Frequent mitoses and few tumor giant cells were regarded along with subendothelial infiltrate and occasional pseudorosette
(Figures 6 and 7).
These cells demonstrated perivascular distribution in a pseudorosette
pattern with broad cytoplasmic processes radiating toward the centrally placed blood vessels (Figure 5).
Nodular hidradenomas also lack the uniform cells, "salt and pepper" chromatin, pseudorosette
formation, and mucin production seen in EMPSGC.
Differentiating features for AIH from SLE-related liver disease are portal and periportal inflammation, piecemeal necrosis with dense lymphoid infiltrates, dominant portal tract plasma cell infiltration, hepatocyte pseudorosette
formation whereas lupus-associated hepatitis shows predominantly lobular involvement with mild lobular inflammation and no piecemeal necrosis 19].
The cells ranged in size with scant and fragile cytoplasm, high nuclear/cytoplasmic ratios, hyperchromatic, angulated nuclei showing nuclear molding, focal pseudorosette
formations, granular chromatin and inconspicuous nucleoli and some mitotic figures.
of Cases Percentage Poorly differentiated 15 35.7 Moderately differentiated 22 52.3 Well differentiated 5 11.9 Rosette Flexner-Wintersteiner 13 30.9 Pseudorosette
29 69.0 Microscopic Spread Optic nerve 16 38 Skeletal muscle 1 2.3 Lacrimal gland 2 4.7 Vascular emboli 2 4.7 Others Necrosis 34 80.9 Dystrophic calcification 11 26.1 Haemorrhage 10 23.8 Siderosis 4 9.5 Cholesterol slits 3 7.1 Basophilia 3 7.1
The distinguishing histologic characteristic is perivascular pseudorosette
The spindle cells show pseudorosette
around capillaries, scanty cytoplasm, mild pleomorphism and dense hyperchromatic nuclei.
Glandular and pseudorosette
formations may be seen.
Centrilobular canalicular cholestasis with acinar or pseudorosette
formation is the predominant finding (Figure 8).
(1,2,4) Nuclear palisading around the stromal cores and pseudorosette
formation around capillary vessels are also common features (Figure 1, A through D).
All 5 tumors consisted of an angiocentric growth pattern of bipolar spindle cells with slender nuclei that radiate from a central vessel to form pseudorosette
structures (Figure 1, B).