Fig. 1

Structural pattern of microcystic urothelial carcinoma. MUC exhibited microcystic (a), gland-like tubular (b), cribriform (c), and occasional cord-like structures (d); most areas lacked a stromal response. The cysts and tubules contained eosinophilic secretions (b), were empty (d), or were filled with mucin (e). Lymph node metastases (f), perineural invasion (g), and vascular invasion (h) were detected in individual cases