Pulmonary tumor thrombotic microangiopathy: Exploration into current diagnostic aids and therapeutics

Figures

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  Figure 1. Numerous foci of relatively bland, monotonous cells with large central mucin droplets and eccentric nuclei are seen invading lymphatic spaces and small pulmonary vessels (black arrows). The tumor cells are predominantly found within perivascular lymphatic spaces (a, hematoxylin and eosin [H&E], ×20). However, tumor emboli are also seen occluding small pulmonary vessels (b, H&E, ×100; C, H&E, ×200) and pankeratin immunostaining highlights multiple tumor emboli within pulmonary vessels (D, AE1/AE3, ×100). Tumor metastases are often associated with organizing thromboses within numerous pulmonary vessels (black arrowhead), although individual tumor cells within these thrombi are difficult to discern. Foci of tumor are also often seen in conjunction with areas of infarction and hemorrhage (black stars), as well as hyaline membrane formation/diffuse alveolar damage (best appreciated within the alveolar spaces on the right in c).

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  Figure 2. Postmortem pneumonectomy specimens demonstrating numerous tumor emboli within the pulmonary vasculature (black arrows). Foci of pleomorphic, cohesive cells with large irregular nuclei and conspicuous nucleoli are seen infiltrating and occluding larger blood vessels (a1, hematoxylin and eosin [H&E], ×100; a2, ×200 magnification of tumor emboli in a1; and (c), H&E, ×200) and small pulmonary vessels, including those within peribronchovascular lymphatic spaces (b, H&E, ×200). Also seen within the lung parenchyma are areas of pulmonary edema (black arrowheads) as well as hemorrhage within the alveoli and airways (black stars).