Hypocomplementemic paraneoplastic vasculitis: a rare case of B-cell malignancy

Area of Science:

• Dermatology
• Rheumatology
• Hematology

Background:

• Pemphigus foliaceus (PF) is a rare autoimmune blistering disease.
• Hypocomplementemic urticarial vasculitis (HUV) is associated with systemic involvement and malignancy risk.
• Atypical HUV presentations can occur without classic urticarial lesions.

Purpose of the Study:

• To report a rare case of atypical HUV syndrome in a patient with a long history of PF.
• To emphasize the association between hypocomplementemia, thrombocytopenia, and hematologic malignancy.
• To highlight the importance of considering paraneoplastic processes in autoimmune diseases with cutaneous vasculitic lesions.

Main Methods:

• Case report of a 55-year-old female with a 24-year history of PF.
• Clinical examination revealing an erythematous-violaceous, edematous lesion without urticaria.
• Laboratory evaluation including complement levels, complete blood count, and ANA.
• Systemic examination, hematology consultation, and genetic testing.

Main Results:

• The patient presented with atypical HUV syndrome characterized by hypocomplementemia and thrombocytopenia.
• A CD5-negative, CD19-positive B-cell lymphoproliferative disorder was diagnosed.
• Hepatomegaly was noted on systemic examination.
• Genetic testing excluded hereditary cancer mutations.

Conclusions:

• Atypical HUV presentations without urticaria require thorough evaluation for underlying hematologic malignancies.
• Hypocomplementemia and thrombocytopenia can be indicators of paraneoplastic syndromes in patients with autoimmune backgrounds.
• Prompt diagnosis and management of associated hematologic malignancies are essential.