The Cyclist Nodule, a rare vulvar entity. The patient was a 30-year-old healthy nulliparous woman with no past medical or surgical history who presented to her gynecologist for an annual exam. She endorsed having a lump on her vulva for one year, which was occasionally painful. She denied any dyspareunia, vaginal discharge, or dryness. Pelvic exam was notable for a soft, non-tender, fluctuant mass on the right labia magus, 6 centimeters in length. Given the patient's symptoms and need for histopathologic evaluation of the mass, the patient underwent an exam under anesthesia, an excision of her right vulvar mass. Interoperative findings were notable for an 8-centimeter vulvar mass with a 1-centimeter stalk. There was no evidence of a double lumen. However, there was an appreciable cord within the pedicle. We will now review the surgical approach used to excise the lesion. One percent lidocaine with epinephrine is injected circumferentially around the base of the lesion along the planned area of the incision. The margins of the pedunculated stalk are outlined, and a scalpel is used to incise the skin circumferentially along the base of the lesion. The initial incision is carried down sequentially with careful assessment of each layer until the entirety of the stalk is severed. 3-O monocryl is used to re-approximate the subcutaneous tissue so that the skin edges are not on tension. Subsequently, a 4-O monocryl suture is used in an interrupted fashion to re-approximate the skin. The labium magus appeared within normal limits at the completion of the procedure. It is important to ensure that there is no evidence of visceral or vascular injury during the excision of the lesion. Topical skin adhesive is then applied over the incision site. Pathology was notable for a benign fibroblastic and myofibroblastic proliferation mixed with collagen bundles, suggestive of a cyclist nodule. Immunohistochemistry was notable for focally positive desmin in positive estrogen receptor, progesterone receptor, and CD34. The cyclist nodule is also known as a reactive fibroblastic and myofibroblastic proliferation of the vulva. The lesion is believed to result from microtrauma from pressure and vibration between the ischial tuberosities and the saddle, resulting in local injury to the tissue with resultant reparative and reactive proliferation of fibroblasts and myofibroblasts. The latency period may vary from several weeks to one year. The lesion is poorly described among women and was historically thought to occur exclusively among male cyclists, though six cases in women have been reported. Usual pathologic features are notable for a haphazard admixture of adipose tissue, as well as variably cellular hyalinized tissue containing fibroblasts, vascular channels, and nerve fibers. Immunophenotyping is helpful to exclude other lesions. The classic presentation of the cyclist nodule is pain and pressure when sitting on the saddle, a common complaint among cyclists experiencing this phenomenon, as well as unilateral vulvar hypertrophy noted on the exam. The nodular mass may exhibit a fibrous to elastic consistency and may be mobile or fixed to the soft tissue or ischial tuberosity. In males, nodules on each side of the raphe posterior to the scrotum are characteristic and are also referred to as a third testicle. Workup of the cyclist nodule includes a full clinical history and examination to identify the location of the lesion. Imaging such as ultrasound is primarily used to obtain the exact extent of the lesion, which characteristically demonstrates a hypoechoic solid nodule without increased Doppler signal. The differential diagnosis for this type of lesion includes an epidermal cyst, abscess, massive localized lymphedema, as well as tumor, including a fibroma, soft tissue sarcomas, or metastasis. Management options include conservative management with intralesional corticosteroid or hyaluronidase injection for small nodules, though surgical excision remains the mainstay of treatment. It is also important to counsel the patient that the lesion may recur even after complete surgical excision and has been reported to recur as early as seven months following excision. In conclusion, this is the case of a poorly recognized vulvar lesion that may present among our patient population. The risk for misdiagnosis is high as the vulva is a potential site for the development of a wide range of mesenchymal lesions. As the prevalence of cycling among women increases, the cyclist nodule should be added to the list of differential diagnoses of the clinician treating similar perineal nodular lesions.

Cyclist Nodule

Vulvar lump

Exam under anesthesia

Benign fibroblastic proliferation

Perineal nodular lesions