Multicentric reticulohistiocytosis: A diagnostic challenge

Area of Science:

• Dermatology
• Rheumatology
• Pathology

Background:

• Multicentric reticulohistiocytosis (MRH) is a rare non-Langerhans cell histiocytosis.
• It is characterized by skin lesions and arthritis, involving skin, mucosa, synovium, and internal organs.

Observation:

• A 61-year-old male presented with a 6-year history of distal finger swellings.
• Notably, this patient exhibited no joint involvement, an uncommon presentation for MRH.

Findings:

• Histopathological examination revealed sheets of histiocytes and multinucleate giant cells with characteristic ground glass eosinophilic cytoplasm.
• Diagnosis of multicentric reticulohistiocytosis was confirmed based on these typical features.

Implications:

• This case underscores the importance of considering MRH even in the absence of arthritis.
• Reporting rare presentations aids in understanding the spectrum of this low-incidence disease, with only about 300 cases reported historically.