Extradurale Tumoren

Approximately 50-60% of spinal tumors are extradural and depending on the origin and location are classified into tumors of the vertebrae, tumors of the epidural space and primarily extraspinal tumors growing into the spine. Presenting complaints include back pain and weakness as well as myelopathy and radiculopathy due to compression of the spinal cord or the nerve roots, respectively. Imaging of extradural tumors mostly requires both magnetic resonance imaging (MRI) and computed tomography (CT). Extradural masses and infiltration of the cord can be depicted by MRI and CT depicts osteolytic and osteosclerotic lesions and the extent of osseous involvement. Bone scintigraphy is often helpful in detecting metastases and characterizing osteoid osteomas.     

Supratentorielle Tumoren

Magnetic resonance imaging is a routine diagnostic measure for a suspected intracerebral mass. Computed tomography is usually also indicated. Further diagnostic procedures as well as the interpretation of the findings vary depending on the tumor location. This contribution discusses the symptoms and diagnostics for supratentorial tumors separated in relation to their intra- or extracranial location. Supratentorial tumors include astrocytoma, differentiated by their circumscribed and diffuse growth, ganglioglioma, ependyoma, neurocytoma, primitive neuroectodermal tumors (PNET), oligodendroglioma, dysem-bryoplastic neuroepithelial tumors (DNET), meningoangiomatosis, pineal tumors, hamatoma, lymphoma, craniopharyngeoma and metastases. The supratentorial extracranial tumors include the choroid plexus, colloid cysts, meningeoma, infantile myofibromatosis and lipoma. The most common sub-forms, especially of astrocytoma, will also be presented.     

Spinale Tumoren

Spinal tumors can be intramedullary, intradural (within the meninges), or extradural (between the meninges and the bones), or they may extend secondary to the spine from other locations. Vertebral hemangioma represents the most common benign tumor of the spine. Metastases, lymphoma, and multiple myeloma are the most frequent malignant spinal tumors. Primary osseous tumors of the spine, in contrast, are rare conditions but may demonstrate typical imaging findings. For the differential diagnosis, the patient’s age, the topographic localization of the mass, and morphologic features of the lesion as depicted by computed tomography and magnetic resonance imaging play important roles.     

Orbitale Tumoren

Computed tomography (CT) and magnetic resonance imaging are the modalities of choice in the assessment of orbital neoplasms. Careful interpretation of the characteristic radiological features usually leads to the correct diagnosis; however, some of the lesions look very similar and are difficult to differentiate from each other. This contribution provides an overview of tumors of the eye and orbit and their appearance on CT and magnetic resonance imaging.     

Nephrogene Tumoren

Nephroblastomas are the most common malignant renal tumors in childhood. According to the guidelines of the SIOP (Société Internationale d’Oncologie Pédiatrique) and GPOH (Gesellschaft für Pädiatrische Onkologie und Hämatologie) pre-operative chemotherapy can be started without histological confirmation and thus initial imaging studies, in particular ultrasound, play an outstanding role for diagnostic purposes.     

Endokrine Tumoren

The term endocrine tumor incorporates all neoplasms which originate from the various endocrine organs. Endocrine tumors can be characterized by different criteria: localization, endocrine function, dignity (i.e. tumorigenesis, sporadic or hereditary). These characteristics also determine the clinical outcome. The clinical history, symptoms and physical examination findings (e.g. amenorrhea, skin alterations, striae, virilization, increased blood pressure and flush) direct the diagnostic process of functioning endocrine tumors. Laboratory findings (endocrine parameters) are needed to establish a diagnosis supplemented by imaging for localization and special investigations (ophthalmological examination). In hereditary tumor syndromes, the familial history and molecular genetic testing and screening of family members are essential for establishing the diagnosis and achieve optimal and early treatment. Ideally, affected family members can be treated before clinical symptoms or metastatic disease occurs, improving outcome and prognosis. Incidentalomas are increasingly found due to widespread use of imaging techniques, especially in the thyroid, adrenal glands, pancreas and pituitary gland. In incidentalomas the functional status and risk of malignancy has to be evaluated as both parameters determine therapy decisions. The aim of this introductory article is to give an overview about particular features of endocrine tumors, clinical and related aspects for the diagnostic and therapeutic approach. The clinical features of tumors of the pituitary, parathyroid and adrenal glands and the gastroenteropancreatic system are summarized according to localization.     

Tumoren der Sellaregion

Because of the complex anatomy, examination of the sella turcica and hypophysis needs a dedicated MR sequence protocol. Not every sellar lesion is a pituitary adenoma. Thus, this review article summarizes the most frequently encountered intra-, supra-, and parasellar tumors and lesions. Differential diagnoses comprise besides adenoma among others craniopharyngioma, meningioma, glioma, germinoma, hamartoma, aneurysm, trigeminal schwannoma, pituitary carcinoma, chordoma, metastasis, infection, and empty sella. Characteristic imaging findings are presented and correlated to micro- and macro-pathology.     

Gastroenteropankreatische endokrine Tumoren

Clinical/methodical issue

Gastroenteropancreatic neuroendocrine tumors (GEP-NET) are a rare, heterogeneous group of neoplasms. Only 2?% of gastrointestinal tumors belong to the group of neuroendocrine neoplasms.

Standard radiological methods

A wide spectrum of diagnostic imaging modalities is available: apart from ultrasound not only computed tomography (CT) but also magnetic resonance imaging (MRI) and positron emission tomography CT (PET-CT) play an important role in detection and staging of GEP-NETs.

Methodical innovations

The PET-CT technique with somatostatin analogues is used for staging as well as for evaluation and monitoring of treatment with peptide radionuclide radiation therapy.

Performance

According to the literature NETs of the small bowel with a size over 3 cm can be detected with a sensitivity of 84.7?% and a specificity of 96.6?% using CT enteroclysis and MR enteroclysis provides the detection of NETs of the small bowel in 93.3?% of cases. ’The sensitivity of MRI in detection of pancreatic NETs is between 74?% and 100?% and is, therefore, higher than CT. Detection of small primary tumors is carried out using PET-CT and seems to be the most sensitive imaging modality to identify the exact location. On the other hand MRI has to be regarded as the best imaging modality for detection of liver metastases compared to CT and PET-CT.

Achievements

The role of diagnostic imaging is to identify the exact location of the primary tumor and possible metastases, to define an appropriate therapy and to monitor treatment effects; however, the choice of the most appropriate diagnostic imaging modality varies depending on the location and type of the primary tumor.

Practical recommendations

The GEP-NETs are predominantly well-vascularized; therefore, dual-phase CT/MR imaging with the arterial and venous phases after contrast media injection is mandatory for detection and localization of primary tumors and metastases. For whole body staging CT and PET-CT should be performed.     

Gutartige knochenbildende Tumoren

Zu den gutartigen knochenbildenden Tumoren z?hlen das Osteom, Enostom, Osteoidosteom und das Osteoblastom. Sie sind oft durch einen typischen Befund im R?ntgenbild oder auch in anderen radiologischen Verfahren charakterisiert. Aus der Zusammenschau von radiologischem Befund und klinischen Informationen kann h?ufig bereits eine spezifische Diagnose gestellt werden. Dieser übersichtsartikel stellt neben dem radiologischen Erscheinungsbild der Tumoren auch die für die Diagnostik wichtigsten Aspekte von Epidemiologie, klinischer Symptomatik und pathologischen Befunden dar. Auch auf die radiologisch-interventionellen Therapiem?glichkeiten beim Osteoidosteom wird eingegangen.     

Differenzialdiagnose spinaler Tumoren

A wide variety of degenerative, inflammatory and vascular diseases can resemble the clinical presentation and imaging findings of spinal tumors. This article provides an overview of the most frequent diseases which are important to recognize for diagnostic imaging of the spine.     

Tumoren der Sellaregion

Tumors of the pituitary gland can lead to limitation of hypophysis function (hypophysis insufficiency) or hypersecretion of different hormones (acromegaly, Cushing’s syndrome, prolactinoma, TSH-secreting adenoma). The optic chiasma lies in close proximity to the pituitary gland and can be compressed by tumors leading to visual disturbances (bilateral hemianopsia). Tumors can be separated into hormone secreting and hormone inactive tumors, as well as into microadenoma with a diameter <10 mm and macroadenomas >10 mm. A rare group of tumors of the hypophysis region are craniopharyngiomas, meningiomas, germinomas, gliomas, metastases and granulomotous inflammations, such as sarcoidosis and tuberculosis.     

Tumoren der Nebennieren

Clinical/methodical issue

Adrenal masses are very common and are usually detected incidentally. Less frequently, imaging is performed for the localization of the underlying lesion in the case of endocrine disease. The differentiation between adenomas and non-adenomas is fundamental.

Methodical innovations

Adenomas show a low density on unenhanced computed tomography (CT) and a rapid washout of contrast agents. In magnetic resonance imaging (MRI) adenomas are characterized by a low signal in opposed phase imaging as compared to in phase imaging.

Performance

According to the literature a density of less than 10 HU in an adrenal mass has a specificity of 98?% and a sensitivity of 71?% for the presence of an adenoma and MRI is slightly more sensitive. Some adrenal lesions, e.g. cysts or myelolipomas can be diagnosed with high accuracy due to pathognomonic findings.

Achievements

In the majority of cases the synopsis of imaging along with clinical and laboratory findings is necessary for a reliable diagnosis.

Practical recommendations

For the evaluation of an adrenal mass the CT examination should begin with an unenhanced scan, if necessary followed by a washout examination. In the case of MRI in phase and opposed phase imaging are essential components of the examination.     

Intrakranielle Tumoren im Kindesalter

Every year, 400 children suffer from a brain tumor. These are the most frequent solid tumors in the pediatric patient. They represent a very heterogenic group of tumors with different clinical symptoms, pathology, therapy and prognosis. Imaging modalities such as CT and MRI are important for the diagnosis and follow-up after therapy. Brain tumors in children are responsible for 15-20% of all brain tumors. Tumors of the central nervous system are the second most common tumors after leukemia. Infra- and supratentorial tumors occur in equal number, however, there are differences in the age of occurrence: supratentorial tumors occur more often within the first 2-3 years of life, whereas infratentorial tumors reach there peak between 4 and 10 years. After the tenth year, infra- and supratentorial tumors occur with equal frequency.     

Tumoren des weiblichen Beckens

Cervical, endometrial and ovarian carcinomas are the main malignant neoplasms of the female pelvis. For CT, a thin-slice venous phase with good bowel contrast is used. For MRI, an anti-peristaltic agent is necessary. Thin-slice T2- weighted TSE images with a high in-plane spatial resolution are particularly suitable for imaging the uterine wall; a parenteral contrast medium is absolutely necessary to demonstrate endometrial and ovarian carcinoma. In the guidelines, MRI is recommended only for cervical cancer FIGO 1b and higher stages; nevertheless, CT and MRI play an important role in preoperative diagnosis of these tumors. Lymph node staging is performed during surgery where possible. In patients with endometrial carcinoma, preoperative staging focuses on the infiltration depth in the myometrium. Preoperative diagnosis of ovarian cancer centers on any tumor spread in the abdomen, and diagnostic imaging methods are designed to provide the surgeon with information about compartments of a possible peritoneal carcinosis that are difficult to see. In patients with incidental findings of ovarian masses, CT and MRI can detect evidence of malignancy, although an exact differential diagnosis is not usually possible in this very heterogeneous group of ovarian tumors.     

Nuklearmedizinische Therapie endokriner Tumoren

This article gives an overview of the established radionuclide therapies for endocrine-related cancer that already have market authorization or are currently under evaluation in clinical trials. Radioiodine therapy is still the gold standard for differentiated iodine-avid thyroid cancer. In patients with bone and lung metastases (near) total remission is seen in approximately 50?% and the 15-year survival rate for these patients is approximately 90?%. In contrast to the USA, meta-iodobenzylguanidine (MIBG) therapy has market approval in Europe. According to the current literature, in the setting of advanced stage neuroblastoma and malignant pheochromocytoma or paraganglioma, radiological remission can be achieved in >?30?% and symptom control in almost 80?% of the treated patients. Somatostatin receptor targeted radionuclide therapies (e.g. with DOTATATE or DOTATOC) demonstrated promising results in phase 2 trials, reporting progression-free survival in the range of 24–36 months. A first phase 3 pivotal trial for intestinal carcinoids is currently recruiting and another trial for pancreatic neuroendocrine tumors is planned. Radiopharmaceuticals based on glucagon-like peptide 1 (GLP1) or minigastrins are in the early evaluation stage for application in the treatment of insulinomas and medullary thyroid cancer. In general, radiopharmaceutical therapy belongs to the group of so-called theranostics which means that therapy is tailored for individual patients based on molecular imaging diagnostics to stratify target positive or target negative tumor phenotypes.     

Zystische Tumoren des Pankreas

Due to the widespread use of computed tomography (CT) and magnetic resonance imaging (MRI) of the abdomen, the incidence of cystic pancreatic lesions as an incidental finding in asymptomatic patients is increasing; however, most of these lesions are less than 2 cm in size at the time of diagnosis making a correct classification difficult. A more differentiated understanding of the pathophysiology of these lesions has been developed during recent years. Technical improvements in imaging techniques have resulted in an increase in image resolution and has enabled radiologists to differentiate between intraductal papillary mucinous neoplasms (IPMN), serous cystic neoplasms (SCN) and mucinous cystic neoplasms (MCN). A correct classification, including the differentiation from malignant pancreatic tumors, can only be achieved by combining the knowledge of lesion pathophysiology and basic epidemiological data, such as age and sex distribution with modern imaging techniques. In conjunction with the correct diagnosis, the radiologist has to decide on the further management of the newly found lesion. This differs greatly depending on the biological behavior, especially the potential for malignant transformation, e.g. in main duct IPMN. This review gives an overview of the different cystic pancreatic lesions, their underlying pathophysiology and imaging characteristics along with recommendations for the further clinical management.