(16) Cells in pseudotumoral deciduosis show less atypia and pleomorphism than does PMDM with no
mitotic figures. (1, 9) Expression of estrogen and progesterone receptors and [alpha]-inhibin by decidual cells in pseudotumoral deciduosis is also discriminative because those markers are negative in PMDM.
Although it had an MIB-1 proliferation index higher than 10% and some
mitotic figures, it was considered as benign because of the young of age of the patient and its superficial location.
The bland spindle cells usually show scant cytoplasm and occasionally
mitotic figures. In the infiltrates and scattered lymphocytes, germinal centers can often be identified.
Neoplastic cells (asterisk) have many
mitotic figures, moderate anisokaryosis and anisocytosis, small amounts of eosinophilic cytoplasm, and round or indented nuclei (B).
Caption: Figure 2: (a) Histologic sections showing a cellular proliferation of pleomorphic cells, some of which are multinucleated (H&E stain, 100x original magnification); lymphocytic infiltration is also seen (b); (c) neoplastic cells show eosinophilic cytoplasm and intracytoplasmic vacuoles, with
mitotic figures identified (H&E stain, 400x original magnification); immunohistochemistry shows diffuse reactivity for S-100 (d), GFAP (e), and neurofilament (f); the Ki-67 proliferative index is moderately elevated (g).
(c) H&E staining demonstrated a highly cellular, atypical complex vascular lesion with rare
mitotic figures. (d) MIB-1 staining illustrates a proliferation index of approximately 10%.
Well-differentiated neoplastic cells have
mitotic figures less than 2 per 10 HPF with mild cellular atypia.
Caption: Figure 2: Microscopic appearance of the ileal malignant GIST (stained with eosin/hematoxylin stain) under high-power magnification showing
mitotic figures. (a) Tumor cells exhibiting epithelioid morphology (H&E; 20x).
Histopathology revealed pleomorphic tumor cells with pleomorphic round to oval eccentric nuclei, prominent eosinophilic nucleoli, multinucleate giant cells with intracytoplasmic melanin pigment, and atypical
mitotic figures (Figure 2b).
Numerous keratin pearls and few
mitotic figures with cellular and nuclear pleomorphism and hyperchromatism were also seen.
Histopathological examination revealed group of cells composed of haphazard arrangement of a mixture of large epithelioid, plasmacytoid and spindle cells with increased nuclear cytoplasmic ratio, nuclear pleomorphism and several
mitotic figures (Figure 2).
(4) The following histological features are predictive of malignancy in AML: >70% atypical epithelioid cells, >2
mitotic figures per 10 high-power field (HPF), atypical
mitotic figures, and necrosis.