Vulvar papule in patient with lichen sclerosus

What is known about this subject in regard to women and their families? Traumatic neuromas most commonly occur on the lower extremities after trauma, although a handful of cases have been reported in the vulva in association with episiotomy scars, traumatic falls, and female genital mutilation. What is new from this article as messages for women and their families? Vulvar traumatic neuroma may occur in the setting of chronic inflammation from lichen sclerosus without associated trauma. Case summary A 74-year-old female with a history of vulvar lichen sclerosus presented for follow-up. She was well-controlled on clobetasol 0.05% ointment twice weekly alternating with estradiol 0.01% cream twice weekly without any new concerns. She denied any trauma to the vulva or sexual activity. On examination, there was a white, firm 0.9 cm papule on the right labium majus (Fig. 1). A skin biopsy revealed hyperkeratosis and homogenized collagen bundles in the papillary dermis with underlying lymphocytic inflammation (Fig. 2A). There was also a haphazard proliferation of nerve bundles in the dermis with a surrounding fibrous stroma (Fig. 2B).Fig. 1.: White, firm 0.9 cm papule on the right labium majus (black arrows).Fig. 2.: (A) Hyperkeratosis with homogenized collagen and lymphocytic inflammation in the papillary dermis and underlying dermal nodule (hematoxylin and eosin, ×4 original magnification). (B) Dermal nodule composed of haphazard proliferation of nerve bundles with a surrounding fibrous stroma (hematoxylin and eosin, ×20 original magnification).Question 1 What is your diagnosis? A. Squamous cell carcinoma B. Traumatic neuroma C. Solitary circumscribed neuroma D. Gartner's duct cyst E. Neurofibroma Correct answer: B. Traumatic neuroma. The examination and histopathology are consistent with traumatic neuroma. On histology, there is a nonencapsulated lesion with bundles of nerve fibers arranged haphazardly in a fibrous stroma.1 The other answer choices would not demonstrate these histopathologic findings. Discussion Traumatic neuromas are reactive nonneoplastic proliferations of nerve fibers and connective tissue that can occur in response to nerve injury. Clinically, traumatic neuromas typically present as discrete, firm, slow-growing, oval-shaped palpable nodules.2 In our case, examination revealed a white firm papule on the vulva in a patient with a history of vulvar lichen sclerosus (Fig. 1). Due to concern for vulvar intraepithelial neoplasia or squamous cell carcinoma (SCC), histopathologic examination was performed. Although SCC of the vulva can present as a solitary nodule and lichen sclerosus is a known risk factor in SCC pathogenesis, the histopathology results are not consistent with SCC, which would demonstrate proliferations of atypical keratinocytes invading the dermis.3 In contrast, histology for a traumatic neuroma will show a nonencapsulated lesion with bundles of nerve fibers arranged haphazardly in a fibrous stroma (Fig. 2A and B). Immunohistochemistry can also demonstrate neurofilament-positive regenerating nerve twigs with scattered S100-positive Schwann cells and CD34-positive dendritic stromal cells. Few traumatic neuromas of the vulva have been previously reported and these have been in association with episiotomy scars, traumatic falls, and female genital mutilation.1 Our patient's presentation is a unique report of vulvar traumatic neuroma in the setting of chronic inflammation from lichen sclerosus without any associated trauma. This case highlights the importance of vulvar examination and biopsy in making the correct diagnosis. Question 2 What is the most common cause of traumatic neuroma? A. Amputation or surgery B. Chronic inflammation C. Human papillomavirus infection D. Mutations of the RET proto-oncogene E. Nerve entrapment Correct answer: A. Amputation or surgery. Traumatic neuromas most commonly occur on the lower extremities after amputation, surgeries, or other trauma.1 Although traumatic neuromas can occur in the setting of chronic inflammation, it is much less common. The remaining other answer choices are not associated with traumatic neuromas. Question 3 Which of the following has low utility in the diagnosis or management of traumatic neuromas? A. Hematoxylin and eosin staining and immunohistochemistry B. Resection C. Gabapentin or pregabalin D. Ultrasound E. Radiation therapy or chemotherapy Correct answer: E. Radiation therapy or chemotherapy. A traumatic neuroma would not be expected to shrink in response to radiation therapy or chemotherapy. Radiation therapy and chemotherapy are used for the treatment of acoustic or vestibular schwannomas (not traumatic neuromas). The other answer choices can be used in either the diagnosis or management of traumatic neuromas. Conflicts of interest None. Funding None. Study approval N/A Author contributions All authors significantly contributed to the writing of this article. Patient consent Informed written consent was received from all patients for whom photographs are present in the manuscript.