Sacrococcygeal Teratoma

A germ cell tumor arising from the presacral area.

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1:40,000 births. The female to male ratio is 4:1, but malignant changes are more frequently seen in males.^1,2 

Sacrococcygeal teratoma is believed to arise from the primitive knot or Hensen's node, an aggregation of totipotential cells that act as the primary organisers of embryonic development. Initially located in the lower dorsal area of the embryo, Hensen's node migrates caudally inside the tail of the embryo during the first week post-conception, eventually resting anterior to the coccyx. This theory provides an explanation for the more frequent occurrence of teratomas in the sacral area rather than in other part of the body.³  

An alternative theory of “twinning accident” with incomplete separation during embryogenesis has also been proposed. Although the majority of sacrococcygeal teratomas occur sporadically, some cases, typically associated with anorectal stenosis and sacrococcygeal defects (Currarino syndrome) are transmitted with autosomal dominant inheritance.^{4, 5, 6}

The American Academy of Pediatrics¹ distinguishes four types of sacrococcygeal teratomas:

• Type 1: Predominantly external, with minimal presacral component.
• Type 2: Predominantly external, with significant intrapelvic component.
• Type 3: Predominantly internal, with abdominal extension.
• Type 4: Entirely internal with no external component.

80 % of the cases are Type 1 and 2. Only 10% of the SCT are of Type 4.  In 15% of cases the tumor is entirely cystic, the remaining 85% of cases being either solid or mixed.

Histologically, sacrococcygeal teratomas are categorized into three main groups. Mature (or benign) teratomas consist of tissues similar to normal, well developed structures (skin appendage, bone, glia, bowel, pancreas). Fully formed organs may be present, such as bowel loops, fingers and teeth. Choroid plexus is frequently found and is responsible for the production of the fluid that forms cysts within the tumor. Immature teratomas contain a different proportion of embryonal tissues, usually of neuroepithelial or renal origin. Malignant teratomas are yolk sac or endodermal sinus tumors and produce alpha-fetoprotein. Mature and immature teratomas are frequently cystic, malignant forms are predominantly solid. Solid tumors usually have an important vascular component and may be complicated by high output cardiac failure, hydrops and spontaneous hemorrhage. Mature, immature and malignant forms account in different series for 55-75%, 11-28% and 7-13% respectively.⁷ 

Postnatal studies report an incidence ranging between 5 % to 25% and involving various systems with no specific pattern. Prenatal series, in contrast, only rarely reported associated findings, with the exception of hydrops and polyhydramnios.

Kivilevich⁸  reviewed a total of 134 cases of sacrococcygeal teratoma.^{9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23} The diagnosis is simple for type I, II and III: a mass is seen arising from the presacral area and protruding through the perineum. Most sacrococcygeal teratomas identified in utero have a complex appearance with solid and cystic components. Rarely the tumor displays either a completely solid or cystic appearance. Large, solid teratomas have an important vascular component which is easily demonstrated using colour Doppler. Identification of type IV lesions is difficult since the mass is entirely intra-abdominal and a specific diagnosis may be impossible. Polyhydramnios and hydrops may develop as a consequence of hyper vascularity and/or anemia following intratumoral hemorrhage, leading to high output cardiac failure.

The prognosis is related to three factors: the development of fetal hydrops, histology of the lesion and size of the tumor. Hydrops occurs typically when tumors have significant solid and vascular components and is most frequently associated with perinatal death. In a large series, 3 out of 4 survivors had undergone fetal intervention by open uterus surgery. Malignant tumors are almost invariably and rapidly fatal. In this regard, the classification of the macroscopic type is relevant. In fact, type I is rarely if ever malignant, while with type II, III and IV the probability of metastases is 6, 20 and 76% respectively.¹  The size of the tumor does not seem to predict malignancies, but is important, because very large lesions are associated with a greater surgical risk. In a review of 134 cases diagnosed in utero,⁸ the perinatal mortality rate was 35 %, excluding 17 cases of elective abortion. The available evidence suggests that a good outcome is expected from small lesions, predominantly external, cystic and avascular. Conversely, the outcome is poor when a solid vascular lesion with significant internal component is seen.

Termination of pregnancy can be offered to the parents. In continuing pregnancies, serial sonograms and Doppler ultrasonography to follow-up the growth and the vascularization of the tumor are indicated. 
Large sacrococcygeal tumors may cause severe soft tissue dystocia. With a large tumor, elective cesarean section is mandatory. With predominantly cystic lesions, aspiration may reduce the volume of the tumor, making vaginal delivery possible
 

1. Altman, R.P., Randolph, J.G., Lilley, J.R. Sacroccocygeal teratoma: American Academy of Pediatrics Surgical Section Survey. J Pediatr Surg 1974;9:389-398..
2.   Donnellan WA, Swenson O: Benign and malignant sacroccygeal teratomas. Surgery 64:834, 1968
3.   Gross RE, Clatworthy HW Jr, Meeker IA: Sacroccygeal teratomas in infants and children. A report of 40 cases. Surg Gynecol Obstet  92:341, 1951.
4.   Sonnino RE, Chou S, Guttman FM: . Hereditery Sacrococcygeal Teratoma. J. Pediatr. Surg. 24 : 1074- 1075, 1989
5.   Hunt P. T et. al. 1977 . radiography of hereditary presacral teratoma. Radiology,122 : 187- 191
6.   Kochling J, Pistor G, Marzhauser Brands S, Nasir R, Lanksch WR: The Currarino Syndrome - Hereditary syndrome of anorectal, sacral and presacral anomalies . case report and review of the literature. Eur. J. Pediatr. Surg. 1996, 6 :114
7.   Valdiserri R.O,  Yunis E.J Sacrococcygeal teratoma : a review of 68 cases. Cancer, 1981, 48 :217-221
8.   Kivilevich Z: Sacroccygeal teratoma. WWW.thefetus.net, 2000.
9.   Gross SJ, Benzie RJ, Sermer M, Skidmore MB, Wilson SR: Sacrococcygeal teratoma :Prenatal diagnosis and management. Am. J. Obstet. Gynecol. 1987 ; 156 :393-396.
10.   Hogge WA, Thiagarajah S, Barber VG, Rodgers BM, Newman BM: Cystic sacrococcygeal teratoma : ultrasound diagnosis and perinatal management. J. Ultrasound Med. 1987 ; 6 : 707 -710.
11.   Sheth S, Nussbaum AR, Sanders RC, Hamper UM, Davidson AJ: . Prenatal diagnosis of sacrococcygeal teratoma: Sonographic -Pathologic correlation. Radiology 1988 ; 169 :131 -136
12.   Teal LN, Angtuaco TL, Jimenez JF, Quirk JG Jr:  Fetal Teratomas : Antenatal diagnosis and clinical management. J. Clin. Ultrasound 1988 ; 16 :329 - 336.
13.    Bond S.T et.al Death due to high output cardiac failure in fetal sacrococcygeal teratoma. J. Pediatr. Surg. 1990 ;25 : 1287 -1291.
14.   Evans MJ, Danielian PJ, Gray ES:. Sacrococcygeal teratoma : a case of mistaken identity. Pediatr. Radiol. 1994 : 24 : 52-53.
15.   Shipp TD, Shamberger RC, Benacerraf BR: Prenatal diagnosis of a grade 4 sacrococcygeal teratoma. J. Ultrasound Med. 1996 ; 15 :175 - 177.
16.   Winderl L.M, Silverman R.K . Prenatal identification of completely Cystic internal sacrococcygeal teratoma ( type 4 ) . Ultrasound Obstet. Gyneccol. 1997; 9 : 425 -428.
17.   Sherer DM, Fromberg RA, Rindfusz DW, Harris BH, Sanz LE: Color Doppleraided prenatal diagnosis of a type 1 cystic sacrococcygeal teratoma simulating a meningomyelocele . Am. J. Perinatol.1997 ; 14 : 13 - 15.
18.   Kirkinen P, Heinonen S, Vanamo K, Ryynanen M: Maternal serum alpha- fetoprotein and epithelial tumor marker concetration are not increased by fetal sacrococcygeal teratoma. Prenatal Diagnosis ,1997 ; 17 :47 -50.
19.   Montgomery ML, Lillehei C, Acker D, Benacerraf BR: . Intra- abdominal sacrococcygeal mature teratoma or fetus in fetus in a third - trimester fetus. Ultrasound Obstet Gynecol 1998 ; 11 : 219 -221.
20.   Burgess I, Hines B, Stevenson P: Cystic Type 4 sacrococcygeal teratoma detected at 18 week prenatal diagnosis .1998 ; Ultrasound Obstet. Gynecol. ; 11; 305.
21.   Holterman AX, Filiatrault D, Lallier M, Youssef S: The natural hystory of Sacrococcygeal teratoma diagnosed through routine obstetric sonogram: a single institute experience. 1998 , J. Pediatr. Surg. ; 33 : 899 - 903.
22.   Chisholm CA, Heider AL, Kuller JA, von Allmen D, McMahon MJ, Chescheir NC: Prenatal diagnosis and perinatal management of fetal sacrococcygeal teratoma.  1999 Am. J. Perinatol. ; 16 : 89 -92.
23.   Westerburg B, Feldstein VA, Sandberg PL, Lopoo JB, Harrison MR, Albanese CT: Sonographic prognostic factors in fetuses with sacrococcygeal teratoma . 2000 J. Pediatr. Surg. ; 35 : 322 - 325.

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