Intravascular nodular fasciitis arising from chest wall: a case report with literature review

Introduction: Intravascular fasciitis (IVF) is a rare variant of nodular fasciitis characterized by intraluminal, intramural, and extramural involvement of blood vessels, accounting for less than 3% of all nodular fasciitis cases. Case presentation: A 59-year-old man with a history of treated laryngeal squamous cell carcinoma was found to have a 22-mm nodule in the fifth intercostal space on follow-up computed tomography, which raised clinical suspicion of chest wall metastasis. The patient underwent a left thoracotomy with combined resection of the fifth and sixth ribs. Histologically, spindle cells proliferated in a tissue culture-like growth pattern within a fibromyxoid stroma. Immunohistochemically, the spindle cells were positive for muscle-specific actin (M-actin) and smooth muscle actin and negative for cytokeratins. Break-apart fluorescence in situ hybridization (FISH) demonstrated USP6 rearrangement. Based on these findings and the intravascular involvement of small blood vessels, a final diagnosis of IVF was made. The patient has been followed for 15 months after surgery without any recurrence or metastasis. Discussion: IVF is frequently misdiagnosed as intravascular invasion of a malignant spindle cell neoplasm. In the present case, metastatic carcinoma with sarcomatoid change was initially suspected because of the patient’s history of laryngeal carcinoma. Accurate diagnosis of IVF requires careful evaluation of the histological and immunohistochemical findings, together with confirmation of USP6 rearrangement by FISH. Conclusions: We report a case of IVF arising in the chest wall of a man with a history of laryngeal cancer. When an intravascular spindle cell lesion is encountered, IVF should be considered in the differential diagnosis.