Necrobiotic xanthogranuloma (nxg) - a cutaneous and systemic manifestation of a lymphoplasmaproliferative disorder

NXG is a chronic, progressive, inflammatory xanthomatous process involving the dermis and subcutaneous tissues. Extracutaneous involvement has been identified in the heart, lungs, larynx, genitourinary tract, and muscle. A monocionai protein is identified in nearly all patients and this usually represents a monoclonal gammopathy of undetermined significance (MGUS). Four diagnostic features are present in most cases; 1 ) indurated xanthomatous red to violaceous papules, nodules or plaques that may ulcerate; 2) palisading xanthogranulomas with Toulon and foreign body giant cells, necrobiosis, lymphoid infiltrate, and cholesterol clefts; 3) variable presence of elevated ESR, +ANA, low complement, and cryoglobulins; 4) M-protein, usually IgG. 13 cases of NXG were diagnosed at Mayo Clinic Scottsdale between 1987 and 1999. Their diagnostic features and systemic diseases were tabulated and included the following: Ages: 17-81 ; Sex: 8M, 5F; Duration: 1 -20 yrs (mean 6yrs); Cutaneous findings: NXG lesions -extremities(S), periorbital(7), trunk(5); plane xanthoma(2); cold urticaria(3); Extracutaneous findings: splenomegaly(3), hepatomegaly(l), adenopathy(2), uveitis(2), sinus NXG(1 ), pelvic wall NXG( 1 ), cardiac NXG( 1); Laboratory findings: elevated ESR(8/10), +ANA(7/13), +RF(4/13), cryoglobulins(2/J3), low CH50(5/12), low C4(6/l1), elevated cholesterol(7/12), elevated triglyceride(3/12), leukopenia(6/13), thrombocytopenia(2/13), anemia(5/13),pancytopenia(l/13),M-protein(1]/13)(IgGK8, IgGX 2, IgGK and Xl), B-J proteinuria (1). 12/13 patients had evidence of a lymphoplasmaproliferative disorder: MGUS(7), small lymphocytic lymphoma(2), Hodgkin's disease(l), B cell CLL(l), plasmacytoma of the cecum(l). No patient had myeloma or amyloidosis. Patients with bone marrow plasmacytosis had low plasma cell labeling indices. Only one patient has no identifiable lymphoplasmaproliferative disorder over 9 years of observation. NXG is most often associated with MGUS, but overt malignancy was found in 30% of our patients. Even in the absence of a M-protein, NXG may be a manifestation of an underlying lymphoplasmaproliferative disease warranting a detailed evaluation of all patients.