Ewing sarcoma was first described in 1921 by James Ewing. They arise from mesenchymal progenitor cells and are part of a spectrum of neoplastic diseases, known as Ewing’s sarcoma family of tumors (ESFT) [1]. Ewing's sarcoma family of tumors (ESFT) represents a family of morphologically similar small round-cell neoplasms, including classic Ewing's sarcoma (ES) of the bone next to extraskeletal ES, small-cell tumor of the thoracopulmonary region (Askin tumor) and soft-tissue-based primitive neuroectodermal tumors (PNETs). ESFT are characterized by reciprocal translocation between chromosome 11 & 22, t (11; 22), and are usually seen at osseous sites, both axial and appendicular. Extra- osseous presentation is uncommon.

Ewing sarcoma is the second most common childhood primary bone cancer, though a substantial proportion of these tumors arise from extraskeletal sites [2]. Ewing sarcoma usually arises in bone and is associated with soft tissue extension in 90% of cases. EES arises in the soft tissues of the trunk or extremities. Although it is a soft tissue primary tumor, it can cause changes in the cortex of the adjacent bone [3-5]. The most common sites are chest wall, paravertebral region, retroperitoneal space, lower extremities, and gluteal region. However, few cases have been reported in the kidney, breast, gastrointestinal tract, prostate, endometrium, the adrenal glands, brain, and lungs [6]. The head and neck region is an unusual primary site for this type of tumor.

ES also occurs as a primary soft tissue neoplasm without involvement of bone [7]. Ewing sarcoma (ES) is a poorly differentiated, highly malignant, round cell tumor without cellular or structural differentiation [8]. Histological assessment shows that these (EES) tumors are composed of sheets of small round cells with hyperchromatic nuclei, and scanty cytoplasm.

Immunohistochemically, a number of markers have been used, of which MIC2 (CD99) is particularly useful in eliciting membranous positive staining of tumor cells [9]. Here, authors present a case of extraskeletal Ewing sarcoma presenting in right supraclavicular region in a 23 years female with recurrence of same tumor at same site without bone involvement or metastases from any other place with 16 years of survival.

Pseudorosette formation was noted in the tumor (Fig. 4). Mitotic count was 1-2/10 HPF and necrosis was not seen. Lymphovascular invasion not seen. Base was involved by tumor.

Figure 2: Photomicrograph showing partially encapsulated tumor mass and composed of sheets of monomorphic, round cells with large hyperchromatic nuclei and scanty cytoplasm. (H&E, 5X).

Figure 3: Photomicrograph showing tumor mass composed of sheets of monomorphic, round cells with large hyperchromatic nuclei and scanty cytoplasm. (H&E, 40X)

Figure 4: Photomicrograph showing Pseudorosette formation. (H&E, 10X)

The diagnosis and treatment of soft tissue small cell sarcomas continues to be a challenge to the pathologist and the medical and surgical oncologist. Malignant small round cell tumor are characterized by small, round, relatively undifferentiated cells. They include Ewing’s sarcoma, peripheral neuroectodermal tumor, rhabdomyosarcoma, synovial sarcoma, Non–Hodgkin’s lymphoma, neuroblastoma, hepatoblastoma and nephroblastoma.

On histopathological examination these tumors appear similar due to morphological similarities. Thus, for further typing of tumor one should do special stains, immunohistochemistry, fluorescence in situ hybri-dization or electron microscopic examination. Once the specific diagnosis is made then appropriate treatment and management can be approached. It also helps to assess the prognosis of the patient.

Allam et al has reported a male to female ratio of 2.4:1 in a series of 24 patients [10].

Approximately 80% of patients are diagnosed with Ewing sarcoma at a younger age of less than 20 years. A total of 50-60% patients are diagnosed during their second decades [11].

Tefft et al first described EES in 1969 to be histologically similar to primary Ewing’s sarcoma of bone [3].

Here a female patient who was diagnosed at the age of 12 years with small round cell tumor. Radiological investigation like MRI was also suggestive of sarcoma with no bone involvement. MRI is the most sensitive test available for the evaluation of the soft tissue extent of the tumor [12].

In this present case, tumor recurred after 16 years at the same site without any complication. Surgical removal was done as it is the treatment of choice [13] for EES, followed by adjunctive chemotherapy and radiotherapy.

Around 75% patients present with rapidly growing painless mass, 30% patients exhibiting distant metastasis at the time of diagnosis. Clinically, patients with EES usually present with a painless, rapidly growing mass but tumors arising elsewhere may be painful.

Our patient presented with a slow growing mass in the right side of neck.

The remaining two patients died within 6 months of surgery. One patient died from brain metastases 5 months after surgery and one patient died from treatment toxicity [19].

In this case diagnosis of Ewing sarcoma was made on immunohistochemical staining as described above. Inspite of recurrence & huge size of tumor, patient was otherwise asymptomatic. As Ewing sarcoma has an aggressive course especially after recurrence, ours is a rare case of more than 16 years survival inspite of recurrence without any complication.

Primary cervical EES is rare. No specific treatment guidelines have been established for EES. Consequently, treatment depends on patient’s age, progression of tumor & its complications. Multimo-dality such as X-ray, MRI, CT scan and FNAC were used for diagnosis & the definitive diagnosis was made on histopathology & IHC (Immunohistochemistry) examination. IHC is mandatory for diagnosis of soft tissue Ewing’s sarcoma in younger age group patients. Regular follow up of such patients is essential for timely detection & complete treatment of recurrent tumors. The aim should be to improve or preserve the quality of life and long-term survival of patients.

Dr. Vikas D. Pathak and Dr. Gauri Metkar: Histopathology reporting, follow up of case and manuscript preparation. Dr. Smita Bhide and Dr. Sneha Joshi: Guidance in manuscript preparation.