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Meconium periorchitis presenting as scrotal masses
CASE REPORT
MECONIUM PERIORCHITIS PRESENTING AS SCROTAL MASSES BARRY CHANG
AND
LANE S. PALMER
ABSTRACT Meconium periorchitis results from calcified meconium trapped in the scrotum and often mimics a testicular malignancy in an infant. Inguinal exploration is warranted if definitive diagnosis cannot be obtained from radiologic evaluations. Magnetic resonance imaging may be helpful in cases in which the scrotal ultrasound findings are inconclusive. UROLOGY 59: 296vii–296ix, 2002. © 2002, Elsevier Science Inc.
M
econium periorchitis is an uncommon cause of a scrotal mass. Meconium periorchitis results from the perforation of the fetal intestine, with meconium traversing a patent processus vaginalis and thus gaining access to the scrotum and causing a local granulomatous reaction. Although meconium periorchitis is a benign process, its clinical presentation often suggests a differential diagnosis that includes testicular tumor. Despite the advancement in radiologic diagnostic techniques, surgical exploration is frequently necessary to provide the definitive diagnosis. We report a case of meconium periorchitis in an infant with multiple scrotal masses. We discuss the management and outcome of the case. CASE REPORT A healthy 16-month-old male infant was evaluated in the pediatric urology clinic for right scrotal masses found by the child’s mother several months before presentation. The infant had no associated urinary symptoms, urinary tract infections, testicular pain, or scrotal swelling. He had been born at term after an uncomplicated pregnancy and delivery. His past medical and surgical history was unremarkable. His physical examination revealed an active male infant without dysmorphic facial features. His abdomen was soft without palpable masses. His phallus was circumcised and of normal
From the Division of Pediatric Urology, Schneider Children’s Hospital, Long Island Jewish Medical Center, New Hyde Park, New York Address for correspondence: Lane S. Palmer, M.D., Pediatric Urology Associates, 833 Northern Boulevard, Great Neck, NY 11021 Submitted: August 29, 2001, accepted: October 16, 2001 © 2002, ELSEVIER SCIENCE INC. ALL RIGHTS RESERVED
size. The meatal opening and location were normal. Visual inspection of both hemiscrotums was unremarkable. The left testis measured about 2 to 3 cm3 in size, with normal consistency. The right testis was about 2 cm3 with multiple, nontender, hard, and irregular nodules located adjacent to the testis. A scrotal ultrasound scan obtained on the day of examination showed clusters of calcification in the scrotum. The separation between the testis and the calcified masses could not be appreciated (Fig. 1). Both testes had a normal homogeneous appearance without any hypoechoic defects or microlithiasis. Scrotal magnetic resonance imaging (MRI) was obtained to help delineate the testis from the calcified masses. The study demonstrated an extratesticular mass with mixed signal intensity involving the body and tail of the epididymis (Fig. 2). The plain film of the abdomen showed no intraabdominal calcifications. At the subsequent surgical exploration through an inguinal incision, a number of yellow-white fibrous nodules were excised from the paratesticular region. No hernia sac was identified intraoperatively. Some of the nodules were arranged in a cluster and adhered to the inner scrotal sac and near the epididymis. The testis and epididymis were normal. Intraoperative frozen specimen analysis suggested meconium calcification. The pathologic analysis of the permanent specimen showed fibrous nodule with mucinous degeneration containing keratinized epithelium and foci of calcification consistent with meconium periorchitis. The results of the preoperative serum alpha-fetoprotein and beta-human chorionic gonadotropin tests were normal. 0090-4295/02/$22.00 PII S0090-4295(01)01545-X 296vii
FIGURE 1. Longitudinal sonographic view demonstrating an echogenic mass at the medial aspect of the right testis. Calcification is evident within the mass with a characteristic acoustic shadow. The demarcation between the mass and the testis is unclear.
COMMENT Meconium periorchitis is a rare clinical entity with a reported incidence of 1 per 35,000 live births.1 It results from intrauterine fetal intestinal perforation with spillage of meconium into the peritoneal cavity. Residual meconium within the process vaginalis can follow the testicular descent and become trapped in the scrotum. The fluid meconium in the scrotum may present as hydrocele at birth and in time cause an intense local granulomatous-like inflammation reaction and dystrophic calcification formation.2 As in the present case, the purported mechanism leaves no gastrointestinal sequelae. The clinical presentation associated with meconium periorchitis was first described by Olnick and Hatcher3 in 1953. The calcifications often mimic a painless, tumor-like scrotal mass on clinical examination. Although most children with meconium periorchitis remain asymptomatic, an acute scrotum caused by a meconium-filled hydrocele sac has been reported.4 Historically, the recommended treatment for meconium periorchitis has been surgical exploration with biopsy of the mass and orchiectomy.3 Currently, a better understanding of the pathophysiology and benignity of this entity makes conservative management the rule once the diagnosis is secured. The diagnosis of meconium periorchitis often can be made through high-resolution, real-time ultrasonography. The intrascrotal calcified stippling on ultrasound scanning with intra-abdominal calcification found on plain film is virtually diagnostic of meconium periorchitis.2 However, the specific 296viii
FIGURE 2. T2-weighted MRI showing the (A) transverse view and (B) coronal view of the right testis with a mixed signal intensity extratesticular mass. The demarcation between the mass and the testis is now evident.
diagnosis may sometimes be difficult, and the clinician must rule out the possibility of malignancy. In the present case, no calcifications were found on the plain film and the sonogram demonstrated large calcified masses. Surgical exploration was undertaken for diagnostic and, if necessary, therapeutic reasons. Had the diagnosis been secured before surgery, none would have been necessary, as these calcifications do not appear to have any long-term implications and can resolve spontaneously without intervention.5 UROLOGY 59 (2), 2002
The differential diagnosis of a scrotal mass with calcification in prepubertal children includes testicular teratoma, gonadoblastoma, calcified Sertoli cell tumor, metastatic neuroblastoma, and torsion with hemorrhagic infarction. Other common paratesticular tumors such as adenomatoid tumor and rhabdomyosarcoma are generally without calcification. Scrotal ultrasonography has traditionally been the diagnostic imaging study of choice in the evaluation of infant scrotal masses, particularly in differentiating intratesticular from extratesticular masses. However, ultrasonography has its diagnostic limitations. This is especially true in the evaluation of infiltrating malignant tumors.6 When the ultrasound diagnosis is inconclusive, other radiologic modalities such as MRI have been used to augment the ultrasound findings. Cramer and colleagues7 studied 200 patients with testicular abnormalities using high-resolution MRI and found that all the MRI findings were confirmed at surgical exploration.7 The investigators advocated using MRI as the alternative diagnostic tool, especially when the clinical examination and ultrasound results were inconclusive. In our patient, the MRI findings were consistent with an extratesticular mass; however, the benignity of the mass was uncertain. An inguinal exploration was consequently performed.
UROLOGY 59 (2), 2002
CONCLUSIONS Meconium periorchitis is a rare and benign cause of a scrotal mass in infants. The clinical diagnosis of meconium periorchitis can be made on the basis of scrotal ultrasound and abdominal plain film findings with the characteristic stippling calcification. Once the diagnosis is made, meconium periorchitis can be managed conservatively. Surgical exploration should be reserved for cases with vague ultrasound and clinical findings to rule out the possibility of malignancy. REFERENCES 1. Payne RM, and Nielsen AM: Meconium peritonitis. Am Surg 28: 224 –231, 1962. 2. Fair K, and Cho MH: Pathological case of the month. Arch Pediatr Adolesc Med 151: 853– 854, 1997. 3. Olnick HM, and Hatcher MB: Meconium periorchitis. JAMA 152: 582–584, 1953. 4. Stokes S, and Flom S: Meconium filled hydrocele sacs as a cause of acute scrotum in a newborn. J Urol 158: 1960 – 1961, 1997. 5. Dehner LP, Scott D, and Stocker JT: Meconium periorchitis: a clinicopathologic study of four cases with a review of the literature. Hum Pathol 17: 807– 812, 1986. 6. Grantham JG, Charboneau JW, James EM, et al: Testicular neoplasm: 29 tumors studied by high-resolution US. Radiology 157: 775–780, 1985. 7. Cramer BM, Schlegel EA, and Thueroff JW: MR imaging in the differential diagnosis of scrotal and testicular disease. Radiographics 11: 9 –21, 1991.
296ix
MECONIUM PERIORCHITIS PRESENTING AS SCROTAL MASSES BARRY CHANG
AND
LANE S. PALMER
ABSTRACT Meconium periorchitis results from calcified meconium trapped in the scrotum and often mimics a testicular malignancy in an infant. Inguinal exploration is warranted if definitive diagnosis cannot be obtained from radiologic evaluations. Magnetic resonance imaging may be helpful in cases in which the scrotal ultrasound findings are inconclusive. UROLOGY 59: 296vii–296ix, 2002. © 2002, Elsevier Science Inc.
M
econium periorchitis is an uncommon cause of a scrotal mass. Meconium periorchitis results from the perforation of the fetal intestine, with meconium traversing a patent processus vaginalis and thus gaining access to the scrotum and causing a local granulomatous reaction. Although meconium periorchitis is a benign process, its clinical presentation often suggests a differential diagnosis that includes testicular tumor. Despite the advancement in radiologic diagnostic techniques, surgical exploration is frequently necessary to provide the definitive diagnosis. We report a case of meconium periorchitis in an infant with multiple scrotal masses. We discuss the management and outcome of the case. CASE REPORT A healthy 16-month-old male infant was evaluated in the pediatric urology clinic for right scrotal masses found by the child’s mother several months before presentation. The infant had no associated urinary symptoms, urinary tract infections, testicular pain, or scrotal swelling. He had been born at term after an uncomplicated pregnancy and delivery. His past medical and surgical history was unremarkable. His physical examination revealed an active male infant without dysmorphic facial features. His abdomen was soft without palpable masses. His phallus was circumcised and of normal
From the Division of Pediatric Urology, Schneider Children’s Hospital, Long Island Jewish Medical Center, New Hyde Park, New York Address for correspondence: Lane S. Palmer, M.D., Pediatric Urology Associates, 833 Northern Boulevard, Great Neck, NY 11021 Submitted: August 29, 2001, accepted: October 16, 2001 © 2002, ELSEVIER SCIENCE INC. ALL RIGHTS RESERVED
size. The meatal opening and location were normal. Visual inspection of both hemiscrotums was unremarkable. The left testis measured about 2 to 3 cm3 in size, with normal consistency. The right testis was about 2 cm3 with multiple, nontender, hard, and irregular nodules located adjacent to the testis. A scrotal ultrasound scan obtained on the day of examination showed clusters of calcification in the scrotum. The separation between the testis and the calcified masses could not be appreciated (Fig. 1). Both testes had a normal homogeneous appearance without any hypoechoic defects or microlithiasis. Scrotal magnetic resonance imaging (MRI) was obtained to help delineate the testis from the calcified masses. The study demonstrated an extratesticular mass with mixed signal intensity involving the body and tail of the epididymis (Fig. 2). The plain film of the abdomen showed no intraabdominal calcifications. At the subsequent surgical exploration through an inguinal incision, a number of yellow-white fibrous nodules were excised from the paratesticular region. No hernia sac was identified intraoperatively. Some of the nodules were arranged in a cluster and adhered to the inner scrotal sac and near the epididymis. The testis and epididymis were normal. Intraoperative frozen specimen analysis suggested meconium calcification. The pathologic analysis of the permanent specimen showed fibrous nodule with mucinous degeneration containing keratinized epithelium and foci of calcification consistent with meconium periorchitis. The results of the preoperative serum alpha-fetoprotein and beta-human chorionic gonadotropin tests were normal. 0090-4295/02/$22.00 PII S0090-4295(01)01545-X 296vii
FIGURE 1. Longitudinal sonographic view demonstrating an echogenic mass at the medial aspect of the right testis. Calcification is evident within the mass with a characteristic acoustic shadow. The demarcation between the mass and the testis is unclear.
COMMENT Meconium periorchitis is a rare clinical entity with a reported incidence of 1 per 35,000 live births.1 It results from intrauterine fetal intestinal perforation with spillage of meconium into the peritoneal cavity. Residual meconium within the process vaginalis can follow the testicular descent and become trapped in the scrotum. The fluid meconium in the scrotum may present as hydrocele at birth and in time cause an intense local granulomatous-like inflammation reaction and dystrophic calcification formation.2 As in the present case, the purported mechanism leaves no gastrointestinal sequelae. The clinical presentation associated with meconium periorchitis was first described by Olnick and Hatcher3 in 1953. The calcifications often mimic a painless, tumor-like scrotal mass on clinical examination. Although most children with meconium periorchitis remain asymptomatic, an acute scrotum caused by a meconium-filled hydrocele sac has been reported.4 Historically, the recommended treatment for meconium periorchitis has been surgical exploration with biopsy of the mass and orchiectomy.3 Currently, a better understanding of the pathophysiology and benignity of this entity makes conservative management the rule once the diagnosis is secured. The diagnosis of meconium periorchitis often can be made through high-resolution, real-time ultrasonography. The intrascrotal calcified stippling on ultrasound scanning with intra-abdominal calcification found on plain film is virtually diagnostic of meconium periorchitis.2 However, the specific 296viii
FIGURE 2. T2-weighted MRI showing the (A) transverse view and (B) coronal view of the right testis with a mixed signal intensity extratesticular mass. The demarcation between the mass and the testis is now evident.
diagnosis may sometimes be difficult, and the clinician must rule out the possibility of malignancy. In the present case, no calcifications were found on the plain film and the sonogram demonstrated large calcified masses. Surgical exploration was undertaken for diagnostic and, if necessary, therapeutic reasons. Had the diagnosis been secured before surgery, none would have been necessary, as these calcifications do not appear to have any long-term implications and can resolve spontaneously without intervention.5 UROLOGY 59 (2), 2002
The differential diagnosis of a scrotal mass with calcification in prepubertal children includes testicular teratoma, gonadoblastoma, calcified Sertoli cell tumor, metastatic neuroblastoma, and torsion with hemorrhagic infarction. Other common paratesticular tumors such as adenomatoid tumor and rhabdomyosarcoma are generally without calcification. Scrotal ultrasonography has traditionally been the diagnostic imaging study of choice in the evaluation of infant scrotal masses, particularly in differentiating intratesticular from extratesticular masses. However, ultrasonography has its diagnostic limitations. This is especially true in the evaluation of infiltrating malignant tumors.6 When the ultrasound diagnosis is inconclusive, other radiologic modalities such as MRI have been used to augment the ultrasound findings. Cramer and colleagues7 studied 200 patients with testicular abnormalities using high-resolution MRI and found that all the MRI findings were confirmed at surgical exploration.7 The investigators advocated using MRI as the alternative diagnostic tool, especially when the clinical examination and ultrasound results were inconclusive. In our patient, the MRI findings were consistent with an extratesticular mass; however, the benignity of the mass was uncertain. An inguinal exploration was consequently performed.
UROLOGY 59 (2), 2002
CONCLUSIONS Meconium periorchitis is a rare and benign cause of a scrotal mass in infants. The clinical diagnosis of meconium periorchitis can be made on the basis of scrotal ultrasound and abdominal plain film findings with the characteristic stippling calcification. Once the diagnosis is made, meconium periorchitis can be managed conservatively. Surgical exploration should be reserved for cases with vague ultrasound and clinical findings to rule out the possibility of malignancy. REFERENCES 1. Payne RM, and Nielsen AM: Meconium peritonitis. Am Surg 28: 224 –231, 1962. 2. Fair K, and Cho MH: Pathological case of the month. Arch Pediatr Adolesc Med 151: 853– 854, 1997. 3. Olnick HM, and Hatcher MB: Meconium periorchitis. JAMA 152: 582–584, 1953. 4. Stokes S, and Flom S: Meconium filled hydrocele sacs as a cause of acute scrotum in a newborn. J Urol 158: 1960 – 1961, 1997. 5. Dehner LP, Scott D, and Stocker JT: Meconium periorchitis: a clinicopathologic study of four cases with a review of the literature. Hum Pathol 17: 807– 812, 1986. 6. Grantham JG, Charboneau JW, James EM, et al: Testicular neoplasm: 29 tumors studied by high-resolution US. Radiology 157: 775–780, 1985. 7. Cramer BM, Schlegel EA, and Thueroff JW: MR imaging in the differential diagnosis of scrotal and testicular disease. Radiographics 11: 9 –21, 1991.
296ix