BODY STALK ANOMALY: CLINICAL AND HISTOPATHOLOGIC FINDINGS OF THIS RARE ANOMALY IN A NIGERIAN NEWBORN

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K.I Egbuchulem¹, O.O Ogundoyin^1,2, D.I Olulana^1,2, A.A Salami^3,4, O.S Adamo³, O.T Ojediran¹

1. Division of Paediatric Surgery, Department of Surgery, University College Hospital, Ibadan.
2. Department of Surgery, University of Ibadan, Ibadan.
3. Department of Pathology, University College Hospital, Ibadan.
4. Department of Pathology, University College Hospital, Ibadan.

Abstract

Introduction: Body stalk anomaly (BSA) is a rare and severe congenital malformation in which the exact pathophysiology is still unknown. The possible causes of body stalk anomaly include early amnion rupture with direct mechanical pressure and amniotic bands, vascular disruption of the early embryo, or an abnormality in the germinal disk.

Case presentation: We report a case of sonologically delayed diagnosis of BSA which was confirmed post-delivery following histopathological examination and we reviewed relevant literature regarding this phenomenon. Sonographic features of the foetus included a wide anterior abdominal wall defect (omphalocele) with protrusion of the liver into the amniotic cavity. The umbilical arteries show normal calibre, flow, velocimetry, and spectral waveform.

Conclusion: Body stalk anomaly is accepted as a fatal anomaly, so it is important to differentiate it from other anterior abdominal wall defects prenatally and this could guide the management options.

Keywords: Body stalk anomaly, Anterior abdominal wall defect, Prenatal ultrasound scan, Nigerian

Introduction

Body Stalk Anomaly (BSA), is a rare foetal congenital anomaly with an almost universally fatal outcome postnatally.1 The incidence at birth is about 0.2-0.3/ 100,000 live births because most of the affected foetuses undergo intrauterine deaths.^{2, 3}.

In a recent multicenter study by Daskalakis et al.⁴ in which 106,727 foetuses between 10 and 14 weeks of gestation were analysed, an incidence of 1/7,500pregnancies were found to be affected. This discrepancy in the incidence rates suggests that this type of malformation might be responsible for a significant number of spontaneous abortions during the first trimester of pregnancy, and thus the real incidence for this anomaly might be underestimated. Of all the types of anterior abdominal wall defects, body stalk anomaly is the most severe and invariably lethal abdominal wall defect. It is a severe defect in which the abdominal wall does not develop and thus the peritoneal cavity is open to the extraembryonic coelom and the fetus is attached to the placenta.⁴ The presence of the liver and intestine in the extraembryonic coelom differentiates body stalk anomalies from other subtypes. Body stalk anomaly is generally not associated with chromosomal anomalies⁴, however it might occur in conjunction with neural tube defects, genitourinary malformations, abnormalities of the chest wall, intestinal atresia, and craniofacial defects, among others.^5,6 The variety of phenotypes in the reported cases worldwide has led to the creation of a confusing array of terms for this condition including the amniotic band syndrome, short umbilical cord syndrome, and limb-body wall complex.7,8