EPITHELIOID MESOTHELIOMA: PAPILLARY PATTERN Figure 3-25 EPITHELIOID MESOTHELIOMA: PAPILLARY PATTERN Complex branching pattern is present at the top and more solid growth is seen at the bottom. More

EPITHELIOID MESOTHELIOMA:TUBULOPAPILLARY PATTERN Figure 3-24 EPITHELIOID MESOTHELIOMA:TUBULOPAPILLARY PATTERN The tumor forms tubular structures and spaces into which project papillae with fibrovascular cores. Benign-appearing mesothelium is seen at the bottom. More

EPITHELIOID MESOTHELIOMA: PAPILLARY PATTERN Figure 3-26 EPITHELIOID MESOTHELIOMA: PAPILLARY PATTERN The papillae are covered by single to multiple layers of tumor cells. More

EPITHELIOID MESOTHELIOMA: SOLID PATTERN Figure 3-27 EPITHELIOID MESOTHELIOMA: SOLID PATTERN There are sheets of epithelioid tumor cells with pale cytoplasm, round to oval nuclei, small to medium-sized nucleoli, and numerous mitotic figures. An area of necrosis is seen at lower left. More

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

EPITHELIOID MESOTHELIOMA:ADENOMATOID (ACINAR)/MICROCYSTIC PATTERN Figure 3-29 EPITHELIOID MESOTHELIOMA:ADENOMATOID (ACINAR)/MICROCYSTIC PATTERN There are gland-like structures formed by bland mesothelial cells, infiltrating fibrous tissue. More

EPITHELIOID MESOTHELIOMA:MICROPAPILLARY AND PAPILLARY PATTERN Figure 3-35 EPITHELIOID MESOTHELIOMA:MICROPAPILLARY AND PAPILLARY PATTERN The tumor cells form multiple small papillae, most of which do not have fibrovascular cores, while others do. Mixed patterns are common. More

EPITHELIOID MESOTHELIOMA:MICROPAPILLARY PATTERN Figure 3-36 EPITHELIOID MESOTHELIOMA:MICROPAPILLARY PATTERN The tumor forms micropapillary projections into spaces within the stroma. The tumor cells in this case are pleomorphic, with tumor giant cells and prominent nucleoli. More

EPITHELIOID MESOTHELIOMA:MICROPAPILLARY PATTERN Figure 3-37 EPITHELIOID MESOTHELIOMA:MICROPAPILLARY PATTERN Micropapillary clusters of mesothelioma cells are seen within dilated lymphatics. More

EPITHELIOID MESOTHELIOMA Figure 3-21 EPITHELIOID MESOTHELIOMA Left: Multiple patterns are present in this epithelioid mesothelioma, including trabecular, single cell, and adenomatoid/microcystic. The stroma is notably myxoid. Right: In this case, there are areas showing papillary and adenomatoid... More

EPITHELIOID MESOTHELIOMA Figure 3-23 EPITHELIOID MESOTHELIOMA Psammoma bodies are present in this pleural mesothelioma with papillary pattern. More

EPITHELIOID MESOTHELIOMA Figure 3-49 EPITHELIOID MESOTHELIOMA The tumor is infiltrating the lung with a desquamative interstitial pneumonia (DIP)-like pattern. More

THORACOLITH Figure 8-7 THORACOLITH A smooth, partly calcified nodule was removed from the pleural cavity, which showed the characteristic fibrous pattern of a pleural plaque. More

PLEURAL PLAQUE Figure 8-6 PLEURAL PLAQUE Left: A sharply demarcated, hard, almost waxy plaque lies on the parietal pleural surface. Right: The fibrosis shows a lamellar “basket-weave” pattern. More

EPITHELIOID MESOTHELIOMA:ADENOMATOID (ACINAR)/MICROCYSTIC Figure 3-34 EPITHELIOID MESOTHELIOMA:ADENOMATOID (ACINAR)/MICROCYSTIC The tumor cells have very low-grade morphology and show a cribriform pattern mixed with solid nests, reminiscent of adenoid cystic carcinoma. 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

EPITHELIOID MESOTHELIOMA:NUCLEAR ATYPIA SCORE 3 Figure 3-52 EPITHELIOID MESOTHELIOMA:NUCLEAR ATYPIA SCORE 3 The tumor nuclei are more atypical than those seen in grade 2, with markedly enlarged nucleoli, but are not as pleomorphic as is seen in the pleomorphic pattern of epithelioid mesothelioma.... More

EPITHELIOID MESOTHELIOMA Figure 3-71 EPITHELIOID MESOTHELIOMA A: There is strong diffuse staining with antibody to calretinin. Most tumor cells have the typical pattern of staining of stronger nuclear and weaker cytoplasmic staining. B: There is strong nuclear staining with antibody to WT-1 in t... More