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.

Hodgkin lymphoma involving the lung may present in a variety of radiographic and clinical patterns including solid or necrotizing lesions, with or without associated mediastinal adenopathy. Cavitary pulmonary lesions are exceedingly rare, occurring in less than 1% of cases, and are typically solitary. We report a case of an 18-year-old male presenting with multiple cavitating pulmonary nodules and a palpable mass in the neck. Imaging revealed associated mediastinal and cervical adenopathy. Biopsy of the neck mass and lung nodule initially revealed necrosis and granulomata, suggesting infection. Treatment for a presumed infectious etiology was without resolution. Subsequent open lung biopsy revealed marked granulomatous inflammation with diagnostic Reed-Sternberg cells. Hodgkin lymphoma should always be considered in the differential diagnosis of cavitary pulmonary lesions, especially those refractory to treatment.

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