Sobani et al. Journal of Medical Case Reports 2011, 5:244 http://www.jmedicalcasereports.com/content/5/1/244 sternocleidomastoid muscle (SCM). Splaying of his right internal jugular vein was also noted between the SCM and the mass. Multiple sub-centimeter lymph nodes were also noted at level II. Fine-needle aspiration cytol- ogy (FNAC) showed spindle shaped cells with elongated vesicular nuclei and pink cytoplasm admixed with pink fibrocollagenous material suggestive of fibromatosis. Our patient underwent a wide local excision with a right-sided neck dissection. Histopathological analysis of the excised tissue showed spindle cells arranged in sheets and intersecting fascicles with variable collagen deposition. No cytological atypia was noted; however, infiltrative growth was noticed within the entrapped skeletal muscle at the periphery. The lesion showed evidence of vascular proliferation and peripheral lymphocytic infiltration. The above find- ings correlated with a tissue diagnosis of AF. Our patient once again presented with local recur- rence of the mass [Figure 1], not associated with any pain or tenderness, but with complaints of suffocation when lying supine, due to a pressure effect generated by the mass [Figure 1]. Magnetic resonance imaging (MRI) showed a large contrast-enhancing mass, hypointense on T1 and hyper- intense on T2, lying in the lower part of his neck to the right of the midline. It was deep to the SCM on the anterior side, abutting the larynx medially and the para- vertebral muscles and space on the posterior side [Fig- ure 2]. A CT scan showed a large soft tissue density mass measuring about 9.3 × 5.9 × 12 cm, with central necrosis consistent with recurrent fibromatosis in the posterior triangle [Figure 3]. The mass was resected and an extended right neck dis- section was performed. Analysis of the excised tissue revealed spindle cells arranged in whorls and fascicles, with intervening thin walled vessels and extravasation of red blood cells. There was no evidence of atypical mitosis or necrosis; however, focal infiltration of adjacent muscle was noted, favoring benign fibromatosis [Figure 4]. Our patient was followed in the out-patient clinic reg- ularly for 22 months with no evidence of recurrence of disease. No further treatment was given. Page 2 of 4 Discussion AF in the head and neck is a rare benign tumor, thought to arise from connective tissue, fascial sheaths, and other musculoaponeurotic structures of the body [1]. It presents as a progressively enlarging painless lump, fixed to the underlying structures. By virtue of its location it may be associated with trismus, airway obstruction, dysphagia, and proptosis [2]. Intermittent airway obstruction due to pressure effects and gravita- tional position may also occur, as was noted in our case. AF is a slow growing tumor; as such it demonstrates a low level of mitosis and cellular atypia, and distant metastasis has yet to be reported. Its true pathogenic potential lies in its ability to locally invade surrounding structures. This fact is of extreme importance in the head and neck region due to the compact anatomical schematics and close association with vital neurovascu- lar and anatomical structures; however invasion of the neurovascular structures has not been reported [3]. Kruse et al. proposed a classification for AF in the head and neck after reviewing cases reported in the last 40 years, based on the site (such as upper and lower compartment), bone involvement and presence of hor- mone receptors [3]. In their review they found no indi- cators for potential recurrence in relation to age, sex, or localization [3], but the depth of invasion was shown to significantly affect disease-free survival [4]. The main treatment modality is wide surgical excision of the lesion, however in the head and neck region pre- servation of vital structures and their function may impede this objective [5]. Therefore a multi-modality management strategy is usually employed to control residual disease. Surgery is usually combined with radia- tion therapy for control of residual disease and to pre- vent recurrence. Studies have shown that radiation therapy can also be effectively employed independently, leading to a com- plete response in 20%, a partial response in 20%, and stable disease in 53% of cases; supporting evidence that radiation therapy may decrease indications for surgery [6]. In cases of patients undergoing multi-modality treat- ment, including surgical resection and radiation therapy, Figure 1 39-year-old male with a right sided neck mass. Scars from previous excisions are seen. The reccurring mass on examination.