Paraneoplastic pemphigus presenting with a single oral lesion

Area of Science:

• Immunodermatology
• Oncology
• Oral Medicine

Background:

• Paraneoplastic pemphigus (PNP) is an autoimmune blistering disease often associated with hematological malignancies.
• Typical PNP presentation includes severe oral ulcerations, skin lesions, and ocular involvement.

Observation:

• A case of PNP is presented in a patient with no prior diagnosis of neoplasia.
• The patient exhibited a unique oral ulcer with specific histological and immunofluorescence findings suggestive of PNP.
• Initial presentation lacked typical widespread mucocutaneous lesions.

Findings:

• Histopathology revealed acantholysis of the basal epithelial layer, necrotic keratinocytes, and regenerative hyperplasia.
• Direct immunofluorescence showed intercellular and basement membrane deposition of IgG, fibrinogen, and C3.
• Indirect immunofluorescence demonstrated characteristic fluorescence patterns.
• Subsequent diagnosis of monoclonal gammopathy of undetermined significance (MGUS) was confirmed.

Implications:

• This case expands the clinical spectrum of PNP presentation, emphasizing oral lesions as an early sign.
• It underscores the importance of considering PNP in patients with unexplained oral ulcerations, even without a known malignancy.
• The association with MGUS highlights the link between autoimmune disorders and premalignant plasma cell conditions.