Fig. 1

Diagnosis of PLE associated with lymph node metastases of a small cell neuroendocrine carcinoma. a-b T2-weighted FLAIR signal of the para hippocampic gyrus and the hippocamps (brain MRI: coronal and axial section; red arrows). c-d Left, hypermetabolic peri-aortic and supraclavicular lymph node (PET-scan; red arrows). e Right hypermetabolism of the hippocampus (PET-scan; red arrow) and a right prefrontal, parietal and occipital hypometabolism (white arrows). f Massive tumor infiltration of poorly differentiated cells with scant cytoplasm, coarse chromatin, prominent mitotic and apoptotic figures, associated to a diffuse necrosis (histology; hematoxylin and eosin stain, 200x). g Positivity of tumor cells for CD56 (immunohistochemistry; 400x)