Nodular fasciitis: A frequent diagnostic pitfall on fine‐needle aspiration

Abstract

BACKGROUND: Nodular fasciitis (NF) is a benign, self-limited, fibroblastic/myofibroblastic proliferation that is diagnostically challenging, often mimicking a malignant process due to its rapid growth clinically and its high cellularity, mitotic activity, and variable/nonspecific cytomorphologic findings. Herein, the authors report what to their knowledge is the largest and first multi-institutional study of the cytomorphologic characteristics of NF by fine-needle aspiration (FNA). METHODS:The pathology archives at The Johns Hopkins Hospital, The Ohio State University Wexner Medical Center, and Emory University Hospital were searched for soft tissue FNA cytology specimens of masses confirmed to be NF. The clinical history, actual FNA diagnosis, and cytomorphologic features were recorded by the authors. RESULTS: A total of 34 patients were identified, 33 of which had material available for review. The mean age of the patients was 40 years (range, 1-80 years); 18 patients (52.9%) were male. The mean duration of symptoms was 3.75 months. Four cases (11.8%) and 2 cases (5.9%) were signed out as NF and "malignant neoplasm, NOS [not otherwise specified]," respectively. On average, cases were hypercellular (mean, 3.27/4). Thirty cases (90.9%) contained spindled morphology, whereas 30 cases (90.9%) and 28 cases (84.4%) contained cells with unipolar and curved cytoplasmic tails, respectively. Eccentric, ovoid, and spindled/elongated nuclei were observed in 31 cases (93.9%), 30 cases (90.9%), and 29 cases (87.9%), respectively.Nineteen cases (57.6%) lacked atypia. CONCLUSIONS: In the current study, the diagnosis of NF was suggested in nearly 40% of cases. Combining the clinical presentation with the most commonly described cytomorphologic features will appropriately triage the majority of cases, although uncertainty will remain in a significant number of cases. Cancer Cytopathol 2017;125:20-9.

Nodular fasciitis of the parotid gland: A challenging diagnosis on FNA

“… These cases were previously published and described as cases 7, 9, 11, 12, and 13, respectively, in our prior study …”

“…A total of 15 cases involving the parotid gland were identified; they included 2 that were unavailable for cytomorphologic review and 5 that had been previously reported by the authors in a separate study but were re‐reviewed for inclusion in the current study . The demographics, clinical presentation, and FNA diagnoses for each case are summarized in Table .…”

“…To avoid unnecessary parotidectomy for NF with its attendant risk for serious complications, including facial nerve transection, it is essential to identify the possibility of NF on FNA. Although there are several reports characterizing the FNA findings in NF, the cytomorphology has not been systematically evaluated in the parotid gland . This study characterizes the clinical and cytomorphologic findings of NF of the parotid gland by FNA to facilitate better preoperative recognition of this entity.…”

“…Because no unique radiographic features of NF have been reported to date on ultrasound, computed tomography (CT), or magnetic resonance imaging (MRI), minimally invasive sampling of the lesion is often performed to assess the need for surgery . However, NF can be easily mistaken for an aggressive neoplasm on fine‐needle aspiration (FNA) because of its high cellularity and somewhat nonspecific cytomorphology, and this can lead to patient anxiety and aggressive management . This challenge is especially acute in the parotid gland, where NF can show morphologic overlap with a wide range of benign and malignant neoplasms.…”

Cytopathologic characteristics of HPV‐related small cell carcinoma of the oropharynx

“…The pathologic diagnoses, cytomorphologic characteristics, immunocytochemical stains, and ISH studies were reviewed and recorded for all available cases. The overall specimen cellularity was assessed with a 4‐point scale like the one reported by Othman et al and used previously by Allison et al as follows: 1 = scant, 2 = hypocellular, 3 = moderately cellular, and 4 = hypercellular.…”