Gamma heavy chain disease in man: independent structural abnormalities and reduced transcription of a functionally rearranged lambda L-chain gene result in the absence of L-chains

Gamma heavy chain disease in a patient with underlying lymphoplasmacytic lymphoma of the thyroid. Report of a case and comparison with other reported cases with thyroid involvement

BACKGROUND

Gamma heavy chain disease with underlying thyroid pathology is rare. There are 5 reported cases in the English literature, including the present case of an elderly female with γ heavy chain disease with underlying lymphoplasmacytic lymphoma of the thyroid who initially presented with long-standing goiter and chronic thyroiditis.

METHODS

The protein studies and histopathologic findings in her thyroid are described. Her case is compared with reported cases of γ heavy chain disease with thyroid involvement.

RESULTS

Initial impression on most cases was chronic thyroiditis; however pathology showed 3 cases with plasmacytoma and 2 with lymphoplasmacytic infiltrate. All were diagnosed and followed up using serum and urine electrophoresis.

CONCLUSION

Gamma heavy chain disease has a protean manifestation; however there appears to be a more uniform pattern of the disease when it is associated with the thyroid. The inclusion of protein studies in cases diagnosed with chronic thyroiditis by FNA may aid in establishing γ heavy chain disease with underlying thyroid involvement. In this case serum and urine electrophoresis, and immunofixation studies which are simple and affordable tests facilitated the hematologic workup and follow up.

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.

Immunoproliferative small intestinal disease (IPSID): a model for mature B-cell neoplasms

Immunoproliferative small intestinal disease (IPSID) was recently added to the growing list of infectious pathogen-associated human lymphomas. Molecular and immunohistochemical studies demonstrated an association with Campylobacter jejuni. IPSID is a variant of the B-cell lymphoma of mucosa-associated lymphoid tissue (MALT), which involves mainly the proximal small intestine resulting in malabsorption, diarrhea, and abdominal pain. Geographically, IPSID is most prevalent in the Middle East and Africa. IPSID lymphomas reveal excessive plasma cell differentiation and produce truncated alpha heavy chain proteins lacking the light chains as well as the first constant domain. The corresponding mRNA lacks the variable heavy chain (V(H)) and the constant heavy chain 1 (C(H)1) sequences and contains deletions as well as insertions of unknown origin. The encoding gene sequence reveals a deletion of V region and parts of C(H)1 domain. Cytogenetic studies demonstrated clonal rearrangements involving predominantly the heavy and light chain genes, including t(9;14) translocation involving the PAX5 gene. Early-stage IPSID responds to antibiotics (30%-70% complete remission). Most untreated IPSID patients progress to lymphoplasmacytic and immunoblastic lymphoma invading the intestinal wall and mesenteric lymph nodes, and may metastasize to a distant organ. IPSID lymphoma shares clinical, morphologic, and molecular features with MALT lymphoma, lymphoplasmacytic lymphoma, and plasma cell neoplasms.