Teratomas are rare tumors that contain different types of tissues such as bone, teeth, muscle and hair. Sacrococcygeal teratomas (SCTs) are tumors that emerge in the sacrococcygeal area and contain tissue from all three germ layers [1]. They are assumed to be developed from “totipotent somatic cells that are derived from the primitive knot (Hensen's nod) [2]. SCT affects about 1 in every 35,000–40,000 live births [1] .Females are more prone to develop the tumor, with a male-to-female ratio of approximately 1:3, but male infants are more commonly affected by malignant degeneration than female infants. SCTs are usually monitored extensively by physical examination, interval monitoring of serum alpha-fetoprotein (AFP) levels and imaging [4]. Ultrasound allows the clinician to make an antenatal diagnosis, typically in the second trimester via routine sonography [2]. SCTs are divided into 4 types based on the external or internal components of the tumor according to the American Academy of Pediatrics Section on Surgery. Type I is primarily external, Type II is external and has a significant intrapelvic component,   Type III is external and has a pelvic mass, and Type IV is completely internal [2]. The most common type seen is Type I (8/10) followed by Type II (2/10) [1]. Histological grading of SCTs (Gonzalez-Crussi) from grade 0-3 is based on the absence/ presence of immature neural elements and their quantities, as benign (grade 0) - 75%, immature (grades 1-3) - 11.8%, and malignant - 13.2% [1].

18 days old female born term with birth weight 3kg delivered via uncomplicated NVD with no history of previous hospitalization presented in our pediarics emergency of chandka medical college children hospital larkana with noticable abdominal distention for 5 days and vomiting for 1 day. Patient’s findings were only confined with generalized distended Abdomen, with  single huge mass palpable anteriolaterally in right side of abdomen non-tender with regular margins and smooth surface, starting  2cm below right costal margin extending upto 2cm above iliac crest, crossing midline upto left MCL overall measuring 12 cm vertically and 14 cm horizontally. Signs of liver failure including jaundice and Ascites were absent, percussion Note was Dull, Bowel sounds were faintly audible. Patient was passing urine and stool, Genital examination was normal DRE was suggestive of presacral mass.

She was investigated for baselines & evaluation of abdominal mass. CBC revealed Hb=14.5 g/dl, Plt count=218200 cells/cumm & TLC=4410cells/mm, basophils=00, S.electrolytes: Na=132 mmol/L, K=4.7, Cl=103, HCO3=24. U/S abdomen showed a large cystic area appearing large cyst measuring (102*75) with evidence of bilateral mild hydronephrosis & Bilateral Hydroureter. CT whole abdomen with contrast was done that showed large well circumscribed fluid attenuation lesion seen (8.4*11.1 AP/TS)in central & right side of abdominal cavity with thick enhancing septations causing displacement of bowel loops on left side and upper side of abdomen not showing calcification or solid component with evidence of Bilateral hydromephrosis  likely due to compression effect. Radiologists remarks were suggestive of cystic neoplastic lesion, differential can be mesenteric cystic lymphAngioma. Further Histopathological confirmation advised for definitive diagnosis.

After the CT scan reporting, patient was referred to Paeds Surgeon, where Elective excision of tumor was done and sent for histopathology. Histopathology report revealed cystic lesion is derivative of germ layers that predominantly include glial tissue with ependymal lining, features suggestive of Cystic Teratoma.

Figure 1:  CT Abdomen with contrast: Features of Cystic Neoplastic lesion in cenral and right side of Abdominal Cavity.

Figure 2: X-ray Abdomen: Generalized hazziness suggestive of mass shadow on Right side of  Abdomen that do not cause visualization of gut shadows on right side, However, some visualization of bowel loops seen  on  left upper side of abdomen, clinical corelation advised.

SCTs are one of the most common congenital tumors in the fetus [5]. SCTs are extragonadal neoplasms that present as a mass in the midline caudal end of the fetus, can be solid, cystic, or mixed in nature [2]. The cause of SCTs is unknown but the literature reports cases of coexistence of maternal-fetal teratomas,but the specific mechanism is unclear. Therefore, genetic possibilities should be considered [5].It is commonly attached to the coccyx [2]. In the majority of instances, they are asymptomatic or cause rectal or bladder blockage because of tumor development. A patient of SCT can be misunderstood with sacral mass like neural tube defect, myelocystocele or a myelomeningocele, but SCTs are more likely to be presacral [4]. Approximately 32% of SCTs are diagnosed postnatally during the initial newborn assessment due to external component that occurs within the first 24 hours following birth [4]. Mature benign SCTs have a survival rate of approximately 98% compared to a 60% survival rate for immature, malignant SCTs [4].

This should be considered as one of the differential diagnosis in patients presented with abdominal mass. We concluded the diagnosis of primary benign sacrococcydeal cystic teratoma type iv in our patient after clinical, radiological and histopathological findings with negative malignant markers.  Multiple treatment modalities are available including radiotherapy and chemotherapy prior to surgery or surgery can be done directly if completely resectable. In our case it was margin free tumor so proceeded for surgery. The prognosis is good if there is early identification and surgical excision.

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