Fibrous connective tissue lesion mimicking a vestibular schwannoma: Case report

OBJECTIVE AND IMPORTANCE: Cerebellopontine angle fibromas are rare patholog ical entities that can mimic the presentation of vestibular schwannomas (VS s). Diagnosis of these benign lesions, however, is important, because treat ment options may be different, The clinical, radiological, and intraoperati ve features of these unusual lesions of the cerebellopontine angle are disc ussed, with review of the relevant literature. CLINICAL PRESENTATION: A 41-year-old man presented with recurrent episodes of diminished hearing on the left side, accompanied by facial ticks and pai n on the same side. Magnetic resonance imaging and computed tomographic sca ns revealed a 1.5-cm, primarily intracanalicular lesion, suggesting a left VS. INTERVENTION: The lesion was partially removed through a retrosigmoid suboc cipital craniotomy. Its intraoperative appearance and hard fibrotic consist ency differed from the classic features of VSs, The pathological findings i ndicated nontumoral fibrous connective tissue. The lesion exhibited no feat ures of inflammation or fat and was also negative for S-100 staining. Follo w-up magnetic resonance imaging scans demonstrated a small residual lesion, which exhibited shrinkage in: subsequent magnetic resonance imaging studie s. The painful ticks disappeared and facial nerve weakness improved postope ratively. CONCLUSION: Although cerebellopontine angle fibromas may present similar ra diological features, their clinical presentation may be somewhat different from that of typical VSs. If a fibroma is suspected, radiosurgery should be avoided; limited surgery may be considered as an option for patients exper iencing symptoms. Because fibromas may be intraoperatively noted to be fibr otic and vascular, radical removal may not be easy or justified. After the final diagnosis has been reached, conservative treatment of the residual le sion may be the best option.