. Factors associated with an improved OS on were private insurance (HR = 0.23, p = 0.001) and undergoing surgery (HR 0.23, p < 0.001), Factors associated with poor survival were age (HR 1.02, p = 0.005), male sex (HR 2.27, p = 0.001), Charlson score of 3 (HR 5.17, p = 0.003), and positive resection margins (HR: 2.64, p = 0.01). Multivariate Cox regression analysis revealed that male sex (HR 2.16, p = 0.04) and positive resection margins (HR 2.31, p = 0.03) were predictors of poor survival whereas surgery was an independent predictor of improved OS (HR 0.321, p < 0.001) CONCLUSIONS: RS is a very rare rectal malignancy with an even poorer prognosis than previously reported. However, undergoing surgery with curative intent while obtaining negative margins may confer better OS.

The Impact of Imatinib on Survival and Treatment Trends for Small Bowel and Colorectal Gastrointestinal Stromal Tumors

BACKGROUND

The aim of this study is to assess treatment trends and overall survival (OS) in small bowel (SB) and colorectal (CR) gastrointestinal stromal tumors (GIST) with respect to the introduction of imatinib in 2008.

METHODS

Patients diagnosed with SB and CR GIST were identified from the National Cancer Database (2004-2015). The primary outcome was 5- and 10-year OS. Patients were stratified by tumor site, time period (before and after imatinib), and treatment type. OS was analyzed using Kaplan-Meier survival curves, log-rank test, and Cox proportional hazards models.

RESULTS

A total of 8441 cases were included (SB 81.66%; CR 18.34%). Radical resection was the most common treatment (SB 42.33%; CR 38.69%). The addition of chemotherapy to radical resection for SB GIST increased between the two time periods (31.76 to 40.43%; p < 0.001), and was associated with improved unadjusted and adjusted OS (2009-2015: adjusted HR [AHR] 0.73, 95% CI 0.59-0.89, p = 0.002). Patients with SB GIST had better 5- and 10-year OS compared with CR (SB 69.83% and 47.68%; CR 61.33% and 45.39%; p < 0.001), even after stratifying by treatment type and tumor size and adjusting for other factors (SB 5-year AHR 1.35, 95% CI 1.19-1.53; 10-year AHR 1.23, 95% CI 1.09-1.38; each p < 0.001).

CONCLUSION

CR GIST are associated with lower OS than SB GIST. Radical resection is the most common treatment type for both sites. Chemotherapy with radical resection offers better OS in SB GIST, but not in CR GIST. Further studies are needed to assess the biology of CR GIST to explain the worse OS.

Leiomyosarcoma of the Rectum as a Radiation-Induced Second Malignancy after Cervical Cancer Treatment: Case Report with Review of the Literature

BACKGROUND

Incidence of cervical cancer among women of reproductive age still remains significantly high. In regard to prognostic features and risk factors, the standard treatment for most types of cervical cancer represents a combination of surgical treatment and radiation therapy, such as external beam radiation therapy and brachytherapy. Despite significant advances of long-term oncological outcomes, radiation-induced secondary malignancies among cervical cancer survivors are still an issue. Current case report describes an incredibly rare case of radiation-induced leiomyosarcoma of the rectum, which occurred 32 years after cervical cancer treatment.

CASE PRESENTATION

A 62-year-old female had a past medical history of FIGO stage IIB cervical cancer (squamous cell carcinoma pT2bN0M0). In 1987, she underwent radical hysterectomy with bilateral iliac lymph node dissection, followed by adjuvant radiation therapy-70 Gy external beam pelvic irradiation followed by 30.5 Gy of brachytherapy. Thirty-two years later, she presented with signs of rectal bleeding. Regarding past medical history, radiologic, endoscopic, and pathologic data, the patient was initially diagnosed with a malignant nonepithelial lower rectal tumor of the unknown origin and staged as mrT3a mrN0 cM0. Total mesorectal excision with complete mesocolic excision and central vascular ligation (CME/CVL) carried by an open approach was carried out. In an attempt to identify the tissue of origin, an immunohistochemistry assay had been performed. Tumor cells showed a high rate of mitotic activity with a 45% rate of Ki-67 expression, positive reaction for desmin, and SMA in all samples. Negative reaction for CD117 and S100 was observed. As a conclusion, the immunophenotype was identified as a grade 3 leiomyosarcoma (ISD-code 8890/3).

CONCLUSIONS

We suggest that up to date, radical surgery with curative intent, as it was performed in our study, is the most evidence-based treatment option for patients with radiation-induced sarcomas of the rectum.

Outcomes of Primary Colorectal Sarcoma: A National Cancer Data Base (NCDB) Review

INTRODUCTION

Primary colorectal sarcomas are a rare entity with anecdotally poor outcomes. We sought to inform surgeons, oncologists, and researchers of the characteristics and outcomes of these understudied and difficult-to-manage tumors.

METHODS

The National Cancer Data Base (NCDB) was queried for patients with pathologically confirmed primary sarcoma of the colon or rectum (1998-2012). Gastrointestinal stromal tumors were excluded. Unadjusted overall survival was reported using the Kaplan-Meier method. Patients with colorectal adenocarcinoma were used as a comparison cohort.

RESULTS

Four hundred thirty-three patients with primary colorectal sarcoma were identified (57.5% leiomyosarcoma subtype). Median age was 63 [inter-quartile range 52, 75] years with 23.1% between the ages of 18 and 50 and 48.7% female. Majority of sarcomas were located in the colon (70.7%). When compared to 696,902 patients with adenocarcinoma, sarcoma patients were younger, had larger tumors, were more likely node negative and rectal in location, and higher grade (all p < 0.001), while sex, race, and comorbidity score were similar (all p > 0.05). Overall survival was lower at 5 years in patients with sarcoma (43.8%) than adenocarcinoma (52.3%, p < 0.001).

CONCLUSION

Primary colorectal sarcomas are rare and present at a younger age and higher grade than adenocarcinoma of the colon and rectum. Survival is significantly worse compared to adenocarcinoma patients.

Leiomyosarcoma of the Anus

Six cases of leiomyosarcoma arising in the anus were analyzed both clinicopathologi cally and immunohistochemically. All patients were women, and the mean age was 57 years. The tumors were classified according to the predominant histologic features: two were well and four were moderately differentiated. No poorly differentiated or dedifferentiated areas were recognized. Epithelioid features were seen in parts of all cases. The number of mitoses per 10 high-power fields (HPF) ( x 400) were 1 and 2 in one case each and 4-9 in four cases. Immunohistochemically, all the tumors were positive for muscle-specific actin (HHF35). Alpha smooth muscle actin and desmin were positive in three and four cases, respectively. Two of the six cases died of the disease. Three of the four cases with high mitotic figures (four or more per 10 HPF) either died of the disease or had a local recurrence. These findings suggest that many anal leiomyosarcomas may immunohistochemically and histologically belong to the differentiated type, while the mitotic rate may be an important prognostic factor. Int J Surg Pathol 1(4):221-226, 1994

Liver resection for metastatic colorectal leiomyosarcoma: a single center experience

BACKGROUND

Leiomyosarcoma arising in the colorectum is a rare malignancy of the smooth muscles accounting for less than 1% of gastrointestinal tumors. Surgery remains the most accepted modality for the treatment of this entity however management of liver metastases remains controversial.

METHODS & RESULTS

From 1998 to 2009, five patients diagnosed with primary leiomyosarcoma of colorectal origin with metastatic liver disease, underwent liver resections at the American University of Beirut Medical Center. The median overall survival was 47 months (range, 7-135 months).

CONCLUSIONS

Leiomyosarcoma of colorectal origin with liver metastasis is a very rare entity. Long-term survival can be achieved after surgical resection and should be considered for all patients.

Soft tissue tumors of the anorectum: rare, complex and misunderstood

Anorectal soft tissue tumors are uncommon and often present both diagnostic and therapeutic challenges. Although many of these tumors are identified with imaging performed for unrelated reasons, most present with nonspecific symptoms that can lead to a delay in diagnosis. Historically, radical surgery (abdominoperineal resection) has been the mainstay of treatment for both benign and malignant anorectal soft tissue tumors. However, a lack of proven benefit in benign disease along with changes in technology has called this practice into question. In addition, the role of radiation and/or chemotherapy remains controversial. In this manuscript, we review the history and current status of anorectal soft tissue tumor management, with a particular focus on challenges in optimizing survival.

Leiomiossarcoma perineal: relato de caso e revisão da literatura

Lemiossarcomas são neoplasias malignas que se originam no músculo liso. Quando presentes na região perineal são agressivos e o tratamento cirúrgico mais adequado ainda não está bem definido. Os autores relatam o caso de uma paciente jovem, sexo feminino, com sintomatologia de nodulação perineal há oito meses. Ao exame físico apresentava abaulamento em região perineal esquerda, onde palpava-se massa fibroelástica de aproximadamente 10 cm de diâmetro. Ressonância nuclear magnética mostrava volumosa formação sólida de contornos regulares em região perineal à esquerda sem sinais de infiltração perilesional. O tratamento realizado foi a excisão com margens amplas. A paciente encontra-se em acompanhamento ambulatorial, sem sinais de recidiva local.

Leiomyosarcoma of the Anal Canal: Case Report and Review of the Literature

A rare case of a leiomyosarcoma of the anal canal is presented. A 68-year-old male presented with painful defecation and rectal bleeding. Endorectal ultrasound revealed a mass invading both sphincters (T4 lesion), and extending 6 cm into the anal canal. Colonoscopy revealed an ulcerated area in the anal canal, of which biopsies revealed high-grade leiomyosarcoma–only the eighteenth such case at the time of this submission. The details of the case and teaching images are presented in detail, as is a comprehensive review of the relevant literature.

Leiomyosarcoma of the anal canal: A case report

BACKGROUND

Leiomyosarcoma (LMS) of the colon, rectum, and anus comprise less than 0.1% of all rectal malignancies with isolated leiomyosarcomas of the anal canal representing only eight reported cases. We report one more case and a review of the world literature.

CASE REPORT

An 80-year-old male presented with a complaint of bright red blood per rectum, constipation, and a subjective history of a rectal mass diagnosed 3 years prior. Pertinent findings on physical exam included a hard, non-mobile mass in the anus which biopsy showed to be a LMS. The patient only wished to have a local excision of the mass performed. At the time of operation the perianal mass extended from the external sphincters into the anal canal. The mass was excised with clean margins. The patient refused adjuvant therapy. Approximately 7 months later, the patient was found to have a local recurrence. At this time the patient opted for local excision and radiotherapy.

CONCLUSION

Isolated LMS of the anus is an extremely rare finding with only eight previous reports in the world literature. LMS is an aggressive tumor with a high local recurrence rate as well as significant hematogenous spread. Due to its rarity, there is insufficient data regarding the optimal treatment. Our literature review has displayed some limited preference for radical surgery over local excision, which may in turn lead to a better outcome.

Interstitial nephritis secondary to bevacizumab treatment in metastatic leiomyosarcoma

OBJECTIVE

To report a case of interstitial nephritis associated with the administration of bevacizumab.

CASE SUMMARY

A 26-year-old man diagnosed with metastatic rectal leiomyosarcoma was treated with intravenous bevacizumab 5 mg/kg and received a total of 3 doses at 2 week intervals. His creatinine had increased from 1.0 mg/dL at baseline to 1.6 mg/dL after 2 doses of bevacizumab and to 4.7 mg/dL after the third dose, prompting admission. Acute renal failure was diagnosed, and hemodialysis was initiated. A renal biopsy revealed interstitial nephritis. Renal failure resolved with cessation of the drug, and the patient did not require further hemodialysis.

DISCUSSION

Bevacizumab is a recombinant humanized monoclonal immunoglobulin G antibody to vascular endothelial growth factor. Bevacizumab has shown efficacy in treatment of patients with renal cell carcinoma and colorectal cancer and has been approved by the Food and Drug Administration as a first-line treatment for metastatic colorectal cancer. Our patient had no other confounding factors that might have caused renal failure. The presence of primary glomerular disease was excluded by biopsy. According to the Naranjo probability scale, bevacizumab was the probable cause of acute renal failure in this patient.

CONCLUSIONS

Bevacizumab can cause acute renal failure by inducing interstitial nephritis. Renal function should be monitored during bevacizumab therapy.

Management of Less Common Tumors of the Colon, Rectum, and Anus

The majority of colorectal and anal malignancies are adenocarcinomas and squamous cell cancers, respectively. Despite the predominance of these neoplasms in these locations, rare histiotypes of the colon, rectum, and anus do occur. These histotypes include but are not limited to lymphoma, melanoma, diffuse cavernous hemangioma, and sarcomas, such as leiomyosarcoma or Kaposi's sarcoma. These tumors often present challenges to clinicians with respect to diagnosis, staging, management, and pathology because of their unfamiliarity. A Medline search using "colon," "rectum,""anus," "lymphoma," "melanoma," "diffuse cavernous hemangioma," "squamous cell carcinoma," "carcinoid," "sarcoma," "leiomyosarcoma," "Kaposi's sarcoma," "Paget's disease," "Bowen's disease," and "basal cell carcinoma" as key words was performed as well as a cross-referencing of the bibliography cited in each work. Rare tumors of the colon, rectum, and anus present diagnostic and management dilemmas for clinicians. Because of their infrequency and poor prognosis, the optimal management of these tumors is controversial. For some histotypes, such as squamous cell carcinoma and carcinoids of the rectum, treatment depends on location and size of the tumor. For uncommon anal lesions, such as Bowen's disease, Paget's disease, and basal cell carcinoma, wide local excision (WLE) with negative margins is the standard of care. For other lesions such as anorectal melanoma or leiomyosarcoma, abdominal perineal resection versus WLE is still being debated. Because the optimal treatment of these tumors is still unclear, we recommend a multidisciplinary approach including a surgeon, primary care physician, medical oncologist, radiation oncologist, and pathologist to offer the patient the best outcome.

Evaluation of prognosis for malignant rectal gastrointestinal stromal tumor by clinical parameters and immunohistochemical staining

PURPOSE

The aim of this study was to identify associated prognostic factors influencing the outcome of curative resection of rectal gastrointestinal stromal tumor.

PATIENTS AND METHODS

Diagnostic immunohistochemical staining with CD34, CD117, S-100, desmin, and muscle-specific actin was performed in 46 consecutive patients with previously diagnosed rectal leiomyosarcoma who underwent curative resection from 1979 to 1999. CD44, Bcl-2, P53, and Ki-67 staining were performed on tumors rediagnosed as gastrointestinal stromal tumor for the prognostic evaluation.

RESULTS

There were 42 (91.3 percent) patients with rectal gastrointestinal stromal tumor (18 females and 24 males; mean age, 58.4 years). Twenty-nine patients underwent radical surgical resections, such as abdominoperineal resection or low anterior resection, whereas the other 13 patients underwent wide local excision, such as transrectal excision or Kraske's operation. Sixteen tumors were classified as high-grade gastrointestinal stromal tumors, and 26 as low-grade. No tumor had a positive P53 stain. Twenty-seven patients (64.3 percent) developed recurrence or metastasis postoperatively (median follow-up, 52 months). The one-year, two-year, and five-year disease-free survival rates were 90.2 percent, 76.7 percent, and 43.9 percent, respectively. Of these patients with recurrence, subsequent resections in 12 patients with local recurrence, transarterial tumor embolism or STI-571 chemotherapies in 3 patients with distant mestastases were performed. The one-year, two-year, and five-year overall survival rates were 97.4 percent, 94.3 percent, and 83.7 percent, respectively. Bcl-2 (P = 0.007) and histologic grade (P = 0.05) in disease-free survival analysis and age < 50 years (P = 0.03) and tumor size > 5 cm (P = 0.02) in overall survival analysis were independent prognostic factors. The group with wide local excision had a higher local recurrence rate than that of the radical resection group (77 percent vs. 31 percent, P = 0.006), despite smaller tumors (4.5 vs. 7.2 cm, P = 0.05). There was no difference in the incidence of distant metastasis between the two groups.

CONCLUSION

Younger age (< 50 years), higher histologic tumor grade, positive Bcl-2 status, and larger tumors (> 5 cm) were factors associated with significantly poorer prognoses for rectal gastrointestinal stromal tumor. Radical resection was superior to wide local excision in the prevention of local recurrence, but not that of distant metastases.

Surgical outcome after curative resection of rectal leiomyosarcoma

PURPOSE

The aim of this study is to present the prognosis and possible associated prognostic factors after curative resection of rectal leiomyosarcoma.

METHODS

From 1979 to 1996 our hospital saw 40 patients with rectal leiomyosarcoma, including 19 females, who did not have metastasis initially and received curative resection and regular postoperative follow-up.

RESULTS

The mean age of the 40 patients was 58.7 years. Anal bleeding and perianal pain were the two most common symptoms at initial diagnosis. Twenty-nine patients received a radical surgical resection, such as abdominoperineal resection or low anterior resection; the other 11 patients received a wide local excision, such as transrectal excision or Kraske's operation. Sixteen tumors were classified as high-grade leiomyosarcoma, and 23 as low grade. Nineteen patients (48 percent) developed recurrence or metastasis postoperatively (median follow-up, 35 months). The overall and disease-free (1-year, 3-year, and 5-year) survival rates were 97, 90, and 75 percent and 90, 59, and 46 percent, respectively. In univariate analysis, younger group (<50 years, n = 9, P = 0.033) and high-grade leiomyosarcoma (P = 0.043) showed poorer prognosis in the disease-free survival curve. In the multivariate Cox model, gender, tumor size, tumor location, and operation type did not significantly affect disease-free survival, whereas histologic grade (P = 0.037) and age divided by a level of 50 years (P = 0.009) were shown to be independent factors. There was a strong trend toward higher local recurrence rate for the wide local excision group than for the radical resection group (55 vs. 24 percent, P = 0.067) despite the wide local excision group being composed of smaller tumors (5.1 vs. 7.5 cm, P = 0.069). There was no difference in the incidence of distant metastasis between the two groups with different operation types. The metastasis rates of the wide local excision and radical resection groups were 27 and 38 percent, respectively.

CONCLUSION

A younger age (<50 years) and a high histologic grade of tumor were the two most significant poor prognostic factors for rectal leiomyosarcoma. Radical resection may be superior to wide local excision in the prevention of local recurrence but not distant metastasis.

Malignant stromal tumour of the rectum: findings at endorectal ultrasound and MRI

This case report describes the findings on endorectal ultrasound and MRI in a patient with a giant malignant stromal tumour of the rectum. A review of imaging characteristics and histopathological findings as described in the literature is presented.

Benefits of endorectal ultrasound for management of smooth-muscle tumor of the rectum: report of three cases

Smooth-muscle tumor of the rectum is rare, and the therapeutic strategy is still controversial. Endorectal ultrasound was used to evaluate three patients with smooth-muscle tumor of the rectum. Endorectal ultrasound demonstrated a homogenous hypoechoic tumor without invasion to the perirectal tissue in two patients. The tumor was 5 cm in diameter in one patient and 4 cm in diameter in the other patient, and they were excised locally. Their histologic types were leiomyoma and leiomyosarcoma. The third patient had a recurrent leiomyosarcoma. Proctosigmoidoscopy found a linear lesion with ulcerated mucosa on the rectal wall. Endorectal ultrasound observed a hypoechoic solid tumor of 3.5 cm x 1 cm, which involved the mucosal, submucosal, and muscle layers of the rectal wall. Disruption of the first hypoechoic layer was identified. Abdominoperineal resection was performed. Endorectal ultrasound follow-up revealed no evidence of recurrence in any of these patients. Endorectal ultrasound can help to define the extent of disease and may be a useful adjunct in deciding about the appropriate surgical procedure in these diseases.

Perineal and perirectal sarcomas: report of two cases

PURPOSE

Perineal sarcomas are rare tumors that are typically of an extensive nature by the time of diagnosis. In this article, two case reports are followed by a brief review of different types of sarcomas that may occur in the perineal and perirectal region.

STUDY PATIENTS

This study consists of two cases that are representative of the many types of perineal/perirectal sarcomas.

PRINCIPLE CONCLUSIONS

Perineal and perirectal sarcomas are generally of poor prognosis mainly because of delayed diagnosis. Computed tomography and magnetic resonance imaging can be extremely useful to help assess these tumors. It is well known that the most important criterion for diagnosing leiomyosarcomas appears to be the presence of mitotic activity. Anorectal stromal tumors having five or more mitoses per 50 high powered fields are considered to be malignant. The mainstay of treatment is surgical excision with wide margins. Currently, chemotherapeutic and radiotherapy trials are under way.

Endorectal ultrasound and leiomyosarcoma of the rectum

Leiomyosarcomas of the rectum are uncommon neoplasms accounting for fewer than 1% of all malignancies of the colon and rectum. Approximately 215 cases have been described in the literature. Distinction from leiomyoma is often difficult, but regarding dignity is important. The case reported is that of a 68-year-old man in whom a 2.2-cm rectal mass covered by mucosa was diagnosed by rectoscopy and endorectal ultrasound. After treatment by wide local excision the histological specimen revealed a low-grade, highly differentiated leiomyosarcoma. Due to the lack of a large series of this disease, there is disagreement over the therapeutic strategy. At the moment a selective treatment approach seems to be the most frequently advocated. Large tumors and those extending beyond the rectal wall are treated by radical surgical resection. Leiomyosarcomas less than 2.5 cm in size and confined to the bowel wall can be treated by wide local excision. Endosonography can provide exact assessment of tumor size and expansion and is of great value in selecting the appropriate treatment.

Leiomyosarcoma of the rectum and anal canal

Leiomyosarcoma of the rectum and anal canal is rare and the optimal treatment is not clear. Eight patients with isolated anorectal leiomyosarcoma treated surgically were reviewed. The age ranged from 44 to 76 years (median 63 years) and the follow up ranged from 6 months to 4.5 years (median 2 years). All patients were symptomatic at presentation. All tumours involved the muscularis propria of the low and/or mid-rectum with three tumours also involving the anal sphincters. The tumour size ranged from 1.2 to 10 cm (median 4 cm). Mucosal involvement occurred in only three patients and there was no lymph node involvement. All showed microscopic infiltration at the advancing border, despite macroscopic circumscription. Only one patient was thought to have a tumour sufficiently small (3 cm) and localized on clinical and intrarectal ultrasound examinations (UST2N0) to be suitable for wide local excision. That patient remained tumour-free after 2 years. The remaining patients (88%) were treated by abdomino-perineal resection. The disease free interval in this latter group ranged from 3 months to 4.5 years. All recurrences were detected within 15 months of surgery and the mean interval from detection of recurrence to death was 9 months. Using a histological grading system that included tumour differentiation, mitotic count and amount of necrosis, high grade sarcomas were associated with a worse prognosis. Other factors associated with a poor outcome included large tumour size (> 6-7 cm) and prior incomplete local excision.