ABSTRACT
Hemangiopericytomas are rare soft-tissue neoplastic lesions that can arise in any part of the body. They are mesenchymal tumors that account for 3 to 5% of all soft-tissue sarcomas and 1% of all vascular tumors. They originate in extravascular cells (pericytes). Some 15 to 30% of all hemangiopericytomas occur in the head and neck; of these, approximately 5% occur in the sinonasal area. We describe our brief retrospective review of 7 histologically proven cases of sinonasal hemangiopericytoma, and we discuss the imaging characteristics and clinical and pathologic findings in these patients.
Subject(s)
Hemangiopericytoma/pathology , Nose Neoplasms/pathology , Adult , Aged , Epistaxis/surgery , Female , Hemangiopericytoma/diagnostic imaging , Hemangiopericytoma/surgery , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Nose Neoplasms/diagnostic imaging , Nose Neoplasms/surgery , Paranasal Sinus Neoplasms/diagnostic imaging , Paranasal Sinus Neoplasms/pathology , Paranasal Sinus Neoplasms/surgery , Radiography , Retrospective StudiesABSTRACT
The purpose of this article is to review the imaging findings of the different expansile lesions of the thymus. Almost 50% of all mediastinal masses are located in the anterior mediastinum. The thymus is the most common site of origin of these masses. Several kinds of lesions can arise from this gland because it derives from the three embryonic germ cell layers. Primary neoplasms of the thymus are thymoma, thymolipomas, carcinoma, carcinoid, primary germ cell tumors, and lymphoma. The latter can also involve the organ in a secondary fashion. Other lesions that cause thymic enlargement and that can be confused with neoplasia are thymic cysts and thymic hyperplasia. Even though anterior mediastinal masses are first found on conventional radiographs, computed tomography and magnetic resonance are very useful additional studies for assessing the origin and extension of these masses. The basic concepts regarding embryology, anatomy, and histology relevant for the differential diagnosis of an enlarged thymic gland are also described.
Subject(s)
Lymphatic Diseases/diagnosis , Thymus Gland , Thymus Neoplasms/diagnosis , Diagnosis, Differential , Lymphatic Diseases/diagnostic imaging , Magnetic Resonance Imaging , Mediastinal Cyst/diagnosis , Mediastinal Cyst/diagnostic imaging , Radiography, Thoracic , Thymus Neoplasms/diagnostic imaging , Tomography, X-Ray ComputedABSTRACT
"Inflammatory pseudotumor" is a broad descriptive term used to describe a localized collection of inflammatory and fibroblastic cells. It is an uncommon lesion that can mimic a tumor when it is located intraluminally in the trachea or bronchi. Because an inflammatory pseudotumor has an abundance of polyclonal plasma cells, its etiology (postinflammatory vs immunologic) is still being debated. We report a new case of inflammatory pseudotumor that arose in the trachea of a 20-year-old man. We also review the histologic and clinical characteristics of this lesion.
