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Anal canal duplication associated with presacral cyst
Journal of Pediatric Surgery (2008) 43, 1749–1752
www.elsevier.com/locate/jpedsurg
Anal canal duplication associated with presacral cyst Johannes R. Kratz a , Vikram Deshpande b , Daniel P. Ryan c , Allan M. Goldstein c,⁎ a
Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA c Department of Pediatric Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA b
Received 31 March 2008; revised 13 May 2008; accepted 13 May 2008
Key words: Anal canal duplication; Presacral cyst
Abstract Anal canal duplications are rare congenital malformations, with fewer than 50 reported cases in the literature. Anal canal duplications are noncommunicating second anal orifices located posterior to the true anus without other associated hindgut duplications. Typically, these are asymptomatic, tubular malformations that present in females before the age of 6 years. Here, we report on a 16-year-old girl with a symptomatic anal canal duplication associated with a presacral cystic component. This is an unusual presentation of an already rare entity. An overview of the clinical presentation, radiologic workup, surgical treatment, and histologic features of anal canal duplications is provided. © 2008 Elsevier Inc. All rights reserved.
Duplication of the anal canal is a rare congenital malformation, with fewer than 50 reported cases in the English-language literature since 1956. Anal canal duplications are defined as second anal orifices located posterior to the true anus, ending blindly without connection to the rectum, and containing histologic features of a true anal canal, including squamous epithelium at the distal end and smooth muscle cells and anal glands in the wall of the canal [1-3]. This definition differentiates anal duplications from rectal cyst duplications, which are cystic structures communicating with the rectum [4], and hindgut duplications, which include additional structures such as the rectum or colon [2]. A variety of approaches to the diagnosis and treatment of anal canal duplications have been described. We report here on a case of anal duplication in a 16-year-old girl and review the clinical and diagnostic features of this rare anomaly.
⁎ Corresponding author. Tel.: +1 617 726 0270; fax: +1 617 726 2167. E-mail address: [email protected] (A.M. Goldstein). 0022-3468/$ – see front matter © 2008 Elsevier Inc. All rights reserved. doi:10.1016/j.jpedsurg.2008.05.026
1. Case A 16-year-old girl was referred for evaluation of a cystic mass in the pelvis. She was well until 5 months prior to presentation when she began to experience intermittent dull bilateral lower abdominal pain. Review of systems was negative for nausea, vomiting, diarrhea, constipation, intestinal bleeding, or mucous discharge. Her past medical history was unremarkable. She was initially evaluated by pelvic ultrasound and diagnosed with an ovarian cyst, which was felt to be the cause of her symptoms. Laparoscopy revealed normal ovaries. However, fullness in the pelvis below the peritoneal reflection was noted, and the patient was referred to pediatric surgery. Magnetic resonance imaging (MRI) revealed a presacral cyst posterior to the rectum (Fig. 1A). The patient was taken to the operating room for resection of this mass. She was placed in the prone position, and a posterior sagittal approach was used. A small, second anal opening, located approximately 1 cm posterior to the true anus, was identified (Fig. 1B). This second anal orifice was dissected circumferentially and found to communicate
1750
J.R. Kratz et al.
Fig. 1 Radiographic and intraoperative images. Midsagittal T2-weighted MRI shows presacral cystic mass (A, arrow). Intraoperatively, with the patient prone and a dilator in the anus, a second anal orifice (arrow) is seen 1 cm posterior to the true anus (B, arrow). A posterior sagittal approach, with the tip of the coccyx removed (C, arrow), allows visualization of the presacral cystic mass (C, asterisk).
directly with the presacral cyst (Fig. 1C), which contained a large amount of sebaceous material. The anal opening and canal were removed in continuity with the cyst, which was adjacent to, but separate from, the rectum. Histologic examination demonstrated a 1.0-cm-long duct lined predominantly by squamous epithelium and focally by columnar and transitional epithelium (Fig. 2A). Periluminal anal glands were present. Aggregates of smooth muscle cells were present in the wall of the duct but were disorganized and did not form an organized muscularis propria (Fig. 2B). The lining epithelium and smooth muscle support our hypothesis that this tissue is of anal origin. The duct opened superiorly into a 5.0 × 4.0 × 2.0-cm cyst filled with sebaceous material and lined by mature squamous epithelium. The patient tolerated the procedure well and had an unremarkable postoperative course. She remains well and symptom-free 1 year after the procedure.
2. Discussion Anal duplications are very rare congenital anomalies. First described by Dukes and Galvin in 1956 [5], a number of criteria have been proposed to classify them properly. Based on the criteria established by Ochiai et al [3], anal canal duplications must have 3 characteristics: (1) the caudal end contains squamous epithelium, (2) the cranial end contains transitional epithelium, and (3) smooth muscle cells are found in the wall of the anal canal. Although a number of theories have been proposed, the embryologic origin of anal canal duplications remains unclear. Reported cases share several common themes (Table 1 [1-4], [6-9]). Most patients present before the age of 6 years, at a mean age of 5.4 years. Most are female (86%). Of all anal
Fig. 2 Histologic features of anal canal duplication. Photomicrographs from the distal portion of the specimen show an admixture of squamous (long arrow), columnar (arrowhead), and transitional (short arrow) epithelium (A). Disorganized bundles of smooth muscle are also present (B, arrow).
Anal canal duplication associated with presacral cyst Table 1
1751
Reported cases of anal canal duplication
Age
Sex
Associated malformations
Method of diagnosis
Reference
8 mo 0 mo 0 mo 2y 0 mo 2y 5y 2 mo 3y 1y 3 mo 2y 0 mo 7y 4 mo 4 mo 4 mo 3 mo 3 mo 9 mo 6y 3 mo 1 mo 0 mo 12 y 0 mo 3 mo 12 mo 7 mo 6y 35 y 45 y 11 mo 38 y 16 y
F F F F F F M F F F F F F F F F F F F F F F F F F M F F F F F M M M F
None None None None Cleft lip and palate, omphalocele, genitourinary malformation Intestinal neuronal dysplasia, presacral ependymoma None Vestibular fistula None Presacral teratoma Presacral teratoma None None Intrasacral meningocele None None None None None None Presacral mass Presacral teratoma None None Ureteric duplication Intestinal malrotation Presacral teratoma, lumbrosacral meningocele None None Cleft lip None None Ventricular septal defect None Presacral cyst
Fistulogram Fistulogram Fistulogram Fistulogram Fistulogram MRI MRI MRI MRI MRI Ultrasound Ultrasound Fistulogram Fistulogram Fistulogram, Ultrasound Fistulogram, Ultrasound CT CT, fistulogram None CT, fistulogram CT, fistulogram Fistulogram Fistulogram Fistulogram Fistulogram Fistulogram Fistulogram, Ultrasound, MRI Fistulogram Fistulogram, MRI Fistulogram, MRI Fistulogram None None None MRI
[9]
[4] [1]
[3] [6]
[7] [2] [8]
Current
F indicates female; M, male.
canal duplications, 37% are associated with other anomalies, including teratomas, cleft lip or palate, intestinal malrotation, and meningocele. Most of the patients are asymptomatic (60%). Mild symptoms, such as constipation or mucous discharge, occur in 20%, and more severe symptoms, such as recurrent fistulas, pain, or inflammation, occur in the remainder. The severity of these symptoms correlates with the age at presentation. Asymptomatic patients have a mean age of presentation of 7 months, whereas the mean age of patients presenting with mild or severe symptoms is 5.5 and 19.5 years, respectively. Most anal canal duplications are tubular in nature (89%), although they occasionally occur with a cystic component (11%), as in our case. All reported cases have been found either at the level of, or posterior to, the anus, with most presenting along the posterior midline (83%) [6,7]. The diagnosis and treatment of anal canal duplications are variable. Fistulograms can be used for diagnosis,
although MRI, computed tomography (CT), and ultrasound have all been used successfully. Physical examination alone may be sufficient, especially in adult patients. Anal canal duplications are most often treated by total excision of the tract, using either a perineal [2,6,8,9] or posterior sagittal [1,9] approach, although Tiryaki et al [4] described simple mucosal stripping. Because these lesions contain anal glands, secretions may build up in the duct leading to recurrent infections and subsequent widening of the anal orifice from repeated incision and drainage procedures [1]. Although multiple authors have recommended excision of anal canal duplications based on their long-term risk of malignancy [2-4], that risk has only been reported once, in an article from 1956, where colloid carcinomas were observed in 8 out of 10 adult cases [5]. No additional cases of malignancy have been described. Long-term follow-up of patients with these rare entities is needed.
1752
References [1] Choi SO, Park WH. Anal canal duplication in infants. J Pediatr Surg 2003;38:758-62. [2] Hamada Y, Sato M, Hioki K. Anal canal duplication in childhood. Pediatric Surgery International 1996;11:577-9. [3] Ochiai K, Umeda T, Murahashi O, et al. Anal-Canal duplication in a 6year-old child. Pediatr Surg Int 2002;18:195-7. [4] Tiryaki T, Senel E, Atayurt H. Anal canal duplication in children: a new technique. Pediatr Surg Int 2006;22:560-1.
J.R. Kratz et al. [5] Dukes CE, Galvin C. Colloid carcinoma arising within fistulae in the anorectal region. Ann R Coll Surg Engl 1956;18:246-61. [6] Arai T, Miyano T, Tanno M, et al. Tubular anal duplication— experiences with two cases. Z Kinderchir 1990;45:311-3. [7] Jacquier C, Dobremez E, Piolat C, et al. Anal canal duplication in infants and children—a series of 6 cases. Eur J Pediatr Surg 2001;11:186-91. [8] Ponson AE, Festen C. Postanal sinus: single or different etiologies? Pediatr Surg Int 2001;17:45-7. [9] Tagart RE. Congenital anal duplication: a cause of para-anal sinus. Br J Surg 1977;64:525-8.
www.elsevier.com/locate/jpedsurg
Anal canal duplication associated with presacral cyst Johannes R. Kratz a , Vikram Deshpande b , Daniel P. Ryan c , Allan M. Goldstein c,⁎ a
Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA c Department of Pediatric Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA b
Received 31 March 2008; revised 13 May 2008; accepted 13 May 2008
Key words: Anal canal duplication; Presacral cyst
Abstract Anal canal duplications are rare congenital malformations, with fewer than 50 reported cases in the literature. Anal canal duplications are noncommunicating second anal orifices located posterior to the true anus without other associated hindgut duplications. Typically, these are asymptomatic, tubular malformations that present in females before the age of 6 years. Here, we report on a 16-year-old girl with a symptomatic anal canal duplication associated with a presacral cystic component. This is an unusual presentation of an already rare entity. An overview of the clinical presentation, radiologic workup, surgical treatment, and histologic features of anal canal duplications is provided. © 2008 Elsevier Inc. All rights reserved.
Duplication of the anal canal is a rare congenital malformation, with fewer than 50 reported cases in the English-language literature since 1956. Anal canal duplications are defined as second anal orifices located posterior to the true anus, ending blindly without connection to the rectum, and containing histologic features of a true anal canal, including squamous epithelium at the distal end and smooth muscle cells and anal glands in the wall of the canal [1-3]. This definition differentiates anal duplications from rectal cyst duplications, which are cystic structures communicating with the rectum [4], and hindgut duplications, which include additional structures such as the rectum or colon [2]. A variety of approaches to the diagnosis and treatment of anal canal duplications have been described. We report here on a case of anal duplication in a 16-year-old girl and review the clinical and diagnostic features of this rare anomaly.
⁎ Corresponding author. Tel.: +1 617 726 0270; fax: +1 617 726 2167. E-mail address: [email protected] (A.M. Goldstein). 0022-3468/$ – see front matter © 2008 Elsevier Inc. All rights reserved. doi:10.1016/j.jpedsurg.2008.05.026
1. Case A 16-year-old girl was referred for evaluation of a cystic mass in the pelvis. She was well until 5 months prior to presentation when she began to experience intermittent dull bilateral lower abdominal pain. Review of systems was negative for nausea, vomiting, diarrhea, constipation, intestinal bleeding, or mucous discharge. Her past medical history was unremarkable. She was initially evaluated by pelvic ultrasound and diagnosed with an ovarian cyst, which was felt to be the cause of her symptoms. Laparoscopy revealed normal ovaries. However, fullness in the pelvis below the peritoneal reflection was noted, and the patient was referred to pediatric surgery. Magnetic resonance imaging (MRI) revealed a presacral cyst posterior to the rectum (Fig. 1A). The patient was taken to the operating room for resection of this mass. She was placed in the prone position, and a posterior sagittal approach was used. A small, second anal opening, located approximately 1 cm posterior to the true anus, was identified (Fig. 1B). This second anal orifice was dissected circumferentially and found to communicate
1750
J.R. Kratz et al.
Fig. 1 Radiographic and intraoperative images. Midsagittal T2-weighted MRI shows presacral cystic mass (A, arrow). Intraoperatively, with the patient prone and a dilator in the anus, a second anal orifice (arrow) is seen 1 cm posterior to the true anus (B, arrow). A posterior sagittal approach, with the tip of the coccyx removed (C, arrow), allows visualization of the presacral cystic mass (C, asterisk).
directly with the presacral cyst (Fig. 1C), which contained a large amount of sebaceous material. The anal opening and canal were removed in continuity with the cyst, which was adjacent to, but separate from, the rectum. Histologic examination demonstrated a 1.0-cm-long duct lined predominantly by squamous epithelium and focally by columnar and transitional epithelium (Fig. 2A). Periluminal anal glands were present. Aggregates of smooth muscle cells were present in the wall of the duct but were disorganized and did not form an organized muscularis propria (Fig. 2B). The lining epithelium and smooth muscle support our hypothesis that this tissue is of anal origin. The duct opened superiorly into a 5.0 × 4.0 × 2.0-cm cyst filled with sebaceous material and lined by mature squamous epithelium. The patient tolerated the procedure well and had an unremarkable postoperative course. She remains well and symptom-free 1 year after the procedure.
2. Discussion Anal duplications are very rare congenital anomalies. First described by Dukes and Galvin in 1956 [5], a number of criteria have been proposed to classify them properly. Based on the criteria established by Ochiai et al [3], anal canal duplications must have 3 characteristics: (1) the caudal end contains squamous epithelium, (2) the cranial end contains transitional epithelium, and (3) smooth muscle cells are found in the wall of the anal canal. Although a number of theories have been proposed, the embryologic origin of anal canal duplications remains unclear. Reported cases share several common themes (Table 1 [1-4], [6-9]). Most patients present before the age of 6 years, at a mean age of 5.4 years. Most are female (86%). Of all anal
Fig. 2 Histologic features of anal canal duplication. Photomicrographs from the distal portion of the specimen show an admixture of squamous (long arrow), columnar (arrowhead), and transitional (short arrow) epithelium (A). Disorganized bundles of smooth muscle are also present (B, arrow).
Anal canal duplication associated with presacral cyst Table 1
1751
Reported cases of anal canal duplication
Age
Sex
Associated malformations
Method of diagnosis
Reference
8 mo 0 mo 0 mo 2y 0 mo 2y 5y 2 mo 3y 1y 3 mo 2y 0 mo 7y 4 mo 4 mo 4 mo 3 mo 3 mo 9 mo 6y 3 mo 1 mo 0 mo 12 y 0 mo 3 mo 12 mo 7 mo 6y 35 y 45 y 11 mo 38 y 16 y
F F F F F F M F F F F F F F F F F F F F F F F F F M F F F F F M M M F
None None None None Cleft lip and palate, omphalocele, genitourinary malformation Intestinal neuronal dysplasia, presacral ependymoma None Vestibular fistula None Presacral teratoma Presacral teratoma None None Intrasacral meningocele None None None None None None Presacral mass Presacral teratoma None None Ureteric duplication Intestinal malrotation Presacral teratoma, lumbrosacral meningocele None None Cleft lip None None Ventricular septal defect None Presacral cyst
Fistulogram Fistulogram Fistulogram Fistulogram Fistulogram MRI MRI MRI MRI MRI Ultrasound Ultrasound Fistulogram Fistulogram Fistulogram, Ultrasound Fistulogram, Ultrasound CT CT, fistulogram None CT, fistulogram CT, fistulogram Fistulogram Fistulogram Fistulogram Fistulogram Fistulogram Fistulogram, Ultrasound, MRI Fistulogram Fistulogram, MRI Fistulogram, MRI Fistulogram None None None MRI
[9]
[4] [1]
[3] [6]
[7] [2] [8]
Current
F indicates female; M, male.
canal duplications, 37% are associated with other anomalies, including teratomas, cleft lip or palate, intestinal malrotation, and meningocele. Most of the patients are asymptomatic (60%). Mild symptoms, such as constipation or mucous discharge, occur in 20%, and more severe symptoms, such as recurrent fistulas, pain, or inflammation, occur in the remainder. The severity of these symptoms correlates with the age at presentation. Asymptomatic patients have a mean age of presentation of 7 months, whereas the mean age of patients presenting with mild or severe symptoms is 5.5 and 19.5 years, respectively. Most anal canal duplications are tubular in nature (89%), although they occasionally occur with a cystic component (11%), as in our case. All reported cases have been found either at the level of, or posterior to, the anus, with most presenting along the posterior midline (83%) [6,7]. The diagnosis and treatment of anal canal duplications are variable. Fistulograms can be used for diagnosis,
although MRI, computed tomography (CT), and ultrasound have all been used successfully. Physical examination alone may be sufficient, especially in adult patients. Anal canal duplications are most often treated by total excision of the tract, using either a perineal [2,6,8,9] or posterior sagittal [1,9] approach, although Tiryaki et al [4] described simple mucosal stripping. Because these lesions contain anal glands, secretions may build up in the duct leading to recurrent infections and subsequent widening of the anal orifice from repeated incision and drainage procedures [1]. Although multiple authors have recommended excision of anal canal duplications based on their long-term risk of malignancy [2-4], that risk has only been reported once, in an article from 1956, where colloid carcinomas were observed in 8 out of 10 adult cases [5]. No additional cases of malignancy have been described. Long-term follow-up of patients with these rare entities is needed.
1752
References [1] Choi SO, Park WH. Anal canal duplication in infants. J Pediatr Surg 2003;38:758-62. [2] Hamada Y, Sato M, Hioki K. Anal canal duplication in childhood. Pediatric Surgery International 1996;11:577-9. [3] Ochiai K, Umeda T, Murahashi O, et al. Anal-Canal duplication in a 6year-old child. Pediatr Surg Int 2002;18:195-7. [4] Tiryaki T, Senel E, Atayurt H. Anal canal duplication in children: a new technique. Pediatr Surg Int 2006;22:560-1.
J.R. Kratz et al. [5] Dukes CE, Galvin C. Colloid carcinoma arising within fistulae in the anorectal region. Ann R Coll Surg Engl 1956;18:246-61. [6] Arai T, Miyano T, Tanno M, et al. Tubular anal duplication— experiences with two cases. Z Kinderchir 1990;45:311-3. [7] Jacquier C, Dobremez E, Piolat C, et al. Anal canal duplication in infants and children—a series of 6 cases. Eur J Pediatr Surg 2001;11:186-91. [8] Ponson AE, Festen C. Postanal sinus: single or different etiologies? Pediatr Surg Int 2001;17:45-7. [9] Tagart RE. Congenital anal duplication: a cause of para-anal sinus. Br J Surg 1977;64:525-8.