Isolated rheumatoid nodules: a diagnostic dilemma

Area of Science:

• Dermatology
• Rheumatology
• Pathology

Background:

• A 27-year-old male presented with a long-standing history of multiple, non-painful soft tissue masses.
• These masses were located on metacarpals, elbows, wrist, and knees, present since childhood.
• Physical examination revealed firm, nonmobile, nodular growths on extensor surfaces.

Purpose of the Study:

• To present a case of multiple soft tissue masses with a differential diagnosis including subcutaneous granuloma annulare (SGA) and rheumatoid nodules.
• To emphasize the diagnostic challenges and the importance of biopsy in differentiating these conditions.
• To highlight potential complications and the need for diligent follow-up.

Main Methods:

• Clinical presentation and physical examination findings were documented.
• Laboratory investigations included rheumatoid factor and antinuclear antibody (ANA) screening.
• Joint radiographs were performed.
• Differential diagnoses were considered, including SGA, seronegative rheumatoid nodule, and calcinosis cutis.

Main Results:

• Laboratory studies and joint radiographs were unremarkable.
• The differential diagnosis was narrowed to SGA and rheumatoid nodule.
• Biopsy was identified as the definitive method for distinguishing between SGA and rheumatoid nodules.

Conclusions:

• Accurate diagnosis of soft tissue masses requires consideration of various differentials.
• Histopathological examination (biopsy) is essential for distinguishing between conditions like SGA and rheumatoid nodules.
• Awareness of potential complications and the necessity for thorough patient follow-up are critical.