Incidental mesonephric remnant hyperplasia of the jejunal mesentery: A diagnostic challenge

Our plain-English summary of Incidental mesonephric remnant hyperplasia of the jejunal mesentery: A diagnostic challenge, by J.F. Val-Bernal, M.M. Mayorga, A.K. Calapaquí-Terán, et al (Pathology, Research and Practice, 2021).

The study

• Authors: J.F. Val-Bernal, M.M. Mayorga, A.K. Calapaquí-Terán, E. Toledo
• Journal: Pathology, Research and Practice
• Published: 2021;220:153388
• Type of article: Case report
• Cited by: 1 article, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Mesonephric remnants are embryonic vestiges of the mesonephric (Wolffian) ducts which regress during normal development. These remnants have been uncommonly reported in the female and male reproductive tract as a spectrum of morphologic lesions that can be misdiagnosed as carcinoma. One case of mesonephric remnant hyperplasia of the jejunal mesentery incidentally found in a 47-year-old man is herein reported. This is the first description of mesonephric hyperplasia arisen in the mesentery. The presence of ducts, tubules, and cysts lined by bland, epithelial, cuboidal cells with scant cytoplasm, and diffuse pseudoinfiltrative growth pattern can raise the possibility of neoplasia. Immunohistochemically, mesonephric epithelia have a characteristic staining. CD10 highlights the apical-luminal aspect of the cells. Besides, intense reactivity is showed for high-molecular-weight cytokeratin (CK), CK7, bcl2, and vimentin. The main differential diagnosis includes mesothelial hyperplasia, epithelial mesothelioma, well-differentiated neuroendocrine tumor, and infiltration due to acinar adenocarcinoma of the prostate. However, a detailed microscopic study with the aid of immunohistochemistry helps separate mesonephric remnants from malignant processes. The mesonephric hyperplasia of the mesentery we have reported adds to the spectrum of mesonephric remnants a new location. Familiarity with this lesion is indispensable to avoid overdiagnosis.

Copyright © 2021 Elsevier GmbH. All rights reserved.

In plain English

This case report described one 47-year-old man treated at the authors' hospital in Santander, Spain, for severe bleeding from the small intestine. The article does not mention asbestos. Epithelial mesothelioma appears only as one of the conditions the authors said must be told apart from this lesion. Surgeons removed two damaged segments of the jejunum, 2.5 cm and 11 cm long, and the patient was discharged on the 12th day after surgery. When the tissue was examined under the microscope, the pathologists found by chance a 17 mm growth of small ducts and tubules in the mesentery beside the jejunum. The cells showed no significant atypia and no mitotic figures. Stains were strongly positive for CD10, high-molecular-weight cytokeratin, CK7, bcl2 and vimentin. They were negative for markers including WT1 gene product, chromogranin A, synaptophysin and prostate markers. The authors classified the growth as diffuse mesonephric hyperplasia, which arises from leftover embryonic tissue. They concluded that, to their knowledge, this was the first description of it in the mesentery, and that its growth pattern can make a tumor seem likely.

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 patient)
• Who was studied: one 47-year-old man with gastrointestinal bleeding, treated at Marqués de Valdecilla University Hospital, Santander, Spain; date of treatment not given
• Main results:
  • Two devitalized jejunal segments were removed, measuring 2.5 cm and 11 cm in length
  • The patient recovered and was discharged on the 12th postoperative day
  • An incidental proliferation of ducts and tubules was found in the mesenteric border of the jejunum
  • The lining cells showed no significant atypia, no mitotic figures and no nuclear hyperchromasia
  • The lesion measured 17 mm in greatest dimension
  • Immunohistochemistry showed intense, diffuse staining for high-molecular-weight cytokeratin (34βE12), CK7, bcl2 and vimentin, in addition to strong apical-luminal CD10 staining
  • The lesion was negative for markers including WT1 gene product, chromogranin A, synaptophysin, PSA, PAP and NKX3.1; Ki67 was also negative
  • The authors classified the lesion as diffuse mesonephric hyperplasia
  • The authors listed epithelial mesothelioma among the conditions to be distinguished from this lesion
• The authors' conclusion: The authors concluded that this is the first description of mesonephric hyperplasia in the mesentery, and that its ducts and tubules with a diffuse, pseudoinfiltrative growth pattern can raise the likelihood of neoplasia

Topics

Medical terms in this study, explained in our Lexicon: Mesentery, Carcinoma, Tubule, Differential Diagnosis, Reactive Mesothelial Hyperplasia, Mesothelioma, Well-Differentiated, Acinar.

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