Unusual presentation of sacrococcygeal teratomas and associated malformations in children: clinical experience and review of the literature.

BACKGROUND

Sacrococcygeal teratomas are the most common and best known extragonadal teratomas in neonates and infants, but they sometimes present unique, distinctive features unlike those commonly described, that can be considered exceptional and noteworthy.

MATERIAL AND METHODS

The Authors reviewed the most significant (Table I, II) clinical, laboratory, radiological and pathologic findings, surgical procedure, and early and long-term results in 5 children, 2 males and 3 females, suffering from sacrococcygeal teratomas. Four of 5 patients were observed and managed in the neonatal age. A prenatal diagnosis had already been made in 2 of them between the 2nd and 3rd trimester of pregnancy. Two patients were also suffering from the Currarino syndrome associated with Hirschsprung's disease and other, multiple malformations and a cloacal anomaly with anal imperforation, respectively. This last developmental anomaly had been prenatally suspected at US scanning, which had demonstrated a severe sacral anomaly and a large abdominal mass with perineal extension and dilated bowel loops. All the infants were born by scheduled caesarean section in a tertiary care hospital and were then referred to the N.I.C.Us. because of a mostly acute clinical presentation, except for case N°4, who was referred at the age of 3.3 years. Laboratory and radiologic investigations confirmed the clinical diagnosis of teratoma on the basis of elevated AFP values and imaging findings. All patients underwent emergency surgical management, in accordance with recommended practice, consisting of complete exeresis of the tumor, including coccygectomy, in 3 of the 5 children.

RESULTS

Of the 5 patients, the female newborn affected by the Currarino syndrome, associated with persistence of the common cloacal canal and anal imperforation, died two days after surgery, of cardiovascular and respiratory complications. All the other patients had an uneventful postoperative course. Two years after the first exeresis at birth, relapse was observed in case N° 3, with a malignant component, YST, anticipated by elevated AFP values but negative physical signs and a benign cystic imaging pattern. After adjuvant chemotherapy she underwent a second complete exeresis. So far, 3 years after the second surgery and 5 years after the diagnosis and first treatment, no local recurrence or distant metastases have occurred. The other 3 patients are also all alive, disease-free and with no signs of relapse or distant metastasis, after a follow-up ranging from 2 years to 28 years. None of the 3 cases treated for sacrococcygeal teratoma, operated in 1985, 1984 and 2006, have ever developed functional sequelae such as ano-rectal and/or bladder dysfunction or hypotonia of the lower limbs.

CONCLUSIONS

From this review of our selected cases and in the light of literature reports, we can draw the following conclusions. Some sacrococcygeal teratomas may have unique characteristics distinguishing them from more common cases, especially those included in the Currarino Syndrome, with or without an association with other malformations such as Hirschsprung's Disease and Cloacal anomalies. Being congenital tumors, prenatal diagnosis by US scan is extremely important in order to decide either for an anticipated delivery or to perform, in critical fetuses, prenatal treatment within highly specialized facilities, or to organize proper perinatal care, always in appropriate facilities where it is possible to define the diagnosis and carry out emergency surgery. An emergency procedure is frequently dictated both by complications related to the mass effect, and by the need to define the histology of the whole mass rather than just small biopsy specimens. Some sacrococcygeal teratomas can hide more or less extensive islands of immaturity or signs of malignant transformation that are clinically evident. The prognosis is generally benign, although AIEOP (Associazione Italiana Ematologia Oncologica Pediatrica) 2004 guidelines pointed out that high levels of circulating markers, including AFP, in children affected by mature or immature teratomas would indicate the presence of micro-foci of YST, marking them out as at high risk. The UKCCSG II (Children UK Cancer Study Group) and the SFOP (Société Française d'Oncologie Pédiatrique) indicated AFP values exceeding 10,000 ng / ml as the threshold identifying a group of patients with severe prognosis. The treatment indicated is early, complete exeresis, followed by a careful, extensive microscopic examination associated, if necessary, with adjuvant chemotherapy, that is indicated before surgery only in infiltrating primary malignant teratomas. Sacrococcygeal teratomas are commonly considered as lesions at particular risk, in which the coccyx must always be removed together with the mass and overlying skin, taking particular care of the deep pelvic fascia to prevent functional disorders of the bladder and anal canal, as well as any motor alterations of the lower limbs, usually due to iatrogenic lesions of the subfascial nerve structures. There is a ananimous consensus that to improve the prognosis, close, long-term clinical, laboratory and imaging surveillance is essential at shorter intervals during the first 5 years after the exeresis and annually thereafter. In newborns or infants suffering from congenital malformations associated with teratomas, definitive surgical correction, if indicated, must obviously be postponed to a proper time, especially in patients with multiple malformations or needing adjuvant chemotherapy, unless a complication arises or the repair cannot be delayed.