Mesonephric Remnant (Paroophoron) Presenting as a Congenital Lumbar Sinus in a Child

Abstract

Presence of symptomatic mesonephric duct remnants is rare in pediatric age group. These can be present in dormant physiological or symptomatic pathological states. Pathologies can vary from benign cysts to malignant tumors. We here report a rare presentation in a 2-year-old female, of a mesonephric remnant in the form of a sinus above the iliac crest.

INTRODUCTION

Mesonephric duct remnants (MDRs) are vestiges of the Wolffian (or “mesonephric”) ducts which regress during normal female development.[1] They are usually referred to as paroophoron, epoophoron, and Gartner's duct. Epoophoron usually is found between ovary and fallopian tissue. Paroophoron is found in the mesosalpinx below the epoophoron.[1,2] Gartner's ducts are usually present in the vagina and cervix.[1,2,3,4] In the presence of epithelium and secretory potential, these physiological remnants can become pathological.[1] The pathologies described are usually benign and have a low malignant potential.[1] Pathologies described previously are Gartner's duct cysts, mesonephric hyperplasia, paraovarian cysts, mesonephric carcinomas, and female adnexal tumors of Wolffian origin.[1] All these pathological entities related to mesonephric remnants are rarely found in pediatric age groups, except for Gartner's duct cyst.[4] We here describe another rare presentation of mesonephric remnant in the pediatric age group. The child presented with a sinus above iliac crest communicating with a paroophoron. This presentation has never been described in the literature and appears to be first of its kind.

CASE REPORT

A 2-year-old female child presented with a sinus just above the left iliac crest since birth [Figure 1a]. The sinus very rarely extruded secretions. The child had no complaints in relation to the sinus; however, the parents were worry regarding its future implications. There was no history of fall or bone marrow biopsies or tubercular contacts. There were no symptoms related to bowel and bladder dysfunction. A sinogram done from the opening revealed a well-defined tract along the medial border of ilium, with no communication with any of the pelvic structures [Figure 1b]. Ultrasonography of the abdomen was essentially normal with no clear delineation of the tract.

Figure 1.

(a) Sinus above the left iliac crest; (b) well-defined sinus tract on sinogram

Surgery was done with dissection of the sinus after giving and elliptical skin incision. The tract was sturdy and with a lumen. On deeper dissection, it was found communicating with a serosa lined tubular structure in the region of the mesosalpinx, below the ovary. The tract was about 10 cm long and ended in a bulbous structure in the mesosalpinx and was completely excised [Figure 2]. On histopathological examination, it was found that the sinus tract was lined by stratified cuboidal epithelium and had cheesy keratinous material in it. The sinus tract was found to terminate in a cystic structure consistent histologically with paroophoron.

Figure 2.

Intraoperative findings

The child had an uneventful recovery and has been asymptomatic during the follow-up.

DISCUSSION

MDRs are vestiges of the Wolffian (or “mesonephric”) ducts which regress during normal female development.[1] From cranial to caudal, these remnants are termed as epoophoron between fallopian tube and ovary, paroophoron below the ovary in the broad ligament, and Gartner's ducts and cysts along the cervix and vagina.[1,2] These symptomatic MDRs are rare in the pediatric age group.[1,2,3,4] The most commonly described MDRs in pediatric age groups are Gartner's ducts and cysts.[3,4] In adults, these MDRs can present in the form of paraovarian cyst and benign masses. They have low malignant potential, and adenocarcinomas and metastatic tumors have also been described in adult age groups.[1]

Congenital sinus in the lumbar region near iliac crest is quite rare.[5,6,7] Acquired causes have been described in cases of iliac bone osteomyelitis (traumatic or bone marrow aspirations),[5,6] nephrocutaneous fistula in cases of urinary leaks, and renal abscesses in ectopic kidneys.[7] A congenital sinus above iliac crest has never been reported along with MDRs.

Our patient had no symptoms related to the sinus. The sinogram showed a well-defined sinus tract; however, no communications with internal hollow visceral structures could be identified. The paroophoron cyst excised was benign; however, if left in situ, it posed a low but potential risk of turning malignant.[1]

CONCLUSION

The presence of symptomatic MDRs is rare in the pediatric age group. The presentation of same in the form of a congenital iliac crest sinus can also provide future insights to the complex embryological aspects of the human sexual development.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.