Gross and microscopic appearance of the tumor. a. A photograph of the cut surface of the tumor. A multilobular cyst with a yellowish necrotic solid part was observed. Both ovaries were normal. b. Histopathological features of the tumor. Clear cells lined the glandular and papillary structure. A hobnail arrangement of the cells was seen (hematoxylin and eosin; original magnification: ×400).