Differential Diagnosis

The PCP should be distinguished from secondary cutaneous plasmacytoma in MM, secondary skin involvement by extramedullary plasmacytomas (EMP) located elsewhere in mucosae or soft tissue, secondary skin involvement in Waldenstrom macro-globulinemia (WM), other primary B-cell lymphomas, and a variety of infectious diseases with prominent plasma cell infiltration (e.g., syphilis, borreliosis). In addition, some other inflammatory dermatoses involving the head and neck region are apt to show plasma cell-rich infiltrates-- a phenomenon called circumorificial plasmacytosis. They can usually be identified by the polyclonal nature of the infiltrate (immunohisto-chemistry), identification of the causative agent, clinical features and suggestive history.

Specific involvement of the skin in MM patients occurs in 2% of cases. Differentiation between PCP and specific cutaneous involvement in MM can only be made after additional clinical and laboratory investigations. The cutaneous clinical and histopathological features of PCP and MM are identical. Bone marrow examination, skeletal X-ray, peripheral blood and urine investigations are obligatory during the work-up of a patient with skin lesions consistent with plasmacytoma. Features indicative of MM include bone marrow plasmacytosis of >10%, osteolytic lesions, and detection of a plasma or urine paraprotein.

In the distinction of PCP from skin involvement in WM, clues to the diagnosis of WM include serum monoclonal IgM (>3 gm/dL) and consequent clinical findings (hyperviscosity symptoms, coagulopathies, neuropathies), and bone marrow infiltration by abnormal small to medium-sized lymphocytes showing plasmacytoid features expressing CD20 antigen.

Curing Eczema Naturally

Curing Eczema Naturally

Do You Suffer From the Itching, Redness and Scaling of Chronic Eczema? If so you are not ALONE! It strikes men and women young and old! It is not just

Get My Free Ebook


Post a comment