ASNR 2015

Psammomatous Melanotic Schwannoma of The Spine: A Rare Case Report

S Bakan, Y Kayadibi, E Ure, M Asik, Z I Hasiloglu

Istanbul University Cerrahpasa Medical Faculty, Istanbul, Turkey

Presentation number:EP-149

Submission number:1512

Disclosure

• No Disclosures

Background

• Melanotic schwannoma is an intermediate tumor between schwannoma and malign melanoma which are both originates from neuroectodermal tissues.

• These tumors are usually in benign nature but in literature malignant degeneration, recurrence and metastasis had been reported in 26%-38.9% of the cases.

Purpose

• Our purpose in this case report to discuss the imaging findings of a rarely seen psammomatous type of melanotic schwannoma.

Materials & Methods

• A 31-year-old woman admitted to our department with back pain.

• Magnetic resonance (MR) Imaging and computed tomography (CT) were performed for diagnosis.

Results

• MR Imaging revealed a paravertebral, extrapleural soft tissue mass measuring about 2,5 cm that was originating from spinal canal and extending into neural foramen at the level of T4 - T5.

• The mass was containing focal hyperintensity on T1-weighted images and containing a cystic component.

• The lesion was enhancing homogeneously.

Results

• CT showed punctate calcifications inside of this soft tissue lesion.

• Positron emission tomography (PET)/ CT scan revealed an increased FDG.

• Patient underwent surgery and pathological examination revealed spindle- shaped Schwann cells and melanin pigmented cells which were diagnostic for psammomatous type of melanotic schwannoma.

MR Imaging and PET/CT imaging Findings

MR imaging showed a paravertebral, extrapleural soft tissue mass that was originating from spinal canal and extending into neural foramen at the level of T4 - T5. The lesion was hyperintense on T1WI. PET/CT scan revealed an increased FDG.

Discussion

• There are two subtypes of melanotic schwannoma including psammomatous type and sporadic type.

• Psammomatous type of schwannomas coexists within Carney complex (CC) in 50% of cases, so patient should be investigated with further examinations in terms of CC.

Discussion

• Our patient had no clinical and physical findings that was supported CC.

• Melanin containing lesions that including malignant melanoma, melanositoma, pigmented neurofibroma, paraganglioma, leptomeningeal melanosis, hemorrhagic metastatic lesions due to breast cancer, thyroid cancer, choriocarcinoma and lung cancer must be considered in differential diagnosis which are other reasons of T1 shortening.

Conclusion

• In this presentation, we presented a rare case of psammomatous melanotic schwannoma of the spine with its radiological features.

• In fact, there is no characteristic clinical or imaging finding and PET/CT has limited value in differential diagnosis.

• The exact diagnosis could only confirmed by surgery and immunohystopathological examination.

References

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• 2. De Waele M1, Carp L, Lauwers P, Hendriks J, De Maeseneer M, Van Schil P, Blockx P: Paravertebral schwannoma with high uptake of fluorodeoxyglucose on positron emission tomography. Acta Chir Belg 2005: 105:537-8

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• 4. Marton E, Feletti A, Orvieto E, Longatti P: Dumbbell-shaped C-2 psammomatous melanotic malignant schwannoma Case report and review of the literature. J Neurosurg Spine 2007: 6:591-9

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