Human Tail: A Benign Condition Hidden Out of Social Stigma and Shame in Young Adult - A Case Report and Review

A case of dumbbell-shaped accessory scrotum with concomitant lipoma

BACKGROUND

Accessory scrotum is a congenital scrotal anomaly that is usually located anterior to the anus and frequently presents with a lipoma in a bead-like shape. Herein, we present an unusual case of an accessory scrotum with a lipoma connected by a narrow stalk and located posterior to the anus.

CASE PRESENTATION

A 1-month-old boy was referred to our hospital for a perineal mass present at birth. He was born at 37 weeks and 2 days, with a birth weight of 2962 g. No abnormalities occurred during the perinatal period, and the birth was uneventful. The mass had an unusual shape, comprising two masses connected by a narrow stalk. The base of the mass was posterior to the anus and was connected to the rectal mucosa. The proximal mass was elastic and soft without skinfolds, whereas the distal mass was elastic and soft with a scrotum-like skinfolds. Magnetic resonance imaging showed no spina bifida. High-intensity adipose tissues in both masses and low-intensity vessels or fibrous stroma in cord-like structures between the two masses were found on T2-weighted images. At 3 months of age, the patient underwent resection in the prone jackknife position. No tumorous lesions were connected to the mass on the rectal and coccyx sides, and the mass was completely removed, preserving the anal sphincter. Histologically, the distal mass had characteristics of a scrotum, whereas the proximal mass was exclusively a lipoma. The connecting stalk had normal skin structures and a blood vessel with parallel-running nerve bundles. The postoperative course was uneventful, and the patient was discharged on postoperative day 6.

CONCLUSIONS

This case of accessory scrotum was unusual in its location and the presence of a stalk connecting the accessory scrotum and lipoma. The mechanism underlying accessory scrotum development remains unclear, and our report may impact the discourse regarding the embryological development of the accessory scrotum.

Atavistic and vestigial anatomical structures in the head, neck, and spine: an overview

Organisms may retain nonfunctional anatomical features as a consequence of evolutionary natural selection. Resultant atavistic and vestigial anatomical structures have long been a source of perplexity. Atavism is when an ancestral trait reappears after loss through an evolutionary change in previous generations, whereas vestigial structures are remnants that are largely or entirely functionless relative to their original roles. While physicians are cognizant of their existence, atavistic and vestigial structures are rarely emphasized in anatomical curricula and can, therefore, be puzzling when discovered incidentally. In addition, the literature is replete with examples of the terms atavistic and vestigial being used interchangeably without careful distinction between them. We provide an overview of important atavistic and vestigial structures in the head, neck, and spine that can serve as a reference for anatomists and clinical neuroscientists. We review the literature on atavistic and vestigial anatomical structures of the head, neck, and spine that may be encountered in clinical practice. We define atavistic and vestigial structures and employ these definitions consistently when classifying anatomical structures. Pertinent anatomical structures are numerous and include human tails, plica semilunaris, the vomeronasal organ, levator claviculae, and external ear muscles, to name a few. Atavistic and vestigial structures are found throughout the head, neck, and spine. Some, such as human tails and branchial cysts may be clinically symptomatic. Literature reports indicate that their prevalence varies across populations. Knowledge of atavistic and vestigial anatomical structures can inform diagnoses, prevent misrecognition of variation for pathology, and guide clinical interventions.

A human tail arising from the anal mucocutaneous junction: A case report

Introduction

Human tails are rare congenital malformations that describe protrusions commonly located around the midline of the lumbosacral region covered by skin, representing an embryonic remnant. Human tails are broadly classified into true and pseudo-tails. The real ones represent the persistence of a remnant of the embryonic tail formed between the fourth and eighth week of gestation.

Presentation

A male infant aged 42 days presented to our institution with a tail-like structure that originated from the anal mucocutaneos junction. The parents did not bring the baby at birth because of the social stigma and ignorance. On examination, there was a tail-like structure that is about 22 cm in length and 1.5 cm in diameter originated from the mucocutaneous junction at the anus at the left side. There was no bony element on palpation. The lower vertebral column examination showed no abnormalities, and this was confirmed with an x-ray. The patient was operated on with simple excision of the tail and primary closure of the wound at the base. He was discharged on the same day well and good. The tail was taken for microscopic histopathology.

Discussion

There are few reported cases describing human tails. However, none of them was originating from the anal mucocutaneous junction.

Conclusion

We report the first case of a human tail arising from the anal mucocutaneous junction worldwide. Due to its very superficial origin, it was not associated with any other anomalies.

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Human tails are rare congenital protrusions located commonly around the midline of the lumbosacral region

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It is the first reported case worldwide of a human tail arising from the anal mucocutaneous junction.

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We performed a simple excision of the tail and a primary closure of the defect and the tail was sent for histopathological examination