Ultrasound Diagnosis and Surgery Planning for Nuchal-Type Fibroma

Nuchal-type fibroma (NTF) is a rare, benign tumor typically found in the posterior neck but can also appear in extra-nuchal areas such as the face, shoulders, and upper back. It is often poorly circumscribed, which makes it difficult to assess surgical margins for complete excision. The tumor is characterized by dense collagen bundles and sparse fibroblasts, and it may involve surrounding tissues such as adipose tissue, muscle, and nerves, which can complicate surgical intervention. Due to its rarity, there is limited knowledge about the sonographic features of NTF, and the tumor’s proper extension needs to be assessed for successful treatment. This article presents two clinical cases to demonstrate the usefulness of cutaneous ultrasound in diagnosing NTF and aiding pre-surgical planning. The first case involved a 24-year-old male who had a recurrent 2 cm subcutaneous lesion near his right eyebrow after a previous excision. Ultrasound imaging with high-frequency probes revealed a hypoechoic, poorly circumscribed lesion that extended beneath the subcutaneous tissue and muscle, without involving the bone. Color Doppler imaging showed increased vascularization at the lesion’s periphery, indicating enhanced blood flow. Based on these findings, a diagnosis of NTF relapse was made. Mohs micrographic surgery (MMS) was planned, and intraoperative ultrasound was used to assess the surgical margins. After three stages of MMS, the tumor was completely excised. Histological examination confirmed the presence of the tumor with entrapped hypertrophic nerves and adipose tissue. At the three-year follow-up, no recurrence was observed. This case illustrates that ultrasound is a valuable tool for diagnosing NTF, assessing tumor extension, and improving surgical planning, thus reducing the risk of recurrence.