Mid-thoracic Nodular Fasciitis: A Diagnostic Dilemma

Abstract

Nodular fasciitis (NF) is a rare, benign, yet rapidly proliferative myofibroblastic soft tissue tumor that often mimics malignant lesions and presents significant diagnostic challenges. This case report describes a 16-year-old female whose mid-thoracic mass was initially mismanaged in an emergency setting as a sebaceous cyst. The misdiagnosis and subsequent inappropriate incision and drainage led to an iatrogenic flare-up, exacerbating the patient's condition and complicating her management course. The complexities encountered in this case underscore the critical need for stringent diagnostic protocols and multidisciplinary management to avoid iatrogenic complications and improve clinical outcomes in patients presenting with unusual soft tissue lesions. This report highlights the importance of adhering to established protocols for soft tissue lump evaluation and the potential pitfalls of misdiagnosis.

Keywords: diagnostic challenge; misdiagnosis; myofibroblastic proliferation; nodular fasciitis; soft tissue mass.

Figure 1. Pre-operative image displaying protruding erythematous cauliflower-like mass over mid-thoracic region at I&D site

I&D: Incision and drainage

Figure 2. MRI spine sagittal T2 view showing a heterogenous exophytic mass over the subcutaneous soft tissue plans at posterior midline mid thoracic with contrast enhancement suspicious for infiltration

Figure 3. Microscopic examination with H&E Stain depicts haphazard proliferation of bland myofibroblastic spindled cells in tissue culture arrangement with multifocal microcystic changes in myxoid stromal background with scattered erythrocytes

Figure 4. Diagnostic algorithm for the evaluation of painless soft tissue mass