Eosinophilic Granuloma

By admin On Jan 18, 2024

Ovid: 5-Minute Orthopaedic Consult

Editors: Frassica, Frank J.; Sponseller, Paul D.; Wilckens, John H.

Title: 5-Minute Orthopaedic Consult, 2nd Edition

> Table of Contents > Eosinophilic Granuloma

Eosinophilic Granuloma

Frank J. Frassica MD

Basics

Description

EOG is the bony, and most common, manifestation of a group of nonneoplastic disorders known as “LCH.”
3 basic scenarios occur:
- Solitary site bone disease
- Multiple bone lesions without visceral disease
- Multiple bone lesions and visceral disease
EOG commonly affects the skull, ribs, pelvis, spine, diaphysis of long bones, and mandible, but any bone may be involved.
It more commonly affects a single bone rather than multiple bones.
LCH:
- Spectrum of disease involvement rather than separate specific entries
- In the past, divided into 3 separate conditions:
  - EOG: Single intramedullary site of bone disease
  - Hand-Schüller Christian disease: Multiple
    sites of bone disease and visceral disease (skin, lymph nodes, liver,
    spleen, etc.); the classic triad (Christian triad) (uncommon by itself)
    involves lytic skull disease, exophthalmos, and diabetes insipidus.
- Letter-Siwe disease: Fulminant condition
  in young children (<2 years old) with widespread involvement that
  often results in death (lymphadenopathy, hepatosplenomegaly, and
  extensive pulmonary disease)
Synonyms: Histiocytosis X; Langerhans cell histiocytosis; Reticuloendotheliosis

Epidemiology

Incidence

Rare

Prevalence

Usually seen in patients <30 years old, with a peak incidence at age 5–10 years (1)
Male:Female ratio of 2:1 (1)

Etiology

The cause of the accumulation of abnormal metabolic products in the reticuloendothelial cells is unknown.
An inflammatory response occurs around these cells and produces the lytic destruction of bone.

Diagnosis

3 diagnostic criteria for LCH of the spine (2)
Percutaneous needle biopsy is a very effective method of establishing the diagnosis (3).

Signs and Symptoms

Local pain
Swelling, tenderness
Warmth at the site of involvement
Occasional fever

Physical Exam

The skull and skeleton should be palpated for areas of tenderness.
Note the position of the eyes within the orbit.
The spine should be percussed for tenderness.
The patient’s gait should be observed for the presence of a limp.

Tests

Lab

Elevated ESR
Peripheral eosinophilia

Imaging

Radiography:
- Plain radiographs show sharply circumscribed, “punched-out” lytic lesions.
- As the lesion heals, a thick rim of reactive bone forms around the periphery.
- The cortex may be destroyed with endosteal scalloping, periosteal reaction, and expansion of the bone.
- If the cortex is destroyed unevenly (EOG
  attacks cortex from within the canal, but 1 side of the cortex may be
  more involved than the other), a “hole within a hole” appearance ensues.
- In the vertebra, the body may collapse to a slender sclerotic wafer of bone called vertebra plana.
- In the mandible and maxilla, the lytic lesion appears as a “floating tooth.”
Bone scanning usually is not recommended because the lesions may not be “hot” on bone scan.

Pathological Findings

Sheets of “foamy” (lipid-filled) histiocytes:
- Coffee-bean-shaped nucleus
- Crisp nuclear membrane
- Abundant pale eosinophilic cytoplasm
- Staining with S-100 and Cd1a stains (1)
Inflammatory cells found around these histiocytes:
- Predominantly eosinophils, but also a few lymphocytes, neutrophils, and giant cells

P.119

Differential Diagnosis

Ewing sarcoma
Lymphoma
Osteomyelitis
EOG appropriately is called the “great imitator,” because it may mimic infection or neoplasm.

Treatment

General Measures

Most lesions are self-limiting and resolve spontaneously.
Options include:
- Observation
- Curettage and bone grafting
- Injection with steroids
If a pathologic fracture is impending, or the articular surface is in danger, curettage and bone grafting are necessary.
Biopsy often is necessary except for characteristic spine lesions.

Medication

Methylprednisolone acetate injected into the lesion is effective in >90% of patients, with excellent bone healing (3).
For patients with systemic disease with
constitutional symptoms, chemotherapy with methylprednisolone,
methotrexate, doxorubicin (Adriamycin), and other agents is indicated.
Vertebra plana usually heals itself, and vertebral body height is restored with time.

Surgery

Surgery is unnecessary in most cases.
However, curettage and bone grafting with
or without internal fixation are indicated if nonoperative measures
fail and pathologic fracture seems imminent.

Follow-up

Complications

Pathologic fractures may occur.
- Usually heal well with closed or operative treatment

Patient Monitoring

Observation with plain radiographs is indicated if the
diagnosis is clear-cut and the patient has no impending fracture, until
lesions resolve (usually 6 months).

References

1. Dorfman HD, Czerniak B. Immunohematopoietic tumors. In: Bone Tumors. St. Louis: Mosby, 1998: 664–728.

2. Garg S, Mehta S, Dormans JP. Langerhans cell histiocytosis of the spine in children. Long-term follow-up. J Bone Joint Surg 2004;86A: 1740–1750.

3. Yasko
AW, Fanning CV, Ayala AG, et al. Percutaneous techniques for the
diagnosis and treatment of localized Langerhans-cell histiocytosis
(eosinophilic granuloma of bone). J Bone Joint Surg 1998;80A:219–228.

Additional Reading

McCarthy EF, Frassica FJ. Skeletal manifestations of systemic disease. In: Pathology of Bone and Joint Disorders: With Clinical and Radiographic Correlation. Philadelphia: WB Saunders, 1998:119–133.

Miscellaneous

Codes

ICD9-CM

277.8 EOG

Patient Teaching

Reassure the patient and family about the self-limiting nature of most lesions.
Make sure that the child and parents understand the need for close follow-up care.
Make sure disease progression is not occurring.
Ensure that this is not the initial presentation of widespread disease.

Activity

No restrictions are placed on activity unless the patient has an impending pathologic fracture.

FAQ

Q: Is EOG or LCH a malignant condition?

A: No. It is a self-limited inflammatory process.

Q: What is the prognosis when a single bone is involved?

A: The prognosis is excellent.

Q: Do patients with complete vertebral collapse need surgery?

A:
Patients with complete vertebral collapse can be treated
symptomatically, and only ~10% of patients with LCH of the spine need
reconstructive surgery at long-term follow-up.