Nodular fasciitis on the zygomatic region: a rare presentation
A 24-year-old, brown-skinned female presented with a nodule on the right zygomatic\nregion, of progressive growth for 3 months, without previous traumas, inflammatory\nprocesses or local symptoms.\nPhysical examination revealed a nodule measuring around one centimeter in diameter, of\nfirm consistency, regular shape and movable in relation to the skin and deep tissues. No\nlymphadenomegaly was observed. Patient was in good health, with no evidence of systemic\ninvolvement. Main diagnostic hypotheses were epidermoid cyst, trichilemmal cyst and\npilomatrixoma.\nExcisional biopsy was carried out and macroscopically pointed to a irregularly-shaped\nwhite-yellow mass 1.0 x 0.6 cm in diameter ().\nHistopathological examination showed a non-encapsulated proliferation of mesenchymal\ntissue with irregular edges and spiky contours, extending from the dermis to hypodermis.\nThe lesion consisted of thin spindle cells forming bundles in several directions,\ninterposed by thick and hyaline collagen fibers, without cell atypias. Areas of myxoid\naspect, extravasation of erythrocytes and discrete lymphoid infiltrate were also\nobserved. ()\nImmunohistochemical studies were performed with antibodies to CD34, desmin,\nmuscle-specific actin (HHF35), smooth muscle actin (SMA) and Ki-67. The lesion\ndemonstrated immunopositivity for HHF35 and SMA and was slightly positive for Ki-67\n( to ).\nClinical, anatomopathological and immunohistochemical findings taken together led to the\nconclusion that the excised lesion was nodular fasciitis.