Cytodiagnosis of Primary Ewing Sarcoma of the Skull: Diagnostic Clues and Difficulties

  • Renu Sukumaran Division of Pathology, Regional Cancer Centre, Thiruvananthapuram, Kerala, India
  • Nileena Nayak Division of Pathology, Regional Cancer Centre, Thiruvananthapuram, Kerala, India
Keywords: Ewing sarcoma, Fine needle aspiration cytology, scalp

Abstract

Ewing sarcoma is a rare primary neoplasm of bone representing approximately 6-8% of all malignant bone tumours. Because of its aggressive clinical behaviour and rapid dissemination to other sites, an early accurate diagnosis is of utmost importance. It shares morphological features with other round cell tumors. Common differentials include lymphoblastic lymphoma, neuroblastoma, rhabdomyosarcoma and neuroendocrine tumours. Due to the morphological overlap, critical evaluation of the cellular details is essential. Fine needle aspiration cytology becomes a successful diagnostic tool when the subtle diagnostic clues and difficulties are considered during diagnosis. Judicious use of ancillary techniques will also aid in arriving at an accurate diagnosis. We present the case of a seven-year-old boy who presented with painful swelling of the scalp. Aspiration smears were cellular and showed atypical small round cells. Evaluation of morphological details along with special stains and immunohistochemistry in cell block preparation aided in rendering a diagnosis of Ewing sarcoma. The awareness of overlapping features in clinical presentation, morphology and immunohistochemical findings will help to arrive in the proper diagnosis. Early diagnosis on cytology samples can help in timely initiation of treatment, thus improve prognosis.

References

Agrawal A, Dulani R, Mahadevan A, Vagaha S J, Vagha J, Shankar S K. Primary Ewings sarcoma of the frontal bone with intracranial extension. J Can Res Ther. 2009; 5:208-9.

Salunke PS, Gupta K, Malik V, Kumar N, Henke LE, Cai C, et al. Primary Ewing′s sarcoma of cranial bones: Analysis of ten patients. Acta Neurochir (Wien). 2011; 153:1477-85.

Desai K, Goel A, Nadkarni TD. Primary petrous bone Ewing's sarcoma. Br J Neurosurg . 2000; 14:143–5

Erol FS, Ozveren MF, Ozercan IH, et al. Primary Ewing's sarcoma of the occipital bone—case report. Neurol Med Chir. 2001 ;41:206–9.

Parija T, Shirley S, Uma S, Rajalekshmy KR, Ayyappan S, Rajkumar T. Type 1 (11;22) (q24: q12) translocation is common in Ewing sarcoma/peripheral neuroectodermal tumour in south Indian patients. J Biosci. 2005; 30:371-76.

Halliday BE, Slagel DD, Elsheikh TE, Silverman JF. Diagnostic utility of MIC-2 immunocytochemical staining in the differential diagnosis of small blue cell tumors. Diagn Cytopathol 1998;19(6):410-6.

Rajwanshi A. Cytology of soft tissue tumors: Malignant small round cell tumors. J Cytol 2008; 25:89-92

Gu M, Antonescu CR, Guiter G, Huvos AG, Ladanvi M, Zakowski MF. Cytokeratin immunoreactivity in Ewings sarcoma: prevalence in 50 cases confirmed by molecular diagnostic studies. Am J Surg Pathol. 2000; 24:410-6.

Krishnamani K, Kumar TN, Gandhi LV, Raghunadharao D, Sadashivudu G, Megha U. Primary Ewing's sarcoma of the cranium: Case series and review of literature. J Can Res Ther. 2014; 10:377-80

van den Berg H, Heinen RC, van der Pal HJ, Merks JH. Extra-osseous Ewing sarcoma. Pediatr Hematol Oncol. 2009; 26:175-185.

Published
2021-05-10
Section
Case Report