SMALL CELL CARCINOMA IN EFFUSION Figure 3-79 SMALL CELL CARCINOMA IN EFFUSION The cell block shows uniform chromatin, nuclear molding, and scant cytoplasm, supportive diagnostic features. More

EPITHELIOID MESOTHELIOMA Figure 3-22 EPITHELIOID MESOTHELIOMA Areas of single cell infiltration may be present. More

EPITHELIOID MESOTHELIOMA: WITH CLEAR CELLS Figure 3-39 EPITHELIOID MESOTHELIOMA: WITH CLEAR CELLS The cytoplasm of the tumor cells is variably clear. More

EPITHELIOID MESOTHELIOMA: SMALL CELL Figure 3-43 EPITHELIOID MESOTHELIOMA: SMALL CELL Left: Solid nests of small cells are seen at medium power. Right: At high power, nests of closely packed tumor cells show nucleoli and a few mitoses, suggesting small cell carcinoma. More

REACTIVE MESOTHELIAL ATYPIA Figure 3-83 REACTIVE MESOTHELIAL ATYPIA Reactive mesothelial cell clusters have nuclei showing nucleoli and coarse chromatin, an overlapping feature with malignancy. More

MESOTHELIAL CELL: CYTOMORPHOLOGY Figure 3-86 MESOTHELIAL CELL: CYTOMORPHOLOGY An intercellular space, or “window,” and a blurry outer rim of mesothelial cells are present. More

MESOTHELIAL CELL: IMMUNOHISTOCHEMISTRY Figure 3-87 MESOTHELIAL CELL: IMMUNOHISTOCHEMISTRY Left: Calretinin immunoreactivity should be nuclear but is often accompanied by cytoplasmic staining. Right: WT-1 immunoreactivity is nuclear in mesothelial cells. More

EPITHELIOID MESOTHELIOMA: CYTOLOGY Figure 3-92 EPITHELIOID MESOTHELIOMA: CYTOLOGY Cell clusters (A), acini (B), papillary architecture (C), and psammoma bodies (D) are seen. While these can be seen in mesothelioma, individually these features overlap with reactive mesothelial cells and carcinoma.... More

EPITHELIOID MESOTHELIOMA: MTAP STAIN Figure 3-105 EPITHELIOID MESOTHELIOMA: MTAP STAIN A,B: In a cell block stained with H&E (A), MTAP expression is lost in the mesothelioma cells, while it is retained in histiocytes and inflammatory cells (B). C,D: MTAP expression is lost in mesothelioma ce... More

SQUAMOUS CELL CARCINOMA Figure 3-119 SQUAMOUS CELL CARCINOMA p40 shows strong nuclear staining in this squamous cell carcinoma. More

DESMOPLASTIC SMALL ROUND CELL TUMOR Figure 5-11 DESMOPLASTIC SMALL ROUND CELL TUMOR A,B: Islands of small round hyperchromatic cells lie in dense fibrous stroma. C,D: Tumor cells stain for both cytokeratins (C) and desmin (D). More

PRIMARY EFFUSION LYMPHOMA Figure 6-1 PRIMARY EFFUSION LYMPHOMA Sheets of monotonous large blastic lymphoid cells are present within a cell block from a pleural effusion. More

DIFFUSE LARGE B-CELL LYMPHOMA ASSOCIATED WITH CHRONIC INFLAMMATION Figure 6-4 DIFFUSE LARGE B-CELL LYMPHOMA ASSOCIATED WITH CHRONIC INFLAMMATION A: Clusters of large dyscohesive cells are present within a pleural biopsy. Necrosis is seen. B: A separate case shows large dyscohesive cells within f... More

PLEURAL METASTASIS Figure 7-8 PLEURAL METASTASIS The pleura is infiltrated by metastatic small cell carcinoma. More

PLEURAL METASTASIS Figure 7-9 PLEURAL METASTASIS The pleura is infiltrated by metastatic squamous cell carcinoma. More

MESOTHELIAL CELLS: ULTRASTRUCTURE Figure 1-2 MESOTHELIAL CELLS: ULTRASTRUCTURE A,B: Mesothelial cells form a single sheet on the surface of the serosal membranes (A), with microvilli projecting from the surface (B). C: Cells are connected by abundant junctional complexes and desmosomes. (Courtes... More

EPITHELIOID MESOTHELIOMA:WITH SIGNET RING CELLS Figure 3-38 EPITHELIOID MESOTHELIOMA:WITH SIGNET RING CELLS The tumor cells have a clear intracytoplasmic vacuole, giving them a signet ring cell appearance. This pattern puts signet ring cell carcinoma in the differential diagnosis. More

MESOTHELIAL CELLS: ULTRASTRUCTURE Figure 1-3 MESOTHELIAL CELLS: ULTRASTRUCTURE A scanning electron microscopic view of visceral rat pleura shows the profusion of microvilli on the surface. More

EPITHELIOID MESOTHELIOMA Figure 3-17 EPITHELIOID MESOTHELIOMA Infiltrating tumor cells are compressed between collagen fibers making it difficult to differentiate from sarcomatoid morphology. More

EPITHELIOID MESOTHELIOMA: TRABECULAR PATTERN Figure 3-28 EPITHELIOID MESOTHELIOMA: TRABECULAR PATTERN The tumor cells form thick cords invading loose fibromyxoid stroma. More