Malignant transformation of intrathoracic ancient neurilemmoma in patient without von Recklinghausen disease

초록

Malignant transformation of a neurilemmoma exceedingly rare event. We described a case of intrathoracic ancient neurilemmoma undergoing malignant change in a 39-year-old man. The patient was presented with right flank and chest pain for several months. Plain X-ray and CT scan of the chest showed soft tissue mass lesion at extrapleural space with erosion of surrounding rib at right basal lung area. The excised mass was encapsulated and measured 4.5x3.5x2.3cm. The cut surface showed grayish-white and glistening with focal cystic change and hemorrhage. Necrosis was not seen. Histologically, the tumor showed the features of classic neurilemmoma composed of Antoni type A and B area with perivascular hyalinization. In addition, obviously histologically malignant foci manifested by presence of markedly increased cellularity with fascicular arrangement, active mitotic activity, hyperchromasia and gradual loss of original neurilemmomatousfeature. Review of the available literature revealed only a few other similar cases documenting malignant transformation of solitary benign neurilemmomas in patients without von Recklinghausen disease.