Bai-zhou Li1, Jia-wei Wang, Hong-quan Wei. 1. Department of Pathology, the Second Affiliated Hospital of Zhejiang University Medical College, Hangzhou 310009, China.
Abstract
OBJECTIVE: To study the morphologic characteristics, immunophenotype and differential diagnosis of a case of microcystic/reticular schwannoma occurring in cervical spine. METHODS: The pathologic features and immunophenotypic profile of a case of microcystic/reticular schwannoma were studied. Immunohistochemistry was performed using EnVision two-step method. RESULTS: The patient was a 35-year-old male and presented with a bump over the fifth cervical spine on radiologic check up. Grossly, the bump was gray-white in color, soft, well-circumscribed but non-encapsulated. The tumor measured 3.5 cm × 3.0 cm × 1.8 cm in size. Histologically, it was composed of two distinctive components. One component resembled the conventional schwannoma but showed focally nuclear pleomorphism, reminiscent of changes in degenerating schwannoma. The other component consisted of epithelial-like cells arranged in a reticular or lace-like pattern, amongst a myxoid matrix. Immunohistochemical study showed that the tumor cells were strongly positive for vimentin, S-100 protein, glial fibrillary acidic protein and neuron-specific enolase, focally positive for CD68, CD10 and Ki-67, and negative for pan-cytokeratin, epithelial membrane antigen, neurofilament, carcinoembryonic antigen, smooth muscle actin, estrogen receptor, progesterone receptor and p53. CONCLUSIONS: Microcystic/reticular schwannoma is a novel variant of schwannoma, arising mainly in internal viscera but seldom in bone. Awareness of this entity is helpful in distinction from chordoma, other mucoid tumors or sarcomas.
OBJECTIVE: To study the morphologic characteristics, immunophenotype and differential diagnosis of a case of microcystic/reticular schwannoma occurring in cervical spine. METHODS: The pathologic features and immunophenotypic profile of a case of microcystic/reticular schwannoma were studied. Immunohistochemistry was performed using EnVision two-step method. RESULTS: The patient was a 35-year-old male and presented with a bump over the fifth cervical spine on radiologic check up. Grossly, the bump was gray-white in color, soft, well-circumscribed but non-encapsulated. The tumor measured 3.5 cm × 3.0 cm × 1.8 cm in size. Histologically, it was composed of two distinctive components. One component resembled the conventional schwannoma but showed focally nuclear pleomorphism, reminiscent of changes in degenerating schwannoma. The other component consisted of epithelial-like cells arranged in a reticular or lace-like pattern, amongst a myxoid matrix. Immunohistochemical study showed that the tumor cells were strongly positive for vimentin, S-100 protein, glial fibrillary acidic protein and neuron-specific enolase, focally positive for CD68, CD10 and Ki-67, and negative for pan-cytokeratin, epithelial membrane antigen, neurofilament, carcinoembryonic antigen, smooth muscle actin, estrogen receptor, progesterone receptor and p53. CONCLUSIONS:Microcystic/reticular schwannoma is a novel variant of schwannoma, arising mainly in internal viscera but seldom in bone. Awareness of this entity is helpful in distinction from chordoma, other mucoid tumors or sarcomas.