Eosinophilic Granuloma

Summary
Description

Eosinophilic granuloma (EG) is a solitary, non-neoplastic proliferation of histiocytes. EG is part of a spectrum of Langerhan's cell histiocytosis, formerly known as histiocytosis X.

People and Age
The male to female ratio is two to one. It occurs most commonly in children aged 5 to 10 and is uncommon in blacks.
Symptoms and Presentation
EG is normally symptomatic. Local pain, swelling and tenderness are common and the ESR may be elevated.
Brief description of the xray
The radiologic appearance of EG is non-specific and differs by location.
Tumor Name
Eosinophilic Granuloma
Tumor Type
Tumors - unknown type
Benign or Malignant
Benign
Body region
located in multiple bones
Most Common Bones
skull
Complete Information on this Tumor
Introduction and Definition

Eosinophilic granuloma (EG) is a solitary, non-neoplastic proliferation of histiocytes. EG is a localized lesion in bone or lung. EG is part of a spectrum of Langerhan's cell histiocytosis, formerly known as histiocytosis X. EG is found in the skull, mandible, spine and long bones. Letterer-Siwe disease is a fulminant systemic disease that comprises 10% of Langerhan's cell histiocytosis, occurs in children under 3 years old and is rapidly fatal. Hand-Schuller-Christian disease (HSC) is a chronic disseminated form of Langerhan' s histiocytosis and occurs in older patients. The well known triad of HSC is diabetes insipidus, exopthalmos and skull lesions. EG can convert to systemic forms of the disease. It makes up 60-80% of all cases of Langerhan's cell histiocytosis.

Incidence and Demographics
The male to female ratio is two to one. It occurs most commonly in children aged 5 to 10 and is uncommon in blacks.
Symptoms and Presentation

EG is normally symptomatic. Local pain, swelling and tenderness are common and the ESR may be elevated.

X-Ray Appearance and Advanced Imaging Findings
The radiologic appearance of EG is non-specific and differs by location. The skull may have a lesion with sharp, punched out borders that is uneven across the inner and outer table causing a "beveled edge". Pelvic lesions are often poorly defined. Spine lesions are normally found in the vertebral body. EG is found in the diaphysis or metaphysis of long bones in the center of the medullary cavity. The lesion may cause endosteal scalloping or a periosteal reaction. Bone scan is not useful in defining EG. CT scan and MRI delineate the extent of the intramedullary and cortical penetration.
Differential Diagnosis
The radiologic differential includes Ewing's sarcoma, osteosarcoma, metastases and osteomyelitis.
Histopathology findings
On gross examination, EG is a soft, granular or gelatinous mass. It appears gray red to brown with flecks of yellow.
Under the microscope, EG consists of sheets of Langerhan's cells. These cells are derived from the mononuclear cell and dendritic line precursors and are found in the bone marrow. The cell is identifiable under the electron microscope as the Langerhan's cell has racket shaped cytoplasmic inclusion
bodies called Birbeck's granules. Also present in the lesion are varying amounts of lymphocytes, polymorphonuclear cells, eosinophils and giant cells. Early lesions have many Langerhan's cells and eosinophils. Older lesions have fewer cells and much fibrous tissue. The cause of EG is unknown and speculated to be either infection or immunological.
Treatment Options for this Tumor
Treatment of EG depends on the form of the disease. With localized disease, often a biopsy alone is enough to incite healing. Other treatment modalities of EG include curettage, excision, steroid injection, radiation and observation. ' . Chemotherapy is recommended for systemic disease.
Outcomes of Treatment and Prognosis
Often a biopsy alone is enough to incite healing.
Suggested Reading and Reference
' Mackenzie, WG and KS Morton, Eosinophilic Granuloma of Bone, The Canadian Journal of Surgery, 31(4):264-267, July, 1988.

Greis, PE and FM Hankin, Eosinophilic Cranuloma, Clinical Orthopaedics and Related Research, 257:204211, August, 1990.

Conway, WF and CW Hayes, Miscellaneous Lesions of Bone, Radiologic Clinics of North America, 31(2): 339-357, March, 1993.

Bulloughs, Peter. Orthopaedic Pathologv (third edition), Times Mirror International Publishers Limited, London, 1997. Huvos, Andrew. Bone Tumors: Diagnosis. Treatment and Prognosis, W.B. Saunders, Co., 1991.