Ancient neurilemmoma: A rare oral tumor
A 22-year-old male patient reported to the dental facility with a growth in the right back tooth region of his mouth, He had noticed the start of the growth 6 months ago. The lesion was stated to be painless and slow growing. On intraoral examination there was a nodular soft tissue mass in the mucobuccal fold region, in the right posterior maxillary quadrant above the molars. It was about 2 × 2 cm in size, smooth, sessile, non-tender and firm on palpation, with slight bleeding on manipulation. A provisional diagnosis of pyogenic granuloma was made []. The patient consented to surgical excision and the surgery was performed after general clinical and routine laboratory investigations. He is being followed-up regularly for the past 3 months and progress has been uneventful.\nThe cut-section of the excised tissue revealed a solid lesion with hemorrhagic areas []. On histopathological examination, the lesion presented as a circumscribed cellular mass []. The cells were mostly spindle shaped with oval/blunt elongated nuclei. They were arranged in two patterns. One pattern was a palisaded arrangement of cells encircling eosinophilic structures (suggestive of Verocay bodies) []; and the other pattern was an irregularly arranged configuration of spindle cells, sometimes in a loose myxoid background [Figure and ]. These patterns appeared consistent with descriptions of Antoni A and Antoni B patterns observed in schwannomas. There was significant vascularity throughout the lesion, with thick-walled blood vessels surrounded by hyalinization and inflammatory cells [Figure and ]. Extravasated red blood cells (RBCs), hemosiderin deposition and siderophages were occasionally encountered []. In some areas, the spindle cells revealed nuclear pleomorphism and increased nuclear cytoplasmic ratio [Figure and ]. Mitotic activity was insignificant, with mitotic index (MI) <1 per high power field (HPF). No abnormal or bizarre mitotic figures were observed.\nTaking into account the above features of schwannoma, along with extensive hemorrhage, hemosiderin deposition and cellular atypia, a histopathological diagnosis of ancient schwannoma was given.