April 11, 2024

Ewing Sarcoma is the third most common primary tumor of bone and the second most common malignant bone tumor of late childhood and early adulthood (1 % of childhood cancers).

Ewing Sarcoma belongs to the small, round, blue-cell tumors that are thought to arise from primitive mesenchymal cells.

Ewing Sarcoma
Ewing Sarcoma

EWS gene on chromosome 22

Reciprocal translocation on FL11 gene on chromosome 11t (11,22)

Primitive Neuroectodermal tumor (PNET) of bone tumor

Male: Female::1.4:1

For the First two decades

Site: Most frequent site of involvement

[Pelvis > Long bone > Ribs > Vertebral Column]

Clinical Features

Most common clinical symptoms: Pain and swelling

10 % of patients: Pathological fractures

Tumor is confused with infection

MRI is excellent at describing lesions: Describing in the marrow

X-Ray shows typical Onion Peel appearances

Trisomy-8, CD 99 (+), PAS (+), MIC 2 (+), T (11,22)

Laboratory Investigations

Anemia, Leukocytosis, Increase LDH (Have prognostic significance)

Staging workup: Chest CT

The lungs are the most common site for metastasis

Bone marrow biopsy: Mandatory ( to look for disseminated disease)

Approximately: 25 % of patients present with metastasis

Pathology

Meta diaphysis and diaphysis predominantly

Extensive invasion of medullary bone, destruction of endosteum and cortex

Extend for a greater distance in the medulla (than is apparent n X-rays)

Grayish-white tumors; Encapsulated by fibrous tissues

Microscopic Examinations

Monomorphic cells, small, round, blue cells

Rosette formulation: PNET

Periodic acid Schiff ( PAS is positive)

CD 99 (MIC 2), an immunohistochemistry marker (Positive) for Ewing sarcoma

EWS translocation detection (by PCR or FISH) is mandatory in clinical and pathological presentation is unusual and histological diagnosis is doubtful.

Ewing Sarcoma
Ewing Sarcoma

Treatment

Multidisciplinary Actions

Multiagent Chemotherapy

Surgery

Radiation

See also: Musculoskeletal Malignancy: Management

6 cycles of initial chemotherapy

10-12 months duration

In 3 weeks of interval

Myeloablative Therapy and Stem cell transplantation: Uncertain values

Surgery + Radiotherapy are the Principle mode of treatment

Chemotherapeutic Agents

  • Doxorubicin
  • Cyclophosphamide
  • Ifosfamide
  • Vincristine
  • Etoposide
  • Dactinomycin

See also: Osteosarcoma

See also: Limb Salvage Surgery: Principles

Previous Post

Next Post