Scrotum. Granular cell tumor. S100 positive, CD68 positive, inhibin positive. Lysosomes on EM. uvenile xanthogranuloma features histiocytic cells which merge with those with features of Touton-like giant cells. This lesion labels for CD68, but not for S100 or CD1a. Langerhans histiocytosis is composed of cells with more reniform nuclei, and the lesional cells label for CD1a.
Pancreatic ductal adeno. Flat sheets of cells, three dimensional balls, and microacini
Columnar cells with delicate cytoplasm and polar nuclei (basal nuclei, apical cytoplsam)
Open chromatin with prominent central single nucleolus (versus squamous cell carcinoma with nuclei with dense chromatin and several small nucleoli, and dense cytoplasm)
Signet ring cells or intercellular glandular lumens
Endosalpingiosis! Cilia! numerous chronic inflammatory cells and bland-appearing mesothelial cells. Rare cohesive epithelial fragments are present, and at high power these cells have enlarged nuclei, multiple conspicuous nucleoli, and cilia.
Hepatoblastoma. Three cell types. undifferentiated (small cells reminiscent of neuroblastoma or Wilms tumor), embryonal cells (slightly more mature cells with large nuclei, scant cytoplasm, arranged in some architectural pattern), and fetal cells (larger cells with abundant cytoplasm, smaller than mature hepatocytes).
Marginal zone lymphomas. 1. Nodal = proliferation of monocyoid B cells in a diffuse, sinusoidal or interfollicular pattern, permeates the follicles. Look for Dutcher bodies (ND- nuclear). 2. MALT = small round lymphs with lots of pale cytoplasm and indented nuclei (monocytoid B cells), plasma cells (ND), and lymphoepithelial lesions. The plasma cells are actually monoclonal! Also can see regular old reactive follicles, don't be fooled that
DARIER's Disease = This solitary keratotic papule has a somewhat endophytic growth pattern, with a central plug of keratin. There is both acantholysis and dyskeratosis. There is suprabasal acantholysis over a papillomatous superficial dermis. Above the suprabasal acantholysis, there are large, eosinophilic, rounded suprabasal cells with perinuclear halos (Corps Ronds). Above these are small dark cells with pyknotic nuclei and a millet-seed-like
Ewing/PNET. Calf of 11 year old boy. Some of these cells form rosette-like structures. At high power, the lesion comprises of fairly monotonous, small round blue cells with scant cytoplasm, high N:C ratio, and multiple cytoplasmic vacuoles. The Papanicolaou-stained material demonstrates round to oval nuclei with multiple small nucleoli and occasional mitotic figures. Immunohistochemistry shows that the cells are immunoreactive for CD99
Osteosarcoma. Had pleomorphic giant cells. The presence of spindle cells with delicate cytoplasm radiating from the nucleus suggests a sarcomatous process. This finding, in addition to the identification of pleomorphic and atypical giant cells, in the context of plasmacytoid polygonal cells, suggests osteosarcoma.
Hairy cell leukemia. Never in nodes. BLOOD: mimics aplastic anemia (has characteristic MONOCYTOPENIA and neutropenia- reason you would die from it). Very few neoplastic cells in blood. DO NOT DIAGNOSE if there are monocytes. Classic cell morphology = bigger, with nucleus 2x size of normal one and the cell size is very uniform, no transformed cells. Nuclei can be round, oval, RENIFORM, or bilobed. Chromatin is very distinct ground glass and NO
Stem cells have the potential to repair human tissue and certain internal organs by forming new cells of cartilage, bone, ligaments, tendons
Multiplex imaging of apoptosis. U2OS cells were treated with 30 μM etoposide for 18 hr to induce apoptosis. The treated cells were stained first with 7.5 μM CellEvent Caspase-3/7 Green detection reagent (green fluorescence, C10423) to detect apoptosis and Hoechst 33342 nucleic acid stain (blue fluorescence, H3570) to label nuclei, and then with 150 nM MitoTracker Deep Red FM (pink fluorescence, M22426) to label mitochondria. Following fixation
The Microscopic World
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