Orbital indeterminate cell histiocytosis.

Area of Science:

• Ophthalmology
• Pediatric Oncology
• Dermatology

Background:

• Indeterminate cell histiocytosis (ICH) is a rare histiocytic disorder.
• Orbital involvement in ICH is uncommon, especially as an isolated presentation.
• Early diagnosis and management are crucial for favorable outcomes.

Purpose of the Study:

• To report a rare case of isolated orbital indeterminate cell histiocytosis in a pediatric patient.
• To highlight the clinical presentation, diagnostic workup, and treatment of this rare condition.
• To emphasize the importance of considering ICH in the differential diagnosis of pediatric orbital masses.

Main Methods:

• A case study of an 8-year-old female with a 3-month history of left upper eyelid fullness and edema.
• Clinical examination, orbital imaging (MRI), and incisional biopsy with histopathology and immunohistochemistry.
• Treatment with oral hydroxyurea and follow-up assessment of lesion progression.

Main Results:

• Histopathology confirmed indeterminate cell histiocytosis with positive CD68 and CD163 staining.
• The orbital mass showed no change in size after 3 months of hydroxyurea treatment.
• No systemic involvement or associated dermatologic findings were observed.

Conclusions:

• Isolated orbital indeterminate cell histiocytosis is a rare entity in children.
• Orbital imaging and histopathology are key for diagnosis.
• Hydroxyurea may be an effective treatment option for localized orbital ICH, warranting further investigation.