Rare tumors of the thyroid gland : diagnosis and WHO classification

This book documents the most important clinicopathological features of rare thyroid tumours with an emphasis (and ample documentation) on their histological and immunohistochemical aspects. Whenever necessary, namely for differential diagnosis and/or therapy purposes, molecular data are also highlighted. In order to understand the histogenesis of rare lesions and to be able to make a differential diagnosis, the editors use the WHO book for endocrine tumours (in preparation) as a framework for classifying thyroid tumours. In addition to characterizing the main histotypes of thyroid tumours, this book also provides detailed information on how to approach the diagnosis of tumours according to the major morphological/immunohistochemical characteristics, the predominant morphology and whether or not they are hereditary. This book is a valuable learning tool for those involved in the differential diagnosis of thyroid lesions. Foreword 6 Preface 7 Acknowledgements 9 Contents 10 1: Introduction 11 References 13 2: Rare Papillary Thyroid Carcinomas 15 Introduction 15 Hobnail (Micropapillary) Variant of Papillary Thyroid Carcinoma 16 Diffuse Sclerosing Variant of Papillary Thyroid Carcinoma 22 Spindle Cell Variant of Papillary Thyroid Carcinoma 22 Spindle Cell Papillary Carcinoma with Fasciitis-Like Stroma/Fibromatosis 23 Angiomatoid Variant of Papillary Thyroid Carcinoma 24 Thyroglobulin-Negative Papillary Thyroid Carcinoma 25 Papillary Thyroid Carcinomas with Unusual Immunohistochemical Reactivity 26 Mucoepidermoid Carcinoma (MEC) of the Thyroid 28 Sclerosing Mucoepidermoid Carcinoma with Eosinophilia (SMECE) 30 Tumour-in-Tumour of the Thyroid with Neoplastic Solid Cell Nest Features 31 Tumour-in-Tumour Phenomenon Due to Metastatic Disease 33 Mixed Medullary-Papillary Carcinoma 33 References 34 3: Rare Follicular Tumours 36 Introduction 36 Oncocytic (Hürthle Cell, Oxyphilic) Tumours and Oncocytic Tumours with Clear Cells 37 Oncocytic (Hürthle Cell, Oxyphilic) Carcinoma Negative for TTF-1 and Thyroglobulin 38 Oncocytic (Hürthle Cell) Tumour with Non-specific Immunoreactivity 40 Lipid-Rich Follicular Tumours 41 Follicular Tumours with Signet Ring Cells 43 Atypical Adenoma (Including Spindle Cell Adenoma) 44 Meningioma-Like Follicular Adenoma 45 Pericytic-Like Follicular Adenoma 45 Hyalinizing Trabecular Neoplasms 47 Follicular Tumours with Glomeruloid Pattern of Growth 48 Mucinous Carcinoma 49 Hyperfunctioning (Hot) Follicular Thyroid Carcinoma 51 References 52 4: Small Cell Tumours 54 Introduction 54 Poorly Differentiated Carcinoma 55 Small Cell Variant of Medullary Thyroid Carcinoma 56 Calcitonin-Negative (Atypical) Medullary Thyroid Carcinoma 57 Thyroid Lymphoma 59 Metastatic Small Cell Carcinoma 59 Carcinoma of the Thyroid with Ewing Family Tumour Elements (CEFTE) 62 References 65 5: Rare Familial Tumours 66 Introduction 66 Cribriform-Morular Variant of Papillary Thyroid Carcinoma 68 PTEN Hamartoma Tumour Syndrome (PHTS) 77 DICER1 Syndrome 81 References 84 6: Other Rare Tumours and Tumour-­Like Lesions 87 Introduction 87 Solid Cell Nests (SCNs) and Related Lesions 88 Spindle Epithelial Tumour with Thymus-Like Differentiation (SETTLE) 98 Carcinoma Showing Thymus-Like Differentiation (CASTLE) 100 Solitary Fibrous Tumour 102 Florid Papillary Endothelial Proliferation 105 Spindle Cell Haemangioma 106 Kaposi Sarcoma 107 Epithelioid Haemangioendothelioma 108 Angiosarcoma 109 Diffuse Lipomatosis 111 References 112 7: Therapeutic Options 114 Introduction 114 Hobnail Variant of Papillary Thyroid Carcinoma 115 Diffuse Sclerosing Variant of Papillary Thyroid Carcinoma 115 Oncocytic (Hürthle Cell) Carcinoma 115 Cribriform-Morular Variant of Papillary Thyroid Carcinoma 116 PTC with TERT Promoter Mutations (with or Without BRAF Mutations) 116 Poorly Differentiated Thyroid Carcinomas 116 References 116 Index 118 Front Matter ....Pages i-xiii Introduction (Manuel Sobrinho-Simões, Catarina Eloy, Isabel Amendoeira, Paula Soares, Javier Caneiro-Gómez, Miguel Melo et al.)....Pages 1-4 Rare Papillary Thyroid Carcinomas (José M. Cameselle-Teijeiro, Catarina Eloy, Isabel Amendoeira, Paula Soares, Javier Caneiro-Gómez, Miguel Melo et al.)....Pages 5-25 Rare Follicular Tumours (José M. Cameselle-Teijeiro, Catarina Eloy, Isabel Amendoeira, Paula Soares, Javier Caneiro-Gómez, Miguel Melo et al.)....Pages 27-44 Small Cell Tumours (Catarina Eloy, José M. Cameselle-Teijeiro, Isabel Amendoeira, Paula Soares, Javier Caneiro-Gómez, Miguel Melo et al.)....Pages 45-56 Rare Familial Tumours (José M. Cameselle-Teijeiro, Catarina Eloy, Isabel Amendoeira, Paula Soares, Javier Caneiro-Gómez, Miguel Melo et al.)....Pages 57-77 Other Rare Tumours and Tumour-Like Lesions (José M. Cameselle-Teijeiro, Catarina Eloy, Isabel Amendoeira, Paula Soares, Javier Caneiro-Gómez, Miguel Melo et al.)....Pages 79-105 Therapeutic Options (Miguel Melo, José M. Cameselle-Teijeiro, Catarina Eloy, Isabel Amendoeira, Paula Soares, Javier Caneiro-Gómez et al.)....Pages 107-110 Back Matter ....Pages 111-113 This book documents the most important clinicopathological features of rare thyroid tumours with an emphasis (and ample documentation) on their histological and immunohistochemical aspects. Whenever necessary, namely for differential diagnosis and/or therapy purposes, molecular data are also highlighted. In order to understand the histogenesis of rare lesions and to be able to make a differential diagnosis, the editors use the WHO book for endocrine tumours (in preparation) as a framework for classifying thyroid tumours. In addition to characterizing the main histotypes of thyroid tumours, this book also provides detailed information on how to approach the diagnosis of tumours according to the major morphological/immunohistochemical characteristics, the predominant morphology and whether or not they are hereditary. This book is a valuable learning tool for those involved in the differential diagnosis of thyroid lesionsa