[Fasciitis nodularis pseudosarcomatosa. A difficult differential diagnosis in the head-neck area].

INTRODUCTION: Nodular fasciitis (nF) was first described in 1955 by Konwaler et al. as a benign fibroblastic proliferation. The onset of the disease occurs suddenly as a solitary tumor reaching a size of 10 to 50 mm in a few weeks. Relapse is rare and spontaneous remission frequent. The literature points out histologic similarities to a sarcoma. CASE: The 57 year old female patient presented a spheroid, coarse, nonadherent, slightly painful tumor of the left paramandibular region. The history was inconspicuous. The B-scan sonography revealed a spheroid, anechoic, defined mass of 10-11 mm. The palpatory dimension increased noticeably during the following 2 weeks. Under local anesthesia the suspected lymph node was exposed via intraoral approach. Intraoperatively a non-capsulated, coarse, adherent, spheroid node of 25 mm was resected subtotally to preserve the marginal branch of the facial nerve. Histologically a fibroblastic cell-rich proliferation with mucoid milieu and few mitosis was found. No atypical cells or nuclei were observed and the proliferation reached fascial parts. DISCUSSION: Based on clinical findings the diagnosis nF cannot be proven. Ultrasound and clinical findings suppose a lymphadenopathia, whereas the dynamics points out a malignant tumor. Therefore, histologic assurance after diagnosis is mandatory. In case of vulnerable anatomic structures in vicinity, the absence of a capsule should lead to partial resection despite of a total excision. The histology plays a primary role to avoid surgical overtherapy.