• Characterized by widespread skeletal & extra – skeletal lesions & chronic clinical course.
• Occurs primarily in early life, before the age of 5; more common in boys & girls.
• Most cases reported from Western literature, authentic cases from India are few.

Clinical features:-

• Classic triad of :-

1. Single or multiple areas of ‘punched out’ bone destruction in skull
2. Unilateral or bilateral exophthalmos
3. Diabetes insipidus with or without other manifestations of dyspituitarism

• Involvement of facial bones frequently associated with soft tissue swelling & tenderness; causes facial symmetry.
• Classically involves the flat bones of the skull, ribs, pelvis, and scapula
• Diabetes insipidus affects 5 to 50% of patients.
• Skin involvement in the form of erythematous scaly rash or papular or nodular lesions which is seen in only 30% of patients.
• Poor sexual development and retarted growth is another feature.
• Vision loss or strabismus caused by optic nerve or orbital muscle involvement occurs rarely.
• Chronic otitis media and otitis externa due to involvement of the mastoid and petrous portions of the temporal bone with partial obstruction of the auditory canal are fairly common

Oral manifestations:-

• Earliest signs of the disease; may be present in 5 – 75% of cases.
• Often non specific; sore mouth, halitosis, gingivitis, ulcerations, loose teeth, suppuration, failure of healing of extraction sockets
• Loss of supporting alveolar bone mimicking advanced periodontal disease is characteristic.

Radiological features:-

• Skull lesions sharply outlined; jaw lesions may be diffuse.
• Jaw lesions manifested as bone destruction with tooth displacement.
• Panoramic may show remarkable atrophy of the alveolar ridge and severe parodontitis.
• Remaining teeth abnormally sited in an extra alveolar position

Histological features:-

• Manifesting in four stages during progression of characteristic lesion
• Proliferative histiocytic phase with accumulation of collections of eosinophilic leukocytes scattered throughout sheets of histiocytes.
• Vascular – granulomatous phase with persistence of histiocytes & eosinophils, sometimes with aggregation of lipid laden (cholesterol) macrophages.
• Diffuse xanthomatous phase with abundance of ‘foam cells’
• Fibrous healing phase.
• Infiltration with CD1 positive histiocytes disclosing intracytoplasmic Birbek granules at the electron microscopic examination .
• Histological diagnosis is based on the presence of a histiocytic infiltrate in the upper and middle dermis.
• The optical microscope examination reveals in the papillary dermis an important oedema, large cells with an indented nucleus and abundant eosinophilic cytoplasm
• Histochemical colouring, showing positiveness for S-100 protein, the presence of CD1, CD4 and HLA-DR surface antigens confirm the diagnosis

Treatment & prognosis:-

• Therapy of the Hand-Schuller-Christian disease varies according to the age of the patient, the severity and extent of the clinical picture.
• Approximately half of the patients undergo spontaneous remission over a period of years.
• Treatment of choice is curettage or excision of lesions.
• Inaccessible lesions may be irradiated.
• Some patients may benefit from chemo – therapeutic drugs like Prednisone, Vinblastine & Cyclophosphamide.

Reference:

1.Faculty notes

2.Google