CME article 13

Polyorchidism,a rare congenital anomaly.
Polyorchidism is a rare congenital anomaly having more than two testes either intra or extra-scrotal. Less than hundred reported cases have been found till date. The main objective is to describe embryological, clinical and sonographic features of polyorchidism and review the literature of similar cases.

In this case, a 16 year old boy presented with painless right sided scrotal mass for one year. Clinically, a well defined nodular lesion without any cough impulse was noted in the right hemiscrotum. Sonography was done using 5MHz probe including Doppler.

A well defined nodular lesion having same echogenicity and Doppler signals as normal testis was noted in the right hemiscrotum. An epididymis like structure was also noted along with it. Sonographic features were complementary to supernumerary testis with epididymis.

Though polyorchidism is a rare congenital anomaly but high clinical suspicion and sonographic features can give a confirmatory diagnosis.


Introduction:

Polyorchidism is a rare congenital anomaly. Historically,the first reported occurrence can be traced back to 14th century .1,4 In the year 1880 first histological description of supernumerary testis was given.2,4 The first clinical case was reported in 1895.3,4 Till date less than hundred cases have been reported. The most common type of polyorchidism is triple testes or triorchidism6,24. Left sided intrascrotal supernumerary testis is the commonest variety. Here we have reported an interesting case of right sided intrascrotal supernumerary testis.



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Case report:

A 16 years old boy with the medical history of painless mass lesion in right side of scrotum for one year was referred for sonography. According to the patient it was an accidental detection following a minor trauma. There was no change in size of the mass over the period. Sonographic examination using 5Mhz probe revealed a well defined nodular lesion having similar echogenicity and centripetal vascularity as normal testis in right hemiscrotum.It was placed inferomedial to the normal testes and slightly smaller in size(approx.2.4x1.8cm).A well defined epididymis was present .Right testis measured approx.3.7x2.9cm and left testis measured approx.4.2x3.0 cm. The findings were compatible with supernumerary testis.


Discussion:

It is a rare congenital anomaly. Normally at about 6 weeks of embryonic life, the primordial testis develops from the primitive genital ridge medial to the mesonephric ducts. By 8 weeks, the primordial testis takes shape and the epididymis and vas deferens arise from the mesonephric (wolffian) duct.5The exact mechanism for occurrence of polyorchidism is not known, but longitudinal or transverse division of the genital ridge, possibly by development of peritoneal bands, has been proposed.5–7

In most cases of polyorchidism, a single supernumerary testis (triorchidism) is present, with the left side being more frequent.6 Bilateral supernumerary testis have also been reported.8,9,10 The most common location of the supernumerary testis is within the scrotum,5 superior or inferior to the ipsilateral testicle.

Most patients with polyorchidism are adolescents or young adults with mean age ranging from15 to 25 years.11 In uncomplicated cases, patients have a painless scrotal mass, which the patients may have noted for a long time. Approximately 40% of cases of polyorchidism occur in association with cryptorchidism. Fifteen percent of cases of polyorchidism may be found in association with testicular torsion.11-16 The entire contents of the ipsilateral hemiscrotum may be twisted,13,14 or only the supernumerary testicle may be twisted.11

In this type of congenital anomaly most patients are asymptomatic and presented with scrotal or groin mass.6 Conditions like infertility, indirect inguinal hernia, torsion, epididymitis, malignancy, hydrocele or varicocele may accompany the supernumerary testes. 17-21


Leung6 classified supernumerary testes into four types on embryological basis:

Type-I: supernumerary testis lacks an epididymis or vas and has got no attachment to the usual testis. (Division of genital ridge only).

Type-II: The supernumerary testis drains into epididymis of usual testis and they share a common vas. (Division of genital ridge occurs in the region where the primordial gonads are attached to the metanephric ducts, although the mesonephros and metanephric ducts are not divided, i.e.-incomplete division).

Type-III: the supernumerary testis has its own epididymis and both epididymis of the ipsilateral testes draining into one vas. (Complete transverse division of mesonephros as well as genital ridge).

Type-IV: complete duplication of testes, epididymis and vas. (Vertical division of genital ridge and mesonephros).

According to Leung the Type-II is the commonest and Type-II and Type-III together account for more than 90% cases of polyorchidism.

 
Singer et al7 suggested an anatomical as well as functional classification based on reproductive potential of the supernumerary testis.

Type 1, the supernumerary testis has reproductive potential because of attachment to a draining epididymis and vas deferens.(Leung type II,III and IV)

Type 2, the supernumerary testis has no reproductive potential because of lack of a draining system.

Singer et al further subclassified these types into Group A, if the supernumerary testis is located in the scrotum(orthotopic), or B, if it is outside (ectopic).

The typical sonographic feature of polyorchidism is a scrotal mass that has an echo texture identical to that of the ipsilateral testicle. The supernumerary testicle may be superior or inferior to the ipsilateral testicle. The supernumerary and ipsilateral testicles may appear attached or separated. . Color Doppler sonography of the supernumerary testicle shows flow characteristics similar to those of the ipsilateral testicle.22 A supernumerary epididymis adjacent to the supernumerary testicle may be seen. The supernumerary testis is of different echogenicity and appears distinct from the adjacent epididymis, and it should not be confused with an enlarged portion of the epididymis. Conceivably, an epididymal or other extratesticular mass may have the same echogenicity as the testis, but is unlikely to have bridging vessels with the testis. Of course, the presence of a mediastinum would confirm a supernumerary testis.

Current treatment of polyorchidism is conservative5,22,23 in the absence of complicating conditions. Orchiectomy and biopsy of the supernumerary testicle for diagnosis or follow-up are not indicated.22 However, in the presence of coexisting conditions, such as testicular torsion, cryptorchism, and malignancy, surgical treatment is warranted. Close sonographic observation in cases of polyorchidism is also advised.

In summary, polyorchidism is a rare congenital anomaly, which often appears as a painless scrotal mass or may be found as an incidental finding on sonography. There are characteristic sonographic features of polyorchidism. In most cases, clinical suspicion along with sonography is diagnostic. Conservative treatment is advised in uncomplicated cases.

Dr Sanjeeb Sharma