title: Pulmonary neuroendocrine carcinoma mimicking neurocysticercosis: a case report.
abstract: BACKGROUND
  Neurocysticercosis occurs when the eggs of the pork tapeworm (Taenia solium) migrate and hatch into larvae within the central nervous system. Neurocysticercosis is the most common cause of seizures in the developing world and is characterized on brain imaging by cysts in different stages of evolution. In Canada, cases of neurocysticercosis are rare and most of these patients acquire the disease outside of Canada. We report the case of a patient with multiple intracranial lesions whose history and diagnostic imaging were consistent with neurocysticercosis. Pathological investigations ultimately demonstrated that her brain lesions were secondary to malignancy. Brain metastases are considered to be the most common cause of intracranial cystic lesions.
  
  
  METHODS
  We present the case of a 60-year-old Canadian-born Caucasian woman with a subacute history of ataxia, lower extremity hyper-reflexia, and otalgia who resided near a pig farm for most of her childhood. Computed tomography and magnetic resonance imaging showed that she had multiple heterogeneous intracranial cysts, suggestive of neurocysticercosis. Despite a heavy burden of disease, serological tests for cysticercosis were negative. This result and a lack of the central scolices on neuroimaging that are pathognomonic of neurocysticercosis prompted whole-body computed tomography imaging to identify another etiology. The whole-body computed tomography revealed right hilar lymphadenopathy associated with soft tissue nodules in her chest wall and abdomen. A biopsy of an anterior chest wall nodule demonstrated high-grade poorly differentiated carcinoma with necrosis, which stained strongly positive for thyroid transcription factor-1 and synaptophysin on immunohistochemistry. A diagnosis of stage 4 metastatic small cell neuroendocrine carcinoma was made and our patient was referred for oncological palliative treatment.
  
  
  CONCLUSIONS
  This case illustrates the importance of the diagnostic approach to intracranial lesions. Our patient's diagnosis of neuroendocrine carcinoma was delayed because of her nontraditional presentation. Despite extensive metastatic burden, the lack of perilesional edema and the identification of lesions appearing to be in various stages of development led to a pursuit of neurocysticercosis as the diagnosis. The absence of constitutional symptoms should not discount the possibility of malignancy from the differential diagnosis.
authors.affiliation: Department of Medicine, The University of Calgary, Calgary, AB, T2N 2T9, Canada. john.c.lam@ucalgary.ca.
authors.forename: John C
authors.initials: JC
authors.lastname: Lam
authors.affiliation: Department of Medicine, The University of Calgary, Calgary, AB, T2N 2T9, Canada.
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Robinson
authors.affiliation: Department of Pathology and Laboratory Medicine, The University of Calgary, Calgary, AB, T2N 2T9, Canada.
authors.forename: Andrew
authors.initials: A
authors.lastname: Schell
authors.affiliation: Department of Medicine, The University of Calgary, Calgary, AB, T2N 2T9, Canada.|Department of Infectious Disease, The University of Calgary, Calgary, AB, T2N 2T9, Canada.|Foothills Medical Center, The University of Calgary, 1403 29 Street NW, Calgary, AB, T2N 2T9, Canada.
authors.forename: Stephen
authors.initials: S
authors.lastname: Vaughan
mesh_terms: D034861:Abdominal Wall / Q000000981:diagnostic imaging; D001921:Brain / Q000000981:diagnostic imaging*; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism / Q000556:secondary*; D018278:Carcinoma, Neuroendocrine / Q000000981:diagnostic imaging / Q000378:metabolism / Q000556:secondary*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D000072281:Lymphadenopathy; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D020019:Neurocysticercosis / Q000000981:diagnostic imaging*; D009687:Nuclear Proteins / Q000378:metabolism; D012983:Soft Tissue Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism / Q000556:secondary*; D016708:Synaptophysin / Q000378:metabolism; D035441:Thoracic Wall / Q000000981:diagnostic imaging; D000074482:Thyroid Nuclear Factor 1; D014057:Tomography, X-Ray Computed; D014157:Transcription Factors / Q000378:metabolism
chemical_list: C000614412:NKX2-1 protein, human; D009687:Nuclear Proteins; D016708:Synaptophysin; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors
keywords: Adenocarcinoma; Brain; Cysts; Metastases; Neurocysticercosis