Testicular feminization: role of MRI in diagnosing this rare male pseudohermaphroditism

A novel DEAH-box helicase 37 mutation associated with differences of sex development

OBJECTIVE

To determine the genetic etiology of a family pedigree with two patients affected by differences of sex development (DSD).

METHODS

Assess the clinical characteristics of the patients and achieve exome sequencing results and in vitro functional studies.

RESULTS

The 15-year-old proband, raised as female, presented with delayed puberty and short stature associated with atypical genitalia. Hormonal profile showed hypergonadotrophic hypogonadism. Imaging studies revealed the absence of a uterus and ovaries. The karyotype confirmed a 46, XY pattern. Her younger brother presented with a micropenis and hypoplastic scrotum with non-palpable testis and hypospadias. Laparoscopic exploration was performed on the younger brother. Streak gonads were found and removed due to the risk of neoplastic transformation. Post-operative histopathology showed the co-existence of Wolffian and Müllerian derivatives. Whole-exome sequencing identified a novel mutation (c.1223C>T, p. Ser408Leu) in the Asp-Glu-Ala-His-box helicase 37 gene, which was found to be deleterious by in silico analysis. Segregation analysis of the variant displayed a sex-limited, autosomal dominant, maternal inheritance pattern. In vitro experiments revealed that the substitution of 408Ser by Leu caused decreased DHX37 expression both at the mRNA and protein levels. Moreover, the β-catenin protein was upregulated, and the p53 protein was unaltered by mutant DHX37.

CONCLUSIONS

We described a novel mutation (c.1223C>T, p. Ser408Leu) of the DHX37 gene associated with a Chinese pedigree consisting of two 46, XY DSD patients. We speculated that the underlying molecular mechanism might involve upregulation of the β-catenin protein.

Normal pelvic ultrasound or MRI does not rule out neoplasm in patients with gonadal dysgenesis and Y chromosome material

INTRODUCTION

Patients with gonadal dysgenesis (GD) with a Y chromosome have an increased risk of gonadal neoplasm. Few data exist on the ability of imaging to detect malignancy in intra-abdominal gonads in these patients.

OBJECTIVE

We aimed to determine the correlation between preoperative imaging findings and gonadal pathology in GD patients with Y chromosome material.

METHODS

A retrospective review was performed of patients with XY or XO/XY GD who underwent gonadectomy at our institution from 2003 to 2017. Patients were assessed preoperatively with ultrasonography; some additionally underwent MRI.

RESULTS

The series consisted of 10 patients, all with female gender and non-palpable gonads. Median age was 13.1 years (range 2.4-18.3 years). Overall, four of the ten patients (40%) had a tumor (gonadoblastoma or dysgerminoma) on final pathology. Four patients had a gonad or gonads that were definitively seen on ultrasonography. All visualized gonads were described as "normal" or "small" with the exception of one patient, who had a normal MRI. Three of the four patients in this group had a tumor on final pathology. The remaining six patients had a gonad or gonads that were not definitively visualized on ultrasound; one patient in this group had a tumor on final pathology. Overall, five of seven gonads (71%) definitively visualized on ultrasound had tumor on final pathology, and two of thirteen gonads (15%) not visualized on ultrasound had tumor on final pathology; this difference was statistically significant (p = 0.012). Three patients were imaged with MRI. Of the gonads that could be visualized on MRI, no definitive abnormalities were seen. All patients imaged with MRI had tumors on final pathology.

DISCUSSION

Both ultrasound and MRI are relatively poor at identifying and characterizing intra-abdominal gonads in GD patients. The majority of patients who had a neoplasm had normal imaging findings. Gonads that were definitively visualized on ultrasound were more likely to contain neoplasms that could not be visualized, which perhaps because of tumor growth. No other consistent imaging findings of malignancy were found. Our study included ultrasound evaluations that were completed over 10 years ago and not performed by pediatric ultrasonographers, which may have biased the results. However, results suggest that when discussing gonadectomy with GD patients, one should not be reassured by "normal" imaging findings. Neither ultrasound nor MRI should be relied on for surveillance in GD patients who decide against gonadectomy.

CONCLUSION

A normal ultrasound or MRI does not rule out neoplasm in GD patients with intra-abdominal gonads.

The use of MRI in the pre-surgical evaluation of patients with androgen insensitivity syndrome

BACKGROUND

Patients diagnosed with androgen insensitivity syndrome (AIS) need bilateral gonadectomy (orchiectomy) for malignancy risk reduction. Imaging of the gonads (testicles) prior to surgery is recommended. Ultrasonography has typically been used. However, magnetic resonance imaging (MRI) provides better localization of the gonads and pre-surgical planning.

CASES

In this case series, we describe how MRI was utilized in planning surgical gonadectomy in 3 patients with complete AIS and to review the literature regarding MRI and AIS.

SUMMARY AND CONCLUSIONS

MRI prior to surgery was helpful in localizing and planning for removal of the gonads while preventing injury to other structures. Surgical specialists with experience with inguinal dissection were appropriately consulted when an inguinal dissection was likely to be needed to complete the gonadectomy.

PET imaging of Sertoli cell tumor in androgen insensitivity syndrome

The author presents a case of Sertoli cell tumor demonstrated incidentally by F-18 fluorodeoxyglucose positron emission tomography during imaging workup for suspected right-lung malignant neoplasm. This rare sex cord stromal tumor arose from the right gonad of a patient with a history of androgen insufficiency syndrome, also known as testicular feminization syndrome. The relationship of this phenotypic sexual disorder with Sertoli cell tumor is briefly reviewed and discussed.

Insights into causes of sexual ambiguity

Our understanding of the causes of sexual ambiguity has progressed from the determination of the hormonal etiologies to defining the genetic basis of intersex disorders. The localization of specific genes involved in the process of sexual differentiation has made it possible to determine the mutations and other molecular events that result in sexual ambiguity. With this information, some disorders can now be diagnosed before birth and possibly even treated in utero.

Diagnostic imaging in obstetrics and gynecology: new developments

This article reviews the most recent studies incorporating diagnostic imaging modalities into gynecologic and obstetric care. It describes studies evaluating the utility of various imaging modalities for the diagnosis of fetal abnormalities, uterine and tubal pathology, and staging of gynecologic malignancies. In addition, the article reviews some experimental studies and their potential clinical applications.