Pulmonary pleomorphic large-cell γδ T-cell lymphoma (case no. 4). (A) Atypical lymphoid cells involve the bronchiolar wall and epithelium; (B) features of angioinvasion; note the preservation of alveolar structures (lung biopsy specimen with hematoxylin-eosin stain); (C) neoplastic cells strongly express TCR γδ. (Immunohistochemical staining on frozen sections with anti-δTCR1 antibody, APAAP technique.)