Smooth muscle tumours of the pleura

Our plain-English summary of Smooth muscle tumours of the pleura, by C.A. Moran, S. Suster, M.N. Koss (Histopathology, 1997).

The study

• Authors: C.A. Moran, S. Suster, M.N. Koss
• Journal: Histopathology
• Published: 1997;30(1):97-8
• Type of article: Comment, Letter
• Cited by: 7 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Summary of the article

In this letter, Moran, Suster and Koss, of the Armed Forces Institute of Pathology in Washington DC, replied to a commentary by Dr A.R. Gibbs on their 1995 paper describing smooth muscle tumours presenting as pleural neoplasms. They stated that four tumours were large (10–18 cm), ill-defined masses and one was a diffuse tumour encasing the right lung in a fashion reminiscent of mesothelioma. None was well localized, encapsulated or polypoid. They argued against a diagnosis of localized (solitary) fibrous tumour for several reasons: the bulky, diffuse, infiltrative growth; the absence of sclerosis on extensive sampling; diffuse, strong actin and desmin positivity; and negative CD34 staining performed after publication. The letter says this staining was done in four cases but lists only cases 1, 3 and 5. They rejected Dr Gibbs's suggestion that case 4 was a 'leiomyoid' mesothelioma, because immunohistochemistry and electron microscopy showed no epithelial differentiation, and kept their diagnosis of leiomyosarcoma. They accepted that submesothelial cells can show smooth muscle differentiation. In a printed reply, Dr Gibbs considered the absence of CD34 their most convincing argument, while noting that not all solitary fibrous tumours express this antigen. He found the leiomyosarcoma classification less convincing, stating that sarcomatous mesotheliomas may lack epithelial features and that the authors' criteria would be too restrictive for diagnosing sarcomatous mesothelioma.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.

In plain English

This is a letter to the editor, not a new study. The authors replied to Dr Gibbs's commentary on their earlier paper on smooth muscle tumours presenting as pleural tumours. Four tumours were large (10 to 18 cm), ill-defined masses. The fifth was a diffuse tumour completely encasing the right lung in a way reminiscent of mesothelioma. In two cases the tumour also extended into the diaphragm. They gave several reasons against the alternative diagnosis of localized (solitary) fibrous tumour. Their tumours grew in a bulky, diffuse, infiltrative way, unlike that tumour's typical presentation. None of their cases showed the sclerosing areas typical of that tumour. Most tumour cells stained strongly for actin and desmin. CD34 stains done after publication were negative in all cases tested. They rejected the view that case 4 was a 'leiomyoid' mesothelioma, since no epithelial differentiation was found, and kept their diagnosis of leiomyosarcoma. The authors concluded that they preferred to label these tumours smooth muscle tumours. Which cells the tumours arose from remained, they wrote, a matter of speculation. The letter does not mention asbestos or exposure.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Letter to the editor (correspondence) replying to a commentary on the authors' earlier published case series; no new study was done
• Who was studied: Five pleural tumours from the authors' earlier paper: four large, ill-defined masses and one diffuse tumour. The letter gives no patient details, places or dates.
• Main results:
  • Four tumours were large (10 to 18 cm), ill-defined masses. One was a diffuse tumour completely encasing the right lung in a way reminiscent of mesothelioma.
  • In two cases the tumour extended beyond the pleura into the diaphragm.
  • The bulky, diffuse and infiltrative growth of the tumours was, the authors wrote, quite unlike the typical presentation of localized fibrous tumour.
  • None of the cases showed the sclerosing features typical of solitary fibrous tumours, even on extensive sampling.
  • Most tumour cells showed diffuse, strong staining for actin and desmin. The authors said this did not fit solitary fibrous tumour.
  • CD34 stains done after publication were negative in all cases tested. The letter says four cases but lists only cases 1, 3 and 5.
  • For case 4, no evidence of epithelial differentiation was found. The authors kept their diagnosis of leiomyosarcoma rather than 'leiomyoid' mesothelioma.
• The authors' conclusion: The authors preferred to label these tumours smooth muscle tumours. They said whether the tumours arose from smooth muscle precursors, uncommitted stem cells or submesothelial cells remains a matter of debate and speculation.

Topics

Medical terms in this study, explained in our Lexicon: Pleura, Pathology, Neoplasm, Mesothelioma, Desmin, CD34, Immunohistochemistry.

Related studies

• Smooth muscle tumours of the pleura — A.R. Gibbs (1995)
• Distribution of transforming growth factor-beta 1, fibronectin, and smooth muscle actin in asbestos-induced pulmonary fibrosis in rats — T.D. Perdue, A.R. Brody (1994)
• Epithelioid endometrial and endometrioid stromal tumors: a report of four cases emphasizing their distinction from epithelioid smooth muscle tumors and other oxyphilic uterine and extrauterine tumors — E. Oliva, P.B. Clement, et al. (2002)
• Localized fibrous tumours of the pleura: 15 new cases and review of the literature — M. Suter, S. Gebhard, et al. (1998)
• Synovial sarcoma of the pleura and its differentiation from other primary pleural tumours: a clinicopathological and immunohistochemical review of three cases — A.G. Nicholson, P. Goldstraw, et al. (1998)
• Patterns of chromosomal imbalances in benign solitary fibrous tumours of the pleura — M. Krismann, H. Adams, et al. (2000)

Browse more research in Histopathology, or return to medical research.