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Schwannomas are rare tumours arising from peripheral nerve sheath and are usually related to the spinal cord and spinal nerves. Contrast magnetic resonance imaging (MRI) usually helps in establishing a pre-operative diagnosis. Rarely, their manifestation may be surprisingly new. Here, a 44-year-old lady came to our clinic with a painless asymptomatic progressively enlarging swelling over her upper back. It was fluctuant, with absent neural signs and symptoms. MRI showed a benign, purely-cystic, superficial-intermuscular, extra-spinal swelling near the upper thoracic vertebrae. However, classical diagnostic signs of schwannoma were absent. Complete surgical excision was performed with smooth dissection through a well-defined plane between the lesion and surrounding muscles. A 6.5x5.0x2.5 cm oval lesion with a glistening whitish-grey capsule was excised, and the deep wound was reconstructed in multiple layers. Interestingly, it was not attached to any identifiable nerves. Histopathology showed typical hallmarks like Antoni A regions and Verocay bodies. Positive S-100 staining during immunohistochemistry established its diagnosis as schwannoma. The postoperative one-and-half-year follow-up period was uneventful. Cystic schwannomas can surprise and confuse clinicians by arising anywhere in the body and with atypical manifestations. Surgeons need to consider it in the differential diagnoses of any undiagnosed slowly-growing swelling, including purely-cystic ones and perform careful surgical dissection to avoid any inadvertent nerve damage.


Cystic schwannoma Extraspinal cyst Superficial intermuscular cyst Magnetic resonance imaging Surgical excision Case Report

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How to Cite
Saha, S. (2020). A rare presentation of superficial, inter-muscular, cystic, extra-spinal schwannoma over upper back . Neurologico Spinale Medico Chirurgico, 3(3), 103-106.


  1. Kim DH, Murovic JA, Tiel RL, et al. A series of 397 peripheral neural sheath tumors: 30-year experience at Louisiana State University Health Sciences Center. J Neurosurg. 2005;102(2):246-255. DOI:10.3171/jns.2005.102.2.0246
  2. Crist J, Hodge JR, Frick M, et al. Magnetic Resonance Imaging Appearance of Schwannomas from Head to Toe: A Pictorial Review. J Clin Imaging Sci. 2017;7:38. DOI:10.4103/jcis.JCIS_40_17
  3. Kransdorf MJ. Malignant soft-tissue tumors in a large referral population: distribution of diagnoses by age, sex, and location. AJR Am J Roentgenol. 1995;164(1):129-134. DOI:10.2214/ajr.164.1.7998525
  4. Montano N, D'Alessandris QG, D'Ercole M, et al. Tumors of the peripheral nervous system: analysis of prognostic factors in a series with long-term follow-up and review of the literature. J Neurosurg. 2016;125(2):363-371. DOI:10.3171/2015.6.JNS15596
  5. MacCollin M, Chiocca EA, Evans DG, et al. Diagnostic criteria for schwannomatosis. Neurology. 2005;64(11):1838-1845. DOI:10.1212/01.WNL.0000163982.78900.AD
  6. Knight DM, Birch R, Pringle J. Benign solitary schwannomas: a review of 234 cases. J Bone Joint Surg Br. 2007;89(3):382-387. DOI:10.1302/0301-620X.89B3.18123
  7. Farschtschi SC, Mainka T, Glatzel M, et al. C-Fiber Loss as a Possible Cause of Neuropathic Pain in Schwannomatosis. Int J Mol Sci. 2020;21(10):3569. DOI:10.3390/ijms21103569
  8. Zhang Z, Deng L, Ding L, et al. MR imaging differentiation of malignant soft tissue tumors from peripheral schwannomas with large size and heterogeneous signal intensity. Eur J Radiol. 2015;84(5):940-946. DOI:10.1016/j.ejrad.2015.02.003
  9. Rodriguez FJ, Folpe AL, Giannini C, et al. Pathology of peripheral nerve sheath tumors: diagnostic overview and update on selected diagnostic problems. Acta Neuropathol. 2012; 123(3): 295-319. DOI:10.1007/s00401-012-0954-z
  10. Louis DN, Ohgaki H, Wiestler OD, et al. editors. WHO Classification of Tumours of the Central Nervous System. 4th ed., Revised. Lyon: International Agency for Research Centre; 2016.