Florid splenic gamma/delta T-cell proliferation in patients with splenomegaly and cytopenias: A "high stakes" diagnostic challenge

• Published in: Human pathology 2017-08, Vol.66, p.216-221
• Main Authors: Zhang, Shanxiang, MD, PhD, Bayerl, Michael G., MD
• Format: Article
• Language: English
• Subjects: Adult; Anemia; Biopsy; Blood platelets; Bone marrow; Cell Proliferation; Classification; Diagnosis, Differential; Female; Hepatosplenic T-cell lymphoma; Humans; Immunophenotyping; In Situ Hybridization, Fluorescence; Leukemia; Lymphocytes; Lymphoma; Lymphoma, T-Cell - genetics; Lymphoma, T-Cell - immunology; Lymphoma, T-Cell - pathology; Lymphoproliferative Disorders - genetics; Lymphoproliferative Disorders - immunology; Lymphoproliferative Disorders - pathology; Lymphoproliferative Disorders - surgery; Medical imaging; Morphology; Neutropenia; Neutrophils; Pathology; Predictive Value of Tests; Primary cutaneous γ/δ T-cell lymphoma; Receptors, Antigen, T-Cell, gamma-delta - genetics; Receptors, Antigen, T-Cell, gamma-delta - immunology; Spleen - immunology; Spleen - pathology; Spleen - surgery; Splenectomy; Splenic Neoplasms - genetics; Splenic Neoplasms - immunology; Splenic Neoplasms - pathology; Splenic T cells; Splenomegaly - genetics; Splenomegaly - immunology; Splenomegaly - pathology; Splenomegaly - surgery; T cell receptors; T-Lymphocytes - immunology; T-Lymphocytes - pathology; Treatment Outcome; Tumors; γ/δ T Cells; γ/δ T-cell large granular lymphocytic leukemia
• ISSN: 0046-8177; 1532-8392
• DOI: 10.1016/j.humpath.2017.01.015

Summary Objectives Splenic gamma/delta T-cell proliferation is rare and correct diagnosis is critical for adequate clinical management. Methods Two splenectomy cases from patients with splenomegaly and cytopenias were studied by morphological evaluation, extensive immunophenotyping, FISH and molecular studies. The clinicopathologic findings were compared with splenic T gamma/delta neoplasia, notably hepatosplenic T-cell lymphoma (HSTL) and T-cell large granular lymphocytic leukemia (TLGL) of the variety T gamma/delta. Results The enlarged spleens showed expanded red pulp with markedly increased gamma/delta T cells, which share significant to complete overlapping morphology and immunophenotype with the neoplastic gamma/delta T cells in HSTL and gamma/delta TLGL. However, they were polyclonal by molecular study and showed no evidence of isochromosome 7q. Splenectomy alone led to long-term clinical remission in both patients. Conclusions Two florid reactive splenic gamma/delta T-cell proliferations mimicking gamma/delta T-cell neoplasia were reported for the first time in English literature. Recognition of this exceedingly rare phenomenon is critical in prevention of misdiagnosis with potentially catastrophic consequences.