Neurofibroma of the external genitalia, extreme enlargement of the clitoris

Abstract

Neurofibromatosis of the genitourinary tract is rare, with a prevalence of 0.65%, and it is exceedingly rare to involve the external genitalia. Involvement of the clitoris, labia majora, and prepuce was reported with clitoromegaly being the most frequently occurring. Herein, we are reporting the case of a 6-year-old girl who was diagnosed with a neurofibroma of the clitoris; measuring 9.4 cm in its largest dimension. To the best of our knowledge, this is the largest clitoral neurofibroma reported in the literature. Due to the rarity of such cases and reports limitations in the literature, the diagnosis of neurofibroma of the external genitalia requires a high index of suspicion by health-care providers. Surgical excision and postoperative follow-up for possible recurrence remain the gold standard of management.

INTRODUCTION

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder, affecting approximately 1:3000 individuals worldwide.[1] The disorder occurs due to a mutation of a gene located on chromosome 17.[1] NF1 has an impact on multiple organs predisposing the affected individuals to benign and malignant tumor formation.[2] It is characterized by multiple pigmented cutaneous lesions (café au lait spots) and multiple subcutaneous tumors arising along the course of the peripheral nerves.

NF of the genitourinary tract is extremely rare, with a prevalence of 0.65%, and it is exceedingly rare to involve the external genitalia.[3] Involvement of the clitoris is the most frequently reported.[4] We present the largest clitoral neurofibroma reported in the literature, measuring 9.4 cm in its largest dimension on magnetic resonance imaging (MRI).

CASE REPORT

We are reporting the case of a 6-year-old girl who was labeled to have ambiguous genitalia. Initially, she was born with mild clitoral swelling. She has a history of genital ambiguity in her family.

The patient had been evaluated by an endocrinology service and there were no hormonal or adrenal abnormalities [Table 1]. Her chromosomal analysis is 46, XX with no apparent abnormalities.

Table 1.

Hormonal profile at the time of diagnosis

Hormone	Serum level
ACTH	9 ng/L
Cortisol	156 nmol/L
GH, random	5.31 ng/mL
FSH	3.6 IU/L
LH	0.3 IU/L
A17-hydroxyprogesterone	<0.4 nmol/L
Testosterone	<0.087 nmol/L
11-deoxycorticosterone	<5.0 ng/dL
TSH	5.44 mU/L

ACTH: Adrenocorticotropic hormone, GH: Growth hormone, FSH: Follicle-stimulating hormone, LH: Luteinizing hormone, TSH: Thyroid-stimulating hormone

With time, the clitoral swelling progressed in size. A pelvic MRI study showed a large exophytic soft-tissue mass centered at the clitorial region measuring 9.4 cm × 4.6 cm × 3.7 cm in oblique craniocaudal, anteroposterior, and transverse dimensions, respectively, with encasing the urethra without deep extension [Figure 1]. The features were most consistent with a plexiform neurofibroma, especially with the presence of more than 6 café au lait macules measuring more than 0.5 cm distributed among her skin.

Figure 1.

(a) Sagittal section of pelvic MRI showing a large clitoral mass containing numerous tiny individual nodules. (b and c) Axial and coronal sections show a soft-tissue mass centered at the clitorial region encasing the urethra. MRI: Magnetic resonance imaging

Adrenal cortical hyperplasia and ovarian, bladder, and ureter involvement were excluded.

Under general anesthesia, pelvic examination revealed a disfiguring clitoral mass measuring with lobular consistency [Figure 2] with normal labia majora, normal urethral, and vaginal orifice.

Figure 2.

Intraoperative photography demonstrating cliteromegaly

Cystoscopy and vaginoscopy were done and they demonstrated normal vagina and urethra with no mass protrusion. Hence, the decision was made to remove the whole clitoris up to the corporal cavernosal base by removing all the suspicious subcutaneous fatty tissue in the pubic area [Figure 3].

Figure 3.

Completely excised clitoral mass

Three months after the procedure, the patient was doing well with almost normal appearing external genitalia with no signs of recurrence.

DISCUSSION

The first case of clitoral neurofibroma was reported in 1960 by Haddad and Jones.[5] In a recent review of the literature, we found around 44 reported cases of NF1 with genitalia involvement, 30 females and 14 males. Out of the 30 females, 18 had clitoral involvement.[3] The age of the patients in the reported cases ranges from 3 to 15 years.[3]

The largest clitoral mass was reported in 2008 and it measured 6.5 cm long mass on physical examination.[3] Therefore, and to the best of our knowledge, the present case is the largest NF of the clitoris reported in the literature.

Workup of clitoral enlargement must exclude hormonal and nonhormonal causes including congenital adrenal hyperplasia, precocious puberty, virilizing tumor, and NF. In our case, the patient was initially referred to an endocrine clinic to exclude possible endocrinological etiology.

Although rare, NF of the genitourinary tract should be kept in mind when evaluating a child with genitourinary tract abnormalities. Diagnosis of NF1 can be made in the absence of family history by meeting two of the National Institutes of Health diagnostic criteria of neurofibroma.[6] Our patient did not have a family history of NF; however, she met two diagnostic criteria.

Therefore, careful physical examination to detect early signs of NF1 is important. Furthermore, prompt and early diagnosis is crucial as it will allow early management and prevention of the destruction of adjacent structures and further complications.

Most of the reported clitoral involvement demonstrates solitary plexiform neurofibroma, which is consistent with our present case.

Surgical resection with clitoroplasty at the time of diagnosis has been regarded as the treatment of choice for children with clitoral hypertrophy to preserve the neurovascular bundle and glandular tissue.[7] In addition, regular postoperative monitoring for local recurrence is recommended.[7] Although no recurrences have been reported within 1 year of follow-up in the reported cases. In the present case, we followed the suggested management, complete excision was done, and regular follow-up was arranged with the patient.

CONCLUSION

Due to the rarity of such cases and reports limitations in the literature, the diagnosis of neurofibroma of the external genitalia requires a high index of suspicion by health-care providers. Surgical excision and postoperative follow-up for possible recurrence remain the gold standard of management.

Consent

Informed consent was obtained from the patient’s guardian for publication of this case report.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the legal guardian has given his consent for the child’s images and other clinical information to be reported in the journal. The guardian understands that his name and initials will not be published and due efforts will be made to conceal his identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.