Retroperitoneal teratomas are rare, representing only 1% to 11% of primary retroperitoneal neoplasms . They typically present as asymptomatic abdominal mass but can grow to enormous size. There are only 2 children reported hitherto who had presented with acute abdomen. Pontinen et al almost half century ago, had reported a retroperitoneal teratoma in a three year old girl that simulated an acute appendicitis . Nguyen et al had recently described a 9-year-old girl who presented with an acute abdomen because of an abdominal abscess that was treated with surgical drainage and antibiotics . Fifteen years later, she had a recurrence of symptoms and the abscess was ultimately recognized to be an infected retroperitoneal teratoma. Though the diagnosis of infected retroperitoneal teratoma was made at the age of 24 years, this teratoma must have been present since birth and got missed at the earlier presentation in the childhood.
Most of the retroperitoneal tumors in childhood are cystic and benign . Spontaneous rupture of cystic retroperitoneal teratomas is a rare occurrence probably because of the thick encasing capsule. Taking analogy from cystic ovarian teratomas, two clinical presentations could be associated with such intraperitoneal rupture of benign cystic teratomas . The first is acute peritonitis caused by the sudden rupture of tumor contents, which may occur spontaneously or more commonly in association with torsion, trauma, infection, or labour. The second presentation is chronic granulomatous peritonitis resulting from a chronically leaking dermoid, which can be characterized by multiple small white peritoneal implants, dense adhesions, and variable ascitis that simulate carcinomatosis or tuberculous peritonitis. The latter is the more common presentation in case of cystic ovarian teratomas .
CT scan is considered as better radiological investigation than ultrasonography for the diagnosis of RPTs . MRI has been also used recently. At CT, a mature RPT manifests as a complex mass containing a well-circumscribed fluid component, adipose tissue, and calcification . The presence of hypoattenuating fat within the cyst and the presence of calcifications in the cyst wall are considered highly suggestive of cystic RPT . At CT, the presence of fat-fluid levels in the peritoneum has been quoted as a reliable sign of intraperitoneal rupture of abdominal teratoma and subsequent chemical peritonitis . However, the diagnosis of rupture of RPT is usually made at operation.
The operative management of RPTs, especially those with rupture, may be complex and challenging. Despite their benign nature, the lesions can attenuate and surround major vessels, making resection difficult. Preoperative imaging has been known to be offer limited help in demonstrating the position of the major vessels . In particular, the veins may be effaced. Excision of ruptured RPT in our case was also a formidable surgical exercise.
In conclusion, rupture of RPT is an extremely rare phenomenon. It may be difficult to make a preoperative diagnosis and the surgical excision could be a challenging task.