title: Mesothelial cell inclusions in pelvic and para-aortic lymph nodes: a clinicopathologic analysis.
abstract: Benign lymph node inclusions are commonly encountered during surgery for gynecologic neoplasms and are potential mimics of metastatic tumor. The presence of mesothelial cell inclusions in pelvic lymph nodes is extremely rare. We report the clinicopathologic features of 10 patients with ovarian tumors and mesothelial cell inclusions detected in the sinuses of pelvic and paraaortic lymph nodes. All patients had concurrent massive ascites and mesothelial cell hyperplasia at the time of lymph node dissection. Histologically, nodal mesothelial cells were identified predominantly within the subcapsular, trabecular and medullary sinuses. Moreover, intra- and extranodal lymphatics also contained mesothelial cells, confirming their mode of lymphatic transport to nodal sinuses. This finding, together with mesothelial cell hyperplasia and massive ascites suggest that mesothelial cells derive from reactive serosal mesothelium and are dislodged into draining lymphatics. This study indicated the pathogenic significance of the lymphatic transport mechanism. Nodal mesothelial cell inclusions should be distinguished from metastatic tumor to avoid inaccurate staging in a patient with a known tumor or the false negative diagnosis of an occult primary tumor. Recognition of this entity by immunohistochemical evaluation in addition to routinely stained sections is important to prevent a diagnosis of metastatic carcinoma or malignant mesothelioma.
authors.affiliation: Department of Pathology, Severance Hospital, Yonsei University College of Medicine Seoul, Republic of Korea.
authors.forename: Hyun-Soo
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Gynecology and Obstetrics, Pusan National University Yangsan Hospital, Pusan National University School of Medicine Yangsan, Republic of Korea.
authors.forename: Gun
authors.initials: G
authors.lastname: Yoon
authors.affiliation: Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine Seoul, Republic of Korea.
authors.forename: Yoo-Young
authors.initials: YY
authors.lastname: Lee
authors.affiliation: Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine Seoul, Republic of Korea.
authors.forename: Tae-Joong
authors.initials: TJ
authors.lastname: Kim
authors.affiliation: Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine Seoul, Republic of Korea.
authors.forename: Chel-Hun
authors.initials: CH
authors.lastname: Choi
authors.affiliation: Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine Seoul, Republic of Korea.
authors.forename: Jeong-Won
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine Seoul, Republic of Korea.
authors.forename: Byoung-Gie
authors.initials: BG
authors.lastname: Kim
authors.affiliation: Department of Obstetrics and Gynecology, Samsung Medical Center, Sungkyunkwan University School of Medicine Seoul, Republic of Korea.
authors.forename: Duk-Soo
authors.initials: DS
authors.lastname: Bae
authors.affiliation: Department of Pathology and Translational Genomics, Samsung Medical Center, Sungkyunkwan University School of Medicine Seoul, Republic of Korea.
authors.forename: Sang Yong
authors.initials: SY
authors.lastname: Song
mesh_terms: D000328:Adult; D000368:Aged; D001201:Ascites / Q000473:pathology; D014408:Biomarkers, Tumor / Q000032:analysis; D001706:Biopsy; D003937:Diagnosis, Differential; D004847:Epithelial Cells / Q000473:pathology*; D005260:Female; D006801:Humans; D006965:Hyperplasia; D007150:Immunohistochemistry; D002479:Inclusion Bodies / Q000737:chemistry / Q000473:pathology*; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009367:Neoplasm Staging; D010051:Ovarian Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D011237:Predictive Value of Tests; D014057:Tomography, X-Ray Computed
chemical_list: D014408:Biomarkers, Tumor
keywords: Mesothelial cell; ascites; inclusion; lymph node; metastatic carcinoma