Screening for tumours in paraneoplastic syndromes: report of an EFNS Task Force

Abstract

Background Paraneoplastic neurological syndromes (PNS) almost invariably predate detection of the malignancy. Screening for tumours is important in PNS as the tumour directly affects prognosis and treatment and should be performed as soon as possible. Objectives An overview of the screening of tumours related to classical PNS is given. Small cell lung cancer, thymoma, breast cancer, ovarian carcinoma and teratoma and testicular tumours are described in relation to paraneoplastic limbic encephalitis, subacute sensory neuronopathy, subacute autonomic neuropathy, paraneoplastic cerebellar degeneration, paraneoplastic opsoclonus-myoclonus, Lambert-Eaton myasthenic syndrome (LEMS), myasthenia gravis and paraneoplastic peripheral nerve hyperexcitability. Methods Many studies with class IV evidence were available; one study reached level III evidence. No evidence-based recommendations grade A–C were possible, but good practice points were agreed by consensus. Recommendations The nature of antibody, and to a lesser extent the clinical syndrome, determines the risk and type of an underlying malignancy. For screening of the thoracic region, a CT-thorax is recommended, which if negative is followed by fluorodeoxyglucose-positron emission tomography (FDG-PET). Breast cancer is screened for by mammography, followed by MRI. For the pelvic region, ultrasound (US) is the investigation of first choice followed by CT. Dermatomyositis patients should have CT-thorax/abdomen, US of the pelvic region and mammography in women, US of testes in men under 50 years and colonoscopy in men and women over 50. If primary screening is negative, repeat screening after 3–6 months and screen every 6 months up till 4 years. In LEMS, screening for 2 years is sufficient. In syndromes where only a subgroup of patients have a malignancy, tumour markers have additional value to predict a probable malignancy.

Renal Cell Carcinoma Presenting with Paraneoplastic Hallucinations and Cognitive Decline from Limbic Encephalitis

“…11 Preferably, this will include an entire panel of paraneoplastic antibodies rather than one or two specific antibodies, as overlap in syndrome presentation is common. Results of antibody testing should help guide further imaging studies (Table 1).…”

“…11,12 If primary screening is negative, it is recommended to repeat screening in 3-6 months, and then every 6 months for up to 4 years. 11,12 The primary treatment of paraneoplastic neurological disorders is prompt removal and treatment of the tumor. Clinical outcomes vary, and appear to be influenced by the underlying malignancy and associated antibodies ( Table 2).…”

Immune Mediated Diseases and Immune Modulation in the Neurocritical Care Unit

“…Idiopathic limbic encephalitis may be suggested by the presence of high titers of VGKC antibodies, although this finding is not specific as patients with paraneoplastic limbic encephalitis may occasionally have high serum titers of VGKCs as well [236]. Patients with a clinical diagnosis of limbic encephalitis should be screened for potential malignancies [237].…”

Autoimmune encephalitis

“…Первая группа получила название «истинные» паранеопластические ан-титела -это антитела к внутриклеточным белкам, кото-рые в настоящий момент определяются только при пара-неопластических неврологических синдромах -Hu, Yo, Ma2, CV2, amphiphysin. Выявление любого из этих АТ в ОБЗОРЫ абсолютном большинстве (>95%) случаев отражает нали-чие паранеопластического процесса даже при отсутствии обнаружения опухоли в данный момент и требует обяза-тельного длительного онкопоиска (не менее 5 лет) [6]. Вторую группу составляют АТ, которые могут определять-ся как при энцефалитах на фоне онкологического процес-са, так и при идиопатических АЭ.…”