Discussion
Nodular fasciitis is known to be a rear tumor of the vulva. There is only one published case of a recurrence of vulvar nodular fasciitis [8]. This case illustrates the importance of making the distinction between nodular fasciitis and malignant soft tissue tumors, as their differing risks must be matched with appropriate clinical intervention, adjuvant treatment, and follow-up regimen to avoid undertreatment or overtreatment. The pathologist must recognize the possibility of nodular fasciitis even in unusual sites and avoid misdiagnosis of malignancy. This case highlights that recurrence does not always indicate malignancy and can result due to the incomplete initial surgery. The importance of immunohistochemistry is also demonstrated in this case, as histology alone does not exclude other neoplasms in the differential diagnosis (Table 1).
The pathogenesis of nodular fasciitis is unclear, though some suggest antecedent trauma may occur. While the precise incidence in the general population is unknown, it has been described mainly in young and middle-aged adults in the 4th and 5th decades. Clinically, as in our patient, it is characterized by rapid growth, pain, and size <3 cm [3,9].
An important component to optimal health care delivery is the ability to consult experts in related subspecialties or on rare tumors in real time. The monthly international tumor board videoconference facilitated by one gynaecologic oncology professional society, the International Gynaecologic Cancer Society, allows collaboration and accurate diagnosis among gynaecologic oncologists, pathologists, and others. This is a model that may be emulated across the world in various regions and disciplines to improve diagnosis and patient care.
While more common diseases of the vulva include angiomyofibroblastoma, cellular angiofibroma, aggressive angiomyxoma, superficial angiomyxoma, lipoma, and smooth muscle neoplasms (i.e., leiomyoma or leiomyosarcoma) [10], the clinician should recognize that nodular fasciitis may occur in the vulva, and the incidence may be more frequent than previously recognized [8].
Acknowledgements:We would like to acknowledge the International Gynecologic Cancer Society and its ECHO project, in collaboration with the MD Anderson Cancer Center; Anna Plotkin MD (Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, CA); Jubilee Brown MD (Division of Gynecologic Oncology, Levine Cancer Institute at Atrium Health, Charlotte, NC, USA
Conflict of Interest: The authors report no conflict of interests to declare.
Ethical approval: We have reported this case in compliance with the Declaration of Helsinki. Written informed consent was obtained from the patient.
Data availability statement: The data that support the findings of this study are available from the corresponding author upon reasonable request.