PURPOSE: The purpose of this article is to describe what is probably the first reported case of a melanotic schwannoma of the choroid and to discuss the clinical and histopathologic features that serve to differentiate this rare intraocular tumor from a malignant melanoma of the choroid. PATIENT AND METHODS: A 21-year-old woman underwent enucleation of the right eye for a slowly enlarging pigmented choroidal mass that was associated with ipsilateral blindness. The tumor was studied by light microscopy, immunohistochemistry, and electron microscopy. FINDINGS: The tumor was composed of fascicles and whorls of pigmented and nonpigmented plump spindle cells that had light microscopic features of a schwannoma. The tumor cells showed immunoreactivity to S-100 protein and HMB-45. Electron microscopy showed cytoplasmic processes surrounded by a continuous basement membrane and abundant extracellular collagen. The pigmented spindle-shaped cells contained melanosomes in different stages of melanogenesis. The findings were compatible with a melanotic schwannoma. CONCLUSION: Melanotic schwannoma has been reported in soft tissues, peripheral nerves, and in the orbit. To the authors' knowledge, this is the first report of a melanotic schwannoma of the choroid. This extremely rare pigmented choroidal tumor may be very difficult to differentiate clinically from choroidal melanoma.
PURPOSE: The purpose of this article is to describe what is probably the first reported case of a melanotic schwannoma of the choroid and to discuss the clinical and histopathologic features that serve to differentiate this rare intraocular tumor from a malignant melanoma of the choroid. PATIENT AND METHODS: A 21-year-old woman underwent enucleation of the right eye for a slowly enlarging pigmented choroidal mass that was associated with ipsilateral blindness. The tumor was studied by light microscopy, immunohistochemistry, and electron microscopy. FINDINGS: The tumor was composed of fascicles and whorls of pigmented and nonpigmented plump spindle cells that had light microscopic features of a schwannoma. The tumor cells showed immunoreactivity to S-100 protein and HMB-45. Electron microscopy showed cytoplasmic processes surrounded by a continuous basement membrane and abundant extracellular collagen. The pigmented spindle-shaped cells contained melanosomes in different stages of melanogenesis. The findings were compatible with a melanotic schwannoma. CONCLUSION:Melanotic schwannoma has been reported in soft tissues, peripheral nerves, and in the orbit. To the authors' knowledge, this is the first report of a melanotic schwannoma of the choroid. This extremely rare pigmented choroidal tumor may be very difficult to differentiate clinically from choroidal melanoma.
Authors: D Mahato; T Vivas-Buitrago; K Gassie; M Jentoft; D Tavanaiepour; A Quiñones-Hinojosa Journal: J Neurooncol Date: 2017-11-02 Impact factor: 4.130