The spectrum of lymphoproliferative disorders in endocrine organs: from histology to molecular genetics

Lymphoproliferative disorders (LPDs) rarely involve the endocrine system, either as dissemination of a systemic condition, or as primary diseases. Due to their rarity, LPDs of endocrine organs can represent a diagnostic challenge for both pathologists and clinicians. Nevertheless, a comprehensive review of LPDs arising in endocrine organs reveals several specific clinico-pathological features that can be helpful in the correct management of the cases, from both a diagnostic and a therapeutic point of view. We designed this review with the aim of systematically addressing the morphological, immunohistochemical and genetic characteristic of LPDs of the different endocrine organs. Both lymphomas and mass forming immune cell-based inflammatory diseases, such as IgG4-related lesions, are included in the discussion. In addition, for each primary site, we propose a step-wise diagnostic approach and provide the reader with practical tools to address differential diagnostic and prognostic issues that can be useful to manage such unexpected lesions in daily practice. Finally, endocrine function in lymphoma is discussed.