Unusual sequence of immunoglobulin L-chain rearrangements in a gamma heavy chain disease patient

Gamma heavy-chain disease: defining the spectrum of associated lymphoproliferative disorders through analysis of 13 cases

Gamma heavy-chain disease (gHCD) is defined as a lymphoplasmacytic neoplasm that produces an abnormally truncated immunoglobulin gamma heavy-chain protein that lacks associated light chains. There is scant information in the literature regarding the morphologic findings in this rare disorder, but cases have often been reported to resemble lymphoplasmacytic lymphoma (LPL). To clarify the spectrum of lymphoproliferative disorders that may be associated with gHCD, this study reports the clinical, morphologic, and phenotypic findings in 13 cases of gHCD involving lymph nodes (n=7), spleen (n=2), bone marrow (n=8), or other extranodal tissue biopsies (n=3). Clinically, patients showed a female predominance (85%) with frequent occurrence of autoimmune disease (69%). Histologically, 8 cases (61%) contained a morphologically similar neoplasm of small lymphocytes, plasmacytoid lymphocytes, and plasma cells that was difficult to classify with certainty, whereas the remaining 5 cases (39%) showed the typical features of one of several other well-defined entities in the 2008 WHO classification. This report demonstrates that gHCD is associated with a variety of underlying lymphoproliferative disorders but most often shows features that overlap with cases previously reported as "vaguely nodular, polymorphous" LPL. These findings also provide practical guidance for the routine evaluation of small B-cell neoplasms with plasmacytic differentiation that could represent a heavy-chain disease and give suggestions for an improved approach to the WHO classification of gHCD.

Gamma-heavy chain disease: review of 23 cases

We report the cases of 23 patients with gamma-heavy chain disease seen at our institution (8 patients previously reported, 15 new patients). There were 15 women and 8 men; the median age at diagnosis was 68 years (range, 42-87 yr). Sixteen patients had an associated lymphoplasma cell proliferative disorder, 3 had a lymphoplasma cell proliferative disorder and an autoimmune disorder, another 3 had an autoimmune disorder only, and 1 had no underlying disease. The lymphoplasma cell proliferative disorder was disseminated in 10 patients and localized in 6. Patients with localized lymphoplasma cell proliferative disorder included 3 with plasmacytoma (1 tongue, 1 submandibular area, and 1 thyroid), 2 with lymphoplasma cell proliferative disorder involving the bone marrow only, and 1 with amyloid of the skin. At the time of diagnosis, lymphadenopathy was present in 8 patients, splenomegaly in 7, and hepatomegaly in 1. A monoclonal spike on serum protein electrophoresis was documented in 19 patients. gamma-Heavy chain was documented by immunofixation in the serum of all patients; 2 had an additional immunoglobulin M-lambda. gamma-Heavy chain was present in the urine in 19 of 22 patients. Sixteen patients were treated for lymphoplasma cell proliferative disorder or autoimmune disorder (14 with chemotherapy, 1 splenectomy, and 1 thyroidectomy followed by radiation therapy). For 5 patients, treatment was not felt to be necessary; 2 patients were thought to be too sick for treatment. Of the 16 patients treated, 6 had a complete clinical response (in 2, gamma-heavy chain disappeared; in 2, gamma-heavy chain persisted; and for 2, no serologic follow-up was available); in 10 patients, clinical disease persisted (in 3, gamma-heavy chain disappeared; in 6, it persisted; and for 1, no serologic follow-up was available). Of 7 patients not treated, 2 died within 5 months; 1 died after 15 months; 2 had no clinical disease at latest follow-up, although gamma-heavy chain persisted; and 2 had no change in clinical and serologic status. The median duration of follow-up was 33 months (range, 1-261 mo). Median survival was 7.4 years.