Adenomatoid Tumor of the Pericardium: A Case Report and Literature Review

Our plain-English summary of Adenomatoid Tumor of the Pericardium: A Case Report and Literature Review, by M.H. Abdelhammed, N.S. Ramani (Curēus, 2025).

The study

• Authors: M.H. Abdelhammed, N.S. Ramani
• Journal: Curēus
• Published: 2025;17(4):e81734
• Type of article: Case report
• Read it: PubMed · Publisher · Free full text

Abstract

Adenomatoid tumors (ATs) are rare benign neoplasms of mesothelial origin, commonly found in the genital tracts but occasionally reported in extragenital locations, including the thoracic cavity. We describe the second case of a pericardial AT in a 65-year-old male with multiple comorbidities, including end-stage renal disease, diabetes mellitus, and heart failure. A small pericardial nodule was incidentally discovered during coronary artery bypass graft surgery without any clinical evidence of pericardial thickening. Histopathologic evaluation showed a well-circumscribed nodule with solid nests of epithelioid to spindled cells with bland cytology within a fibrous stroma. Immunohistochemical analysis demonstrated strong and diffuse positivity for calretinin, D2-40, WT-1, and pan-cytokeratin, confirming mesothelial differentiation. Markers of epithelial origin like MOC-31 and BerEp4 were negative, excluding the possibility of carcinomas of unknown origin. BAP1 nuclear expression was retained, and fluorescence in situ hybridization (FISH) for p16 (CDKN2A) was negative for homozygous deletion, distinguishing the lesion from mesothelioma. Besides contributing to the limited body of knowledge on extragenital and thoracic ATs, this case adds to the limited number of reports on pericardial ATs, providing an understanding of the rare occurrence of these tumors arising from the pericardium.

Copyright © 2025, Abdelhammed et al.

In plain English

This article was a case report with a review of earlier reports. It described a 65-year-old man with hypertension, end-stage kidney disease, diabetes and heart failure who had triple coronary bypass surgery, during which a 1.3 cm nodule was found incidentally on the pericardium (the sac around the heart). Under the microscope the nodule showed bland cells, with no atypia and no dividing cells seen. The cells stained strongly for pan-cytokeratin, calretinin, WT-1 and D2-40, which the authors read as consistent with mesothelial differentiation. BAP1 staining was retained, and a FISH test found no homozygous deletion of p16 (CDKN2A). The authors used these findings to tell the lesion apart from mesothelioma. The diagnosis was adenomatoid tumor, which the authors described as a benign tumor of mesothelial origin. They called it the second reported pericardial case. The patient died four months later from his other illnesses. Among nine earlier patients with chest-cavity cases in their review, no recurrence was reported for the seven with that information. The authors said larger numbers are needed to confirm their observations. The article does not mention asbestos.

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 of one patient with a literature review of previously reported thoracic adenomatoid tumors
• Who was studied: One 65-year-old male patient with hypertension, end-stage renal disease, diabetes mellitus and heart failure, reported from Baylor College of Medicine, Houston, USA. The date of care is not given. The literature review covered nine patients from eight earlier studies of thoracic adenomatoid tumor.
• Exposure: No exposure was studied. The article does not report the patient's occupational history or any asbestos exposure.
• Main results:
  • In the patient, an incidental 1.3 cm pericardial nodule was found during coronary artery bypass graft surgery.
  • Under the microscope, the patient's nodule showed no infarction, necrosis, calcification, cystic changes, atypia or mitotic figures.
  • The tumor cells in the patient's nodule were strongly positive for pan-cytokeratin, calretinin, WT-1 and D2-40. The authors described this as consistent with mesothelial differentiation.
  • In the patient's nodule, BAP1 nuclear expression was retained. The authors described this as consistent with a benign process.
  • In the patient's nodule, FISH for p16 (CDKN2A) showed no homozygous deletion.
  • The patient's lesion was diagnosed as adenomatoid tumor on the basis of its appearance and staining pattern.
  • The patient died four months later from his other illnesses.
  • In the literature review, 7 of 9 earlier patients with thoracic adenomatoid tumor were female.
  • In the literature review, the authors stated that none of the reviewed thoracic cases showed recurrence during follow-up of 4 to 19 months.
  • The authors' Table 1 lists recurrence as not available for 2 of the 9 earlier patients (Umezu et al. and Isotalo et al.). No recurrence is listed for the other 7.
• The authors' conclusion: The authors concluded that this was the second reported pericardial adenomatoid tumor. They noted that both pericardial cases occurred in older men, which they said suggests a potential age-related predisposition. They also suggested a potential association between tumor size and location in the chest.
• Limitations the authors state:
  • The authors stated that, because these tumors are rare, a larger sample size is needed to confirm their observations.

Topics

Medical terms in this study, explained in our Lexicon: Adenomatoid Tumor, Pericardium, Neoplasm, Pericardial, Epithelioid, Cytology, Calretinin, Podoplanin (D2-40).

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