GAMMA HEAVY CHAIN DISEASE; HISTOPATHOLOGICAL FEATURES IN BONE MARROW AND LYMPH NODE, CASE REPORT, Florence, Italy, 17 - 22 September 2022, pp.64
Case Description: A 31-year-old female patient from Djibouti/North Africa had a complaint of neck swelling for one year. No other symptoms were described. It was reported that she was diagnosed with lymphoma (Hodgkin? Non-Hodgkin?, pathology report not available) in her country but was not treated. In PET-CT images, lymph nodes with 17-27 mm diameters (SUVmax: 2.4-4.0) were detected in the left cervical lymphatic stations, bilateral axilla, mediastinum, paraaortocaval regions, bilateral iliac chain and inguinal fossa. Spleen size increased and intraparenchymal FDG uptake was slightly increased homogeneously. A few millimetric nodular areas of density increase were observed in both lung parenchyma. In biochemistry and hemogram tests; Albumin:3.8, Total Protein:5.6, Urea:23, Urate:6.8, Creatinine:0.56, LDH:194, WBC:2430, Neutrophil:1800, Lymphocyte:410, Hb:7.48, Hct:22.87, Plt:121000. Beta-2 microglobulin: 3.26, Kappa(total, serum):0.9, Lambda(total, serum):0.5, IgA:48(65-421), IgG:1586(552-1631), IgM:21(33-293). No kappa or lambda light chain detected in urine immunofixation electrophoresis. IgG monoclonal band observed in serum immunofixation electrophoresis. Hepatic viral markers and HIV were negative. Left supraclavicular lymph node excision and bone marrow biopsy were evaluated in our department.
Biopsy Fixation Details: 10% neutral buffered formalin. Bone marrow biopsy was decalcified in 10% formic acid for 8 hours.
Frozen Tissue Available: -
Details of Microscopic Findings:
Lymph node: The architecture was totally effaced. There was atypical infiltration in diffuse and coarse nodular pattern consisting of polymorphic cells. Most of the atypical cells had a plasmacytoid morphology. Small-medium sized lymphoid cells with coarse chromatin were accompanying the plasmacytoid cells. Scattered atypical lymphocytes were observed, some resembling Reed-Sternberg cells, with large round/lobulated nuclei, vesicular chromatin, and prominent single or few small nucleoli.
Bone marrow: The biopsy with six intertrabecular field was hypercellular. Alternating areas with light/dark staining and vague nodulation foci were seen. Hematopoietic cells were pushed to the paratrabecular zone by atypical infiltration. The atypical infiltration was composed of a polymorphic cellular population in this biopsy as well. Numerous plasma cells were observed in the periphery of the nodular areas. In the center of the nodules, small-medium sized lymphoid cells with coarse chromatin and scant cytoplasm were present. In a focal area atypical lymphoid cells were mixed with epithelioid histiocytes. Clusters of medium-sized lymphoid cells with vesicular chromatin were seen in some areas. Occasionally, eosinophils were also accompanying.
Lymph node: CD20:(Positive in atypical B lymphocytes), CD138:(Positive in atypical plasma cells), IgG-MUM1:(Positive in atypical cellular population), Kappa-Lambda-IgG4-IgD-IgA-IgM:(Positive in rare reactive plasma cell), CD30:(Positive in Reed-Sternberg-like cells), CD15:(-), Fascin:(-), HHV8:(-).
Bone marrow: CD138-CD38:(Positive in atypical plasma cells), CD19-CD20:(Positive in atypical B lymphocytes), CD3:(Positive in abundant reactive T lymphocytes), IgG:(Positive in atypical cellular population), Kappa-Lambda-IgG4-IgD-IgA-IgM:(Positive in rare reactive plasma cell).
Molecular Studies: EBER:(-)
Proposed Diagnosis: Gamma heavy chain disease
Interesting Feature(s) of Submitted Case: This neoplasm is a very rare immunosecretory disorder. Atypical infiltration was morphologically similar to lymphomas with plasmacytoid differentiation. Some of the atypical cells in lymph node sections had Reed Sternberg-like morphology.