Abstract Hematological manifestations of immunoglobulin (Ig)G4-related disease (IgG4-RD) are atypical, and few studies have addressed cytopenia in this condition. We present here a case of IgG4-RD with marked pancytopenia and splenomegaly in the absence of bone marrow abnormalities. A 67-year-old woman developed diplopia, dyspnea, pancytopenia, and hypocomplementemia. Contrast-enhanced computed tomography showed bilateral lacrimal and submandibular gland swellings, enlargement of cervical, mediastinal, inguinal, and para-aortic lymph nodes, splenomegaly, and granular shadows in both lungs. She had been referred to our hospital on suspicion of malignant lymphoma, but lymph node biopsy indicated the possibility of IgG4-RD. Lacrimal gland biopsy showed infiltration of numerous lymphocytes and IgG4-positive plasma cells along with mild fibrosis. Bone marrow biopsy showed normocellular marrow with no increase in plasma cells. The IgG4-positive plasma cell count was 4 per high-power field, with an IgG4/IgG ratio of 10%. After excluding potential mimics, the diagnosis was IgG4-RD presenting with pancytopenia and splenomegaly. Prednisolone was initiated at 40 mg/day, leading to rapid normalization of pancytopenia, recovery of complement levels, and resolution of other organ involvements such as splenomegaly. Physicians should keep in mind that IgG4-RD can present as pancytopenia and splenomegaly.
Ikeda et al. (Wed,) studied this question.