Melanocytic schwannoma: The cytologic aspect in fine‐needle aspiration cytology (FNAC): Report of a case located in the spinal cord

Abstract

We describe a case of intramedullary melanocytic schwannoma (MS) studied by means of fine-needle aspiration cytology (FNAC). The main cytologic features were (1) large three-dimensional clusters overshadowed by heavy pigment deposits which tested positive for Fontana Masson (and bleached with potassium permanganate), HMB-45, Vimentin, and S-100 protein; (2) loose syncytial monolayered sheets with very little pigment deposit; and (3) isolated spindle cells with polarized nucleus and tapered, thin cytoplasmic ends. Both the cytologic features and the immunophenotypic profile were nonspecific and on their own were insufficient to allow the diagnosis of MS to be reached. Clinical data and the magnetic resonance image (MRI) in conjunction with the cytologic findings did suggest the diagnosis of intramedullary MS.

Intramedullary melanotic schwannoma of the conus medullaris: a case report

“…The interest of this case lies in its peculiarity of being localized inside the conus medullaris. [2][3][4][5][6] Since a few hypothesis regarding intramedullary melanotic schwannomas' origin were previously advanced, their applicability to this case is verified.…”

Cytologic Findings in Pigmented Melanotic Schwannoma

“…[8][9][10] The differential diagnosis of PMS also includes pigmented lesions such as pigmented neurofibroma, psammomatous meningiomas, ancient schwannomas, leptomeningeal neurocytoma and malignant melanoma both primary or metastatic. [11][12][13][14][15][16] Neurofibromas are often diffuse, may show only microscopic pigmentation and lack psammoma bodies and fat. Their nuclei are small and fusiform, whereas those of PMS are round with distinct central nucleolus.…”

“…[8][9][10] To our knowledge, there are few reports describing PMS on fine needle aspiration cytology. [11][12][13][14] Case A 37-year-old man presented with an 8-month history of lower back pain. Physical examination was unremarkable for stigmata of Carney's complex.…”

Cytoarchitectural Findings in the Diagnosis of Primary Soft Tissue Tumors

“…131,147 This lesion, the behavior of which is unpredictable, with recurrences and occasional metastases, is more often seen in the spinal nerve roots and sympathetic chains of middle-aged people; at least 50% of lesions containing psammoma bodies are found in patients with Carney's syndrome. 22 In both cases reported in the literature, aspirate was composed of tissue fragments with …”

“…Cells displayed an oval nucleus, often with a longitudinal fold, prominent nucleolus and abundant, elongated cytoplasm containing brown melanotic pigment ( Figure 19). 131,147 …”