Recurrent Cutaneous Manifestation in Multiple Myeloma

Area of Science:

• Hematology
• Dermatology
• Oncology

Background:

• Cutaneous involvement in multiple myeloma (MM) is infrequent and often associated with aggressive disease subtypes.
• Clinical presentation of skin lesions in MM is typically non-specific and can be challenging to diagnose.
• Lower extremity involvement is particularly rare in the spectrum of MM cutaneous manifestations.

Observation:

• A unique case of a patient with refractory immunoglobulin G lambda MM is presented.
• The patient developed a lower leg recurrence while undergoing systemic therapy.
• The initial skin lesion mimicked squamous cell carcinoma, presenting a diagnostic dilemma.

Findings:

• Histopathological and immunohistochemical evaluation confirmed cutaneous involvement by MM.
• The recurrence occurred in the lower leg, an uncommon site for MM skin manifestation.
• The diagnosis was challenging due to the lesion's resemblance to squamous cell carcinoma.

Implications:

• This case underscores the necessity of a high index of suspicion for cutaneous MM in patients presenting with new skin lesions.
• Early and accurate diagnosis of cutaneous MM is critical for timely and appropriate therapeutic management.
• Recognizing diverse presentations of MM skin involvement can improve patient outcomes.