Signet-ring cell appearance of atrophic fat cells

Our plain-English summary of Signet-ring cell appearance of atrophic fat cells, by J.D. Gilbert, N.E.I. Langlois, A. Ruszkiewicz, et al (Forensic Science, Medicine, and Pathology, 2021).

The study

• Authors: J.D. Gilbert, N.E.I. Langlois, A. Ruszkiewicz, D. Moffat, K. Cash
• Journal: Forensic Science, Medicine, and Pathology
• Published: 2021;17(1):141-143
• Type of article: Case report
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Cells with 'signet-ring' appearance were found at post-mortem examination of a man with a history of chronic illness, weight loss and multiple regions of 'bowel thickening' during life. Due to the decedent's history, the finding raised the possibility of disseminated signet-ring adenocarcinoma. However, the vacuoles did not stain for mucin and the cells did not stain for keratin. The cells did stain for calretinin and so a diagnosis of signet ring mesothelioma was considered. However, it was suggested that the cells with a cytoplasmic vacuole displacing the nucleus to one side producing the signet-ring appearance were instead atrophic fat cells. This was subsequently proven by Oil Red O staining.

In plain English

This was a case report about the autopsy of one 58-year-old man. During life he had mixed connective tissue overlap syndrome (SLE and scleroderma) with interstitial lung disease, had lost weight, and had areas of bowel thickening. The article does not mention asbestos exposure. At autopsy, cells with a 'signet-ring' look, where a bubble in the cell pushes the nucleus to one side, were found in the epicardium, subcutaneous fat, visceral pleura and small intestine mesentery. Because of his history, a spreading signet-ring adenocarcinoma was considered first. The cells did not stain for mucin or keratins, which the authors regarded as excluding carcinoma. The cells did stain for calretinin, and the pleura showed focal white thickening, so signet-ring mesothelioma was considered. The cells also stained for S-100 protein. A fat stain (Oil Red O) showed that the bubbles contained fat, confirming the cells were fat cells, so mesothelioma was not the final diagnosis. The authors concluded that malnutrition and weight loss had shrunk the fat cells so that they mimicked signet-ring cancer cells. Death was attributed to bronchopneumonia complicating chronic interstitial lung disease.

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: case report (single autopsy case)
• Who was studied: one 58-year-old man examined at post-mortem; no location or date of the case is stated in the text
• Exposure: No asbestos or other fiber exposure is reported. The background illness was mixed connective tissue overlap syndrome (SLE and scleroderma) with interstitial lung disease and weight loss.
• Main results:
  • Cells with a signet-ring appearance were found throughout the epicardium, subcutaneous fat, visceral pleura and small intestine mesentery of this man
  • The cell vacuoles did not stain with Alcian blue or Periodic-acid Schiff, and the cells did not stain for keratins (AE1/AE3, CK20, CK19). The authors regarded this as excluding carcinoma.
  • The cells stained for calretinin and later for S-100 protein
  • Because of the calretinin staining and focal white thickening of the pleura, signet-ring mesothelioma was considered
  • Oil Red O staining of frozen sections showed the vacuoles contained fat, confirming the cells were fat cells (adipocytes)
  • Death was attributed to bronchopneumonia complicating chronic interstitial lung disease in a man with mixed connective tissue disease
• The authors' conclusion: The authors concluded that malnutrition and weight loss secondary to mixed connective tissue disease caused fat atrophy with signet-ring-like change of fat cells. They stated that the case highlights the potential for diagnostic error, because this appearance can mimic metastatic signet-ring carcinoma.

Topics

Medical terms in this study, explained in our Lexicon: Autopsy, Adenocarcinoma, Calretinin, Mesothelioma.

Related studies

• Mesothelioma with signet-ring cell features: report of 23 cases — N.G. Ordóñez (2013)
• Signet ring cell mesothelioma; A diagnostic challenge — H. Wang, C. Herath (2019)
• "Signet-ring" cells--a caveat in the diagnosis of a diffuse peritoneal mesothelioma occurring in a lady presenting with recurrent ascites: an unusual case report — B. Rekhi, S. Pathuthara, et al. (2010)
• Pulmonary acantholytic squamous cell carcinoma with focal signet ring cell morphology mimicking malignant mesothelioma on fine needle aspiration cytology: a case report — S.E. Choi, H.S. Park (2016)
• Mesothelial cell differentiation into osteoblast- and adipocyte-like cells — S.M. Lansley, R.G. Searles, et al. (2011)
• Cancer-promoting role of adipocytes in asbestos-induced mesothelial carcinogenesis through dysregulated adipocytokine production — S.H. Chew, Y. Okazaki, et al. (2014)

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