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Smooth muscle tumours presenting as pleural neoplasms
Author(s) -
MORAN C.A.,
SUSTER S.,
KOSS M.N.
Publication year - 1995
Publication title -
histopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.626
H-Index - 124
eISSN - 1365-2559
pISSN - 0309-0167
DOI - 10.1111/j.1365-2559.1995.tb00214.x
Subject(s) - pleomorphism (cytology) , desmin , pathology , medicine , eosinophilic , mesothelioma , asymptomatic , immunohistochemistry , anatomy , vimentin
Five smooth muscle tumours presenting as pleural neoplasms are presented. The patients were three women and two men aged between 21 and 69 years (mean = 45 years). Clinically, one patient presented with chest pain, one with empyema and the other three were asymptomatic. Two of the tumours were located in the left side of the chest cavity and three in the right side. In four cases, the lesions presented as solitary pleural‐based masses that varied in size from 10–18 cm in greatest dimension; in two of these cases, involvement of the diaphragm was present in addition to the pleural involvement. In one case, the tumour was seen to totally encase the right lung simulating the growth pattern of malignant mesothelioma. Histologically, three cases displayed an atypical spindle cell proliferation with marked cellular pleomorphism, mitoses and areas of hemorrhage and necrosis. The other two cases were characterized by a bland‐appearing smooth muscle proliferation of uncertain malignant potential composed of elongated cells with a moderate amount of eosinophilic cytoplasm and cigar‐shaped nuclei, lacking significant nuclear pleomorphism or mitotic activity. Immunohistochemical studies showed strong positivity for alpha‐smooth muscle actin in all cases, and for desmin in four of five cases, and a focal positive reaction for keratin in one case. Ultrastructural examination in one of the high‐grade tumours showed features of smooth muscle differentiation. Three of the patients were treated by complete surgical excision while, in the other two patients, the lesions were incompletely resected. Follow‐up ranging from 2–12 months has not shown evidence of recurrence in those patients with complete surgical resection, or metastasis in any of the patients. These cases appear to represent a previously undescribed form of primary pleural neoplasm. Because of the differences in biological behaviour compared with other types of pleural neoplasms, smooth muscle tumours should be included in the differential diagnosis of primary spindle cell tumours of the pleura.