Pelvic Mass in a Newborn

This submission has open access
Submission ID :
ESPR70
Submission Type
Submission Topic
Abstract: :

History

A 7-day-old female presented to the hospital for evaluation of a right-sided pelvic mass. 

She was born at 39 weeks gestation via emergency cesarean section due to failure to progress; 1 and 5-minute APGAR scores were 9 and 9. The patient had no postnatal complications, including no difficulties feeding, voiding or stooling, and was able to be discharged home on day of life 3.

Mother's prenatal history was significant for early identification as a twin pregnancy, however, a subsequent ultrasound revealed findings consistent with vanishing twin syndrome. The pregnancy was also complicated by gestational hypertension, requiring serial ultrasounds to monitor fetal growth. A repeat ultrasound at 36 week gestation discovered a right-sided complex, cystic pelvic mass measuring 3.7cm x 3.5cm x 3.1cm. At that time, the mass was presumed to be an ovarian cyst and postnatal follow up with Pediatric Surgery including a repeat ultrasound was arranged.  

The repeat ultrasound was performed at 1 week of life and demonstrated a large, complex, vascularized, multiloculated cystic and solid lesion within the pelvis, which had increased in size from prior prenatal scans and measured 7.7cm x 3.5cm x 6.5cm. The ovaries were unable to be visualized. Given the rapid growth of the patient's pelvic mass, she was urgently admitted to the hospital for further evaluation.


Physical Exam

Heart Rate: 137/min       Respiratory rate: 58/min     Temperature: 98.1 F   Blood pressure: 88/49

She was alert, well appearing in no acute distress. Her abdominal examination was significant for right sided abdominal fullness. Abdomen was otherwise soft, and non-tender with normal bowel sounds in four quadrants. Pelvic examination showed normal female genitalia. Her respiratory and cardiovascular examination was unremarkable 


 
 Labs/Images and Procedures

Complete blood count including differential and renal function tests were within normal limits

LDH 388 (178 - 629 U/L)

Uric acid 3.3 (2.0 - 5.5 mg/dL)

Alpha fetoprotein (AFP) tumor marker 13,244.7 (0.9 - 8.8 ng/mL) (elevated, but considered normal in the neonatal period per Pediatric Oncology consultation)

Beta HCG <0.6 (<=50 U)

An MRI was performed on admission and demonstrated a complex structure in the right lower abdomen measuring 7.0cm x 4.0cm x 4.6cm. The structure appeared to be comprised mostly of anechoic fluid with a heterogenous and mostly solid component containing calcified elements, without well-defined anatomic structures (Image 1).

The patient was brought to the operating room for exploratory laparotomy and mass resection on day of life 9. Intra-operatively, the mass was found deep within the retroperitoneum and was noted to be adherent to the bladder wall with involvement of bilateral ureters. There was no involvement of mullerian structures. Ultimately, the mass was separated from the bladder wall without injury, ureteral adhesions were lysed and the mass was resected and sent to Pathology for final diagnosis (Image 2a).

An x-ray of the resected mass revealed the presence of vertebral bodies (Image 2b). Cytogenetic studies were unremarkable. Chromosomal analysis of the mass demonstrated a normal karyotype, 46 XX, without evidence of acquired clonal abnormalities.


Final Diagnosis: Fetus in fetu (FIF)

Discussion

Here, we report a case of a 7-day old female who was diagnosed with a pelvic mass in utero in the setting of a history of vanishing twin syndrome. Postnatally, the mass was noted to have rapid growth, prompting further imaging, which demonstrated a complex structure suggestive of FIF. The decision was made to proceed to the operating room and the mass was successfully excised. Further examination of the mass confirmed the diagnosis. 

Fetus in fetu is a rare congenital anomaly in which a malformed twin becomes incorporated into the body of its host in a monochorionic-diamniotic pregnancy. The pathogenesis of FIF remains unclear as there are many theories debated; however, the most cited theory reports an aberration during ventral folding of the trilaminar embryonic cyst, in which there is unequal division of the totipotent inner cell mass of the developing blastocyst, causing a small cell mass to be included in the host as a vestigial remnant. This inclusion is thought to be due to a persistent anastomosis of the vitelline circulation. When presented with a case of possible FIF, the differential diagnosis should also include benign or malignant ovarian tumors as well as mature teratomas. Key differentiating factors that distinguish FIF from the others includes the presence of an axial skeleton (or remnants thereof) and it is typically non-malignant.


Optional insertion of relevant images :
If the file does not load, click here to open/download the file.
If the file does not load, click here to open/download the file.
Inova Children's Hospital
Inova Fairfax Hospital
Inova Children's Hospital
Inova Fairfax Hospital
University of Virginia
Georgetown University
Inova Fairfax Hospital
Inova Children's Hospital
Inova Children's Hospital

Similar Abstracts by Type

Submission ID
Submission Title
Submission Topic
Submission Type
Corresponding Author
ESPR72
Clinical Case
Clinical case
Vanessa Denny
ESPR429
Clinical Case
Clinical case
Vaishali Adlakha
78 hits