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PENILE AGENESIS WITH A SEPARATED SCROTUM AND NORMAL RENAL FUNCTION IN AN IDENTICAL TWIN
0022-5347/02/1672-0687/0 THE JOURNAL OF UROLOGY® Copyright © 2002 by AMERICAN UROLOGICAL ASSOCIATION, INC.®
Vol. 167, 687– 688, February 2002 Printed in U.S.A.
PENILE AGENESIS WITH A SEPARATED SCROTUM AND NORMAL RENAL FUNCTION IN AN IDENTICAL TWIN JUSTIN E. WITTKOPF, CHRISTOPHER S. COOPER
AND
CHARLES E. HAWTREY
From the Children’s Hospital of Iowa, Division of Pediatric Urology, Iowa City, Iowa KEY WORDS: penis, abnormalities, twins, scrotum
Penile agenesis is a rare malformation with an incidence of 1/10 to 30 million live births. Fewer than 100 reported cases exist. In previous cases of penile agenesis renal function was often compromised and the scrotum was usually located in the midline. We report a twin with penile agenesis, a completely separated hemiscrotum, normal renal function and an unaffected co-twin. CASE REPORT
Our patient was the product of a 32-week twin gestation of a 17-year-old G1P1 white female. There was no history of exposure to toxic substances and each twin was in clinically stable condition after birth. Physical examination demonstrated an imperforate anus, split hemiscrotum with palpable testicles and no phallus in the patient (fig. 1). Stool and urine were draining at the umbilicus. Renal ultrasound revealed crossed renal ectopia with the left kidney residing in the right pelvis and no evidence of cortical cysts or hydronephrosis. Serum follicle-stimulating hormone, luteinizing hormone and testosterone were within normal limits. The karyotype was 46 XY. On day 2 of life exploratory laparotomy revealed persistent Accepted for publication September 28, 2001.
FIG. 1. Widely split hemiscrotum and penile agenesis
cloaca, which was separated to create a colostomy with mucus fistula and a midline vesicostomy. Magnetic resonance imaging showed hemivertebrae, a tethered cord, lipoma and syrinx at the L3 to L4 level. No penile corporeal bodies were identified. At age 1 year the patient underwent surgery for partial bladder prolapse. After the prolapsed bladder was reduced and the vesicostomy was revised the bilateral hemiscrotum was joined in the midline (fig. 2). The corporeal bodies were sought within the perineum and bladder during dissection but were not present. The patient did well postoperatively. Serum creatinine was 0.4 gm./dl. at age 15 months. We plan future formation of an abdominal continent catheterizable stoma and subsequent phallic reconstruction. DISCUSSION
Penile agenesis is rare and often occurs with other associated abnormalities, including renal, vertebral, urethral, scrotal and anal malformation. The coexistence of these phenomena has been attributed to regression of the caudal mesoderm during embryogenesis.1–3 The penis, bladder and hindgut develop from the mesoderm at approximately 5 to 7 weeks of gestation. Alternatively the scrotum develops from the ectoderm. Major disruptions at this time result in the associations typically observed with penile agenesis. Magnetic res-
FIG. 2. View immediately postoperatively shows hemiscrotum joined at midline. 687
688
PENILE AGENESIS IN IDENTICAL TWIN
onance imaging may be useful for defining anatomical variations and detecting erectile tissue.1 Our patient is 1 of 4 known twins with penile agenesis and a normal co-twin. The 3 cases previously reported by Berry,2 Evans3 and Koffler4 et al, respectively, involved significant renal dysplasia-aplasia. Unlike all previously reported twins with penile agenesis our patient has normal renal function, although with an ectopic kidney. Penile agenesis is typically associated with a midline scrotum that may not have a raphe due to the embryological absence of a cloacal membrane. Berry et al noted a direct association of renal function with a scrotal raphe in cases of penile agenesis.2 Uniquely our patient had a widely separated hemiscrotum, which to our knowledge has not been previously reported. In addition, he was of twin gestation and had normal renal function. It remains difficult to explain
what factors led to the preservation of renal function in our patient or the factors that so discrepantly affected these twins. REFERENCES
1. Glu¨ er, S., Fuchs, J. and Mildenberger, H.: Diagnosis and current management of penile agenesis. J Pediatr Surg, 33: 628, 1998 2. Berry, S. A., Johnson, D. E. and Thompson, T. R.: Agenesis of the penis, scrotal raphe and anus in one of monoamniotic twins. Teratology, 29: 173, 1984 3. Evans, J. A., Lawrence, B. E., Greenberg, C. R. et al: Agenesis of the penis: patterns of associated malformations. Am J Med Genet, 84: 47, 1999 4. Koffler, H., Aase, J. M., Papile, L. A. et al: Persistent cloaca with absent penis and anal atresia in one of identical twins. J Pediatr, 93: 821, 1978
Vol. 167, 687– 688, February 2002 Printed in U.S.A.
PENILE AGENESIS WITH A SEPARATED SCROTUM AND NORMAL RENAL FUNCTION IN AN IDENTICAL TWIN JUSTIN E. WITTKOPF, CHRISTOPHER S. COOPER
AND
CHARLES E. HAWTREY
From the Children’s Hospital of Iowa, Division of Pediatric Urology, Iowa City, Iowa KEY WORDS: penis, abnormalities, twins, scrotum
Penile agenesis is a rare malformation with an incidence of 1/10 to 30 million live births. Fewer than 100 reported cases exist. In previous cases of penile agenesis renal function was often compromised and the scrotum was usually located in the midline. We report a twin with penile agenesis, a completely separated hemiscrotum, normal renal function and an unaffected co-twin. CASE REPORT
Our patient was the product of a 32-week twin gestation of a 17-year-old G1P1 white female. There was no history of exposure to toxic substances and each twin was in clinically stable condition after birth. Physical examination demonstrated an imperforate anus, split hemiscrotum with palpable testicles and no phallus in the patient (fig. 1). Stool and urine were draining at the umbilicus. Renal ultrasound revealed crossed renal ectopia with the left kidney residing in the right pelvis and no evidence of cortical cysts or hydronephrosis. Serum follicle-stimulating hormone, luteinizing hormone and testosterone were within normal limits. The karyotype was 46 XY. On day 2 of life exploratory laparotomy revealed persistent Accepted for publication September 28, 2001.
FIG. 1. Widely split hemiscrotum and penile agenesis
cloaca, which was separated to create a colostomy with mucus fistula and a midline vesicostomy. Magnetic resonance imaging showed hemivertebrae, a tethered cord, lipoma and syrinx at the L3 to L4 level. No penile corporeal bodies were identified. At age 1 year the patient underwent surgery for partial bladder prolapse. After the prolapsed bladder was reduced and the vesicostomy was revised the bilateral hemiscrotum was joined in the midline (fig. 2). The corporeal bodies were sought within the perineum and bladder during dissection but were not present. The patient did well postoperatively. Serum creatinine was 0.4 gm./dl. at age 15 months. We plan future formation of an abdominal continent catheterizable stoma and subsequent phallic reconstruction. DISCUSSION
Penile agenesis is rare and often occurs with other associated abnormalities, including renal, vertebral, urethral, scrotal and anal malformation. The coexistence of these phenomena has been attributed to regression of the caudal mesoderm during embryogenesis.1–3 The penis, bladder and hindgut develop from the mesoderm at approximately 5 to 7 weeks of gestation. Alternatively the scrotum develops from the ectoderm. Major disruptions at this time result in the associations typically observed with penile agenesis. Magnetic res-
FIG. 2. View immediately postoperatively shows hemiscrotum joined at midline. 687
688
PENILE AGENESIS IN IDENTICAL TWIN
onance imaging may be useful for defining anatomical variations and detecting erectile tissue.1 Our patient is 1 of 4 known twins with penile agenesis and a normal co-twin. The 3 cases previously reported by Berry,2 Evans3 and Koffler4 et al, respectively, involved significant renal dysplasia-aplasia. Unlike all previously reported twins with penile agenesis our patient has normal renal function, although with an ectopic kidney. Penile agenesis is typically associated with a midline scrotum that may not have a raphe due to the embryological absence of a cloacal membrane. Berry et al noted a direct association of renal function with a scrotal raphe in cases of penile agenesis.2 Uniquely our patient had a widely separated hemiscrotum, which to our knowledge has not been previously reported. In addition, he was of twin gestation and had normal renal function. It remains difficult to explain
what factors led to the preservation of renal function in our patient or the factors that so discrepantly affected these twins. REFERENCES
1. Glu¨ er, S., Fuchs, J. and Mildenberger, H.: Diagnosis and current management of penile agenesis. J Pediatr Surg, 33: 628, 1998 2. Berry, S. A., Johnson, D. E. and Thompson, T. R.: Agenesis of the penis, scrotal raphe and anus in one of monoamniotic twins. Teratology, 29: 173, 1984 3. Evans, J. A., Lawrence, B. E., Greenberg, C. R. et al: Agenesis of the penis: patterns of associated malformations. Am J Med Genet, 84: 47, 1999 4. Koffler, H., Aase, J. M., Papile, L. A. et al: Persistent cloaca with absent penis and anal atresia in one of identical twins. J Pediatr, 93: 821, 1978