Fine-needle aspiration of a well-differentiated papillary mesothelioma in the inguinal hernia sac: A case report and review of literature

Our plain-English summary of Fine-needle aspiration of a well-differentiated papillary mesothelioma in the inguinal hernia sac: A case report and review of literature, by Y.Y. Wheeler, F. Burroughs, Q.K. Li (Diagnostic Cytopathology, 2009).

The study

• Authors: Y.Y. Wheeler, F. Burroughs, Q.K. Li
• Journal: Diagnostic Cytopathology
• Published: 2009;37(10):748-54
• Type of article: Case report, Review
• Cited by: 11 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Well-differentiated papillary mesothelioma (WDPM) is an uncommon subtype of epithelioid mesothelioma. In contrast to malignant epithelioid mesothelioma, WDPM has a low malignant potential and an indolent clinical course. WDPM may be difficult to diagnose and differentiate from benign reactive mesothelial cells and other malignant neoplasm on cytology specimens due to the presence of papillary or tubulopapillary clusters of tumor cells. We report a case of a 63-year-old Asian male with a slowly growing left inguinal hernia mass for several years and a concurrent 8 cm mass in the peritoneal wall. The cytology of ultrasound-guided fine-needle aspiration (FNA) of the left inguinal hernia and peritoneal masse reveal cellular specimens with numerous individual and tubulopapillary clusters of epithelioid mesothelial cells in a background of scant hyalinized material. Tumor cells show minimal cytological atypia. The differential diagnoses are broad and include reactive mesothelial cells, WDPM, and other malignant neoplasm. The follow-up surgical resection of masses reveals features of WDMP. It is important to recognize this entity in the differential diagnosis, because the clinical management of WDPM is quite different from that of malignant neoplasm. On the basis of the published data in the literature, it suggests that in male patients, the WDPM occurs predominantly in pleural cavity of older men in their 50s, and about half of the patients have history of asbestos exposure. However, the data is limited and insufficient for a definitive conclusion.

(c) 2009 Wiley-Liss, Inc.

In plain English

This article was a case report combined with a review of published cases. It described a 63-year-old Asian man at The Johns Hopkins Hospital with well-differentiated papillary mesothelioma (WDPM), a rare subtype of epithelioid mesothelioma, found in a left inguinal hernia sac and in the anterior peritoneal wall. The hernia had slowly grown over 7 years, and no history of asbestos exposure was found. Fine-needle aspiration of both masses showed tumor cells in tubulopapillary clusters with no mitotic figures. Surgery showed no stromal invasion. The tumor cells were strongly positive for calretinin, and fewer than 5% were Ki-67 positive. He had received no further treatment for 13 months after surgery. The authors described it as the third reported fine-needle aspiration case of WDPM. In the literature they found 38 cases in men, aged 18 to 84 (mean 55.8 years), 15 (39.5%) of them in the pleural space. The authors said WDPM in men seems to occur mainly in the pleural cavity of men in their 50s, about half with asbestos exposure, but that the data were insufficient for a definitive conclusion.

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 with a review of the literature on WDPM in male patients
• Who was studied: One 63-year-old Asian man referred to The Johns Hopkins Hospital with a left inguinal hernia mass, later also found to have an anterior peritoneal wall mass; plus 38 previously reported WDPM cases in men from the literature
• Exposure: No history of asbestos exposure was found in the patient; the literature review recorded asbestos exposure where reported
• Main results:
  • The patient's left inguinal hernia developed after surgical repair of a left groin hydrocele and slowly increased in size over 7 years
  • A CT scan showed a thickened area of about 8 cm at the anterior peritoneal wall and a moderate amount of ascites
  • On fine-needle aspiration smears, no mitotic figures were seen in the tumor cell fragments
  • In the surgically removed hernia sac and peritoneal wall masses, no stromal invasion, stromal hypercellularity or tumor necrosis was found
  • The patient's tumor cells were strongly positive for calretinin, occasionally positive for EMA, and negative for Ber-EP4, mCEA, CD15, desmin and mucicarmine
  • Ki-67 staining of the patient's tumor showed low proliferation activity, with fewer than 5% of tumor cells positive
  • After surgery the patient recovered well and had received no further treatment for 13 months to date
  • The authors stated that this was the third case report of fine-needle aspiration findings of WDPM
  • The literature review found 38 WDPM cases in male patients, about one fourth of all WDPM cases
  • Among the 38 male cases, ages ranged from 18 to 84 years, with a mean of 55.8 years
  • Among the male cases, tumor locations were pleural space (39.5%, 15 cases), omentum (21.1%, 8 cases), peritoneal cavity (13.2%, 5 cases), tunica vaginalis (10.5%, 4 cases), and others
  • In the reviewed male cases, 13 patients had surgical resection and 9 had no treatment
  • From the review, the authors stated that WDPM in men seems to occur mainly in the pleural cavity of men in their 50s, and that about half have a history of asbestos exposure
• The authors' conclusion: The authors concluded that WDPM's rarity and its resemblance to other benign or malignant lesions can make diagnosis difficult, especially on cytology specimens. They said it is important to recognize WDPM because its clinical management differs from that of malignant neoplasm.
• Limitations the authors state:
  • The authors stated that the data on male patients are insufficient for a definitive conclusion
  • Follow-up data in the reviewed cases were incomplete
  • Tumor size was reported in only some of the reviewed cases
  • The authors cautioned that none of the immunohistochemical markers has 100% specificity

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma, Peritoneal mesothelioma.

Medical terms in this study, explained in our Lexicon: Fine-Needle Aspiration, Well-Differentiated Papillary Mesothelioma, Inguinal Hernia, Epithelioid, Mesothelioma, Reactive Mesothelial Cells, Neoplasm, Cytology.

Related studies

• Fine needle aspiration cytology of well-differentiated papillary mesothelioma: a case report — Y. Gong, R. Ren, et al. (2005)
• Well-differentiated papillary mesothelioma of the peritoneum: a diagnostic dilemma on fine-needle aspiration cytology — J.G. Nasit, G. Dhruva (2014)
• Malignant biphasic peritoneal mesothelioma in a child: fine-needle aspiration cytology, histopathology, and immunohistochemical features along with review of literature — S.K. Arora, R. Srinivasan, et al. (2012)
• Peritoneal mesothelioma masquerading as an inguinal hernia — S. Chakravartty, J.C. Singh, et al. (2011)
• Peritoneal mesothelioma masquerading as an inguinal hernia — S. Chakravartty, J.C. Singh, et al. (2012)
• Incarcerated inguinal hernia from metastatic pleural mesothelioma: PET/CT imaging — V.X. Nguyen, B.D. Nguyen, et al. (2012)

Browse more research in Diagnostic Cytopathology, or return to medical research.