An unusual presentation of pacifier thumb duplication with VACTERL association: Case report and review of literature

Abstract

Introduction and importance

Polydactyly of the hand is a common anomaly among pediatrics, which can present in conjugation with other syndromes or on its own. Various types can be seen, ranging from the involvement of skin only to a completely formed digit. We report the first case of pacifier type thumb duplication presenting with VACTERL association. Herein, we also summarize the existing literature of the distinctive features and management of pacifier polydactyly.

Case presentation

A premature male infant with intrauterine growth restriction due to maternal type II diabetes was referred for a soft tissue attachment to the left hand. The infant showed VACTERL association signs, including a single kidney, small atrial septal defect, and ventricular septal defect. Examination revealed preaxial polydactyly with a cystic swelling connected to the palm.

Clinical discussion

Preaxial polydactyly is the second most common congenital hand anomaly, and its pathology is thought to involve the disruption of apoptosis during embryonic development. Pacifier-type polydactyly is a unique variation characterized by severe edema of the soft tissue digit, believed to be caused by physical damage in utero. The case presented did not require surgical intervention as the duplicated thumb underwent spontaneous autoamputation as opposed to other cases in the literature.

Conclusion

This is the first reported case of pacifier-type thumb duplication in a patient with VACTERL association. The presentation of this condition adds to the existing body of literature on VACTERL association. Surgical removal is the treatment of choice for pacifier polydactyly, but spontaneous resolution can occur.

Highlights

• •The first reported case of pacifier-type thumb duplication with VACTERL association in a male newborn.
• •Our case did not require surgical intervention as the thumb went spontaneous autoamputation.
• •Thumb duplication or preaxial polydactyly has been associated with various syndromes, such as VACTERL syndrome.

1. Introduction

Hand polydactyly is a congenital anomaly characterized by an additional digit as a result of a duplication error during development. It is among the most common congenital hand malformations affecting the ulnar hand (postaxial), the radial hand (preaxial) with thumb duplication, or the central hand (involving the three central rays). The incidence of polydactyly, also known as hyperdactyly, ranges from 0.37 to 1.2 per 1000 live births, varying by race. It can manifest as non-syndromic polydactyly or as syndromic polydactyly [1].

Cases of polydactyly can range from a little skin bulge to a completely formed digit. Generally, it is smaller and less well-defined than the other digits. The additional digit may be skin only, without any bony elements that attach to the hand or foot by a small tissue stalk [2]. To our knowledge, this is the first case of pacifier-type thumb duplication presenting with VACTERL association.

2. Case presentation

A premature male infant was referred from the labor and delivery unit due to a soft tissue attachment to the left hand. The infant was delivered by Cesarean section at 34 weeks of gestation due to intrauterine growth restriction secondary to maternal type II diabetes. The infant required admission to the neonatal intensive care unit due to the small for gestational age and was also noted to have a single kidney, small atrial septal defect, and ventricular septal defect (Fig. 1, Fig. 2, Fig. 3). Considering the constellation of findings, there was a suspicion of VACTERL association, which encompasses vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula, renal anomalies, and limb abnormalities.

Fig. 1.

Renal ultrasound showing a single kidney.

Fig. 2.

Echocardiography showing a small atrial septal defect II with left to right shunt.

Fig. 3.

Echocardiography showing a small restrictive mid-muscular ventricular septal defect with Left to right shunt.

The family history was unremarkable for polydactyly or other congenital malformations. There was no prenatal history of maternal infection, hospital admissions, or surgeries. Maternal medication history included insulin for DM management and folic acid supplementation.

On examination of the left hand, the patient had fully formed five fingers. There was a cystic swelling over the radial aspect of the palm connected with a small stalk (Fig. 4). X-ray revealed a preaxial polydactyly with a soft tissue structure adjacent to and nearly separated from the left thumb, along with a rudimentary bony structure at the distal aspect (Fig. 5). The remaining bony structures appeared unremarkable.

Fig. 4.

Cystic swelling over the radial aspect of the hand.

Fig. 5.

X-ray showing preaxial polydactyly with soft tissue and rudimentary bony structure adjacent to the left thumb.

On the 11th day after birth, the plastic surgery team was consulted due to ulceration and oozing of the mass started two days prior. Upon assessment, no active discharge or bleeding was noted, and the vascularity of the thumb was normal. After 5 days, the lesion underwent ischemia and subsequent spontaneous autoamputation. Fig. 6 depicts the residual scar at 1-month old.

Fig. 6.

Residual scar at 1 month.

Histology of the cystic lesion revealed an extra digit with ischemic changes. The gross description of the specimen showed a tan-gray to tan-red soft tissue measuring 1.6 × 1.5 × 0.6 cm, with serial sectioning revealing a dark-red hemorrhagic cut surface (Fig. 7). The patient was diagnosed with pacifier-type preaxial polydactyly as well as VACTERL association.

Fig. 7.

Histopathological examination shows a polypoidal fragment of connective tissue and cartilage covered by skin with ischemic changes. Histopathology shows low and high power views of ischemic connective tissue (a, b) and cartilage (c) covered by skin (d).

3. Discussion

Preaxial polydactyly (PPD) is a common congenital hand anomaly following postaxial polydactyly, with an incidence of 1 in every 3000–10,000 live births. Radial polydactyly commonly presents as an isolated anomaly but can also be linked to other hand and foot abnormalities or be part of a syndrome like Werner mesomelic syndrome. It may develop sporadically; however, autosomal dominant inheritance pattern is observed more frequently [3]. Regarding its pathophysiology, the aberrant development of the radial digits is thought to be connected to a disruption in apoptosis during the embryonic stage, particularly between the ectodermal and preaxial mesodermal tissues, which occurs prior to the eighth week of gestation [4,5].

Four types of PPD have been identified by Temtamy and McKusick [6]: PPD-I, which is polydactyly of a biphalangeal thumb; PPD-II, which is polydactyly of a triphalangeal thumb; PPD-III, which is polydactyly of an index finger; and PPD-IV, which is polysyndactyly. The most prevalent type is Type IV or duplicated proximal phalanx, occurring in 43 % of cases, and it might be associated with conditions including tibial deformities, Fanconi's anemia, imperforate anus, Holt-Oram syndrome, Blackfan-Diamond anemia, and cleft palate [3]. Moreover, Wassel further divided PPD-I into six subgroups according to the osseous duplication [3]. Nevertheless, some cases of thumb duplication do not fit into the current classification criteria.

A unique variation occurs in which there is significant edema of the soft tissue “nubbin” that is continually being sucked by the newborn, thereby resulting in a condition known as pacifier polydactyly. The presence of this severe edema is a distinguishing feature and is believed to be caused by physical damage to the uterus, such as the fetus sucking on it. Thus, if the histology does not exhibit edema of this nature, it should not be regarded as pacifier-type polydactyly. Edema is caused by in-utero twisting of the neurovascular bundle in the thin skin stalk. The condition was initially documented as postaxial polydactyly in the 1990s [7]. In recent years, it has been reported a few times to develop radially. While the clinical pictures and interventions were similar, various terms were used to describe the condition, including “large preaxial polydactyly with intraepidermal bulla” and “Pacifier PPD.” This variation in terminology arose because not all cases met the criteria of a substantialy edematous duplication of the thumb connected by a soft tissue stalk [8,9].

Pacifier polydactyly is often mistaken for either pedunculated polydactyly or rudimentary polydactyly. Pedunculated polydactyly refers to small, incomplete digits with osseous elements, whereas rudimentary polydactyly refers to incomplete digits without osseous elements that resembles wart-like tumors. Furthermore, it has been claimed that pacifier polydactyly is the intermediate form among these two forms [7]. Similarly, a mass-like appearance may also be seen with floating thumbs which is thought to have a similar pathophysiology as pacifier radial type polydactyly [10]. Although floating thumb has been frequently linked to VACTERL association, this is the first reported instance of a pacifier-type thumb duplication in conjunction with VACTERL association [11].

As for the management of pacifier polydactyly, ligation is no longer recommended as it may result in amputation neuroma, as reported in one case [9]. Instead, surgical removal is the treatment of choice to avoid such complication. Unlike other reported cases in the literature which required surgical intervention, ours did not require any as the extra digit had undergone spontaneous ischemia and subsequent autoamputation [8,9]. Comprehensive evaluation and follow-up, even where spontaneous resolution occurs, are imperative to ensure optimal care for affected individuals.

In conclusion, preaxial polydactyly (PPD) is a common condition where the thumb or finger is duplicated. It can occur sporadically or be inherited, and disruptions in embryonic development are believed to be involved. There are four types of PPD, with Type IV being the most common. Pacifier polydactyly is a unique variation with significant swelling, often mistaken for other types. Surgical removal is the preferred treatment, although spontaneous resolution can happen.

4. Conclusion

This, to our best knowledge, is the first case of pacifier-type thumb duplication in a VACTERL-association-affected individual. The presentation of this condition adds to the existing body of literature on VACTERL association and expands our understanding of the diverse manifestation of this association. Our work has been reported in line with the SCARE criteria [12].

Ethical approval

No ethical approval required for case reports.

Funding

The authors do not have any conflict of funding to declare.

Author contribution

Nouf Z. AlBattal: concept, design, definition of intellectual content, literature search, manuscript preparation, manuscript editing and manuscript review.

Ali M Alkhathami: concept, design, definition of intellectual content, manuscript editing and manuscript review.

Bushra Alhazmi: concept, design, definition of intellectual content, manuscript editing and manuscript review.

Ahmed T Alturki: concept, design, definition of intellectual content, manuscript editing and manuscript review.

Rahaf Mohammed BinManie: definition of intellectual content, manuscript editing and manuscript review.

Guarantor

Nouf Z. AlBattal.

Conflict of interest statement

The authors do not have any conflict of interest.