Fine-needle aspiration biopsy and intraoperative cytologic smear findings in a case of benign mesothelial-cell inclusions involving a lymph node: case report and review of the literature.

Although first described over a decade ago, the rare entity of mesothelial lymph node inclusions (nonneoplastic mesothelial cells involving lymph node sinuses) is not well-known among pathologists. Unlike most lymph node inclusions such as Müllerian inclusions or nevus cells, which usually occur in the capsule of the lymph node, mesothelial cells involve the lymph node sinus, mimicking metastatic carcinoma or metastatic mesothelioma. The spectrum of histologic findings ranges from a few mesothelial cells, perhaps only detectable by immunohistochemical stains, to a massive distention of the lymph node sinus with abundant mesothelial cells. Mesothelial-cell inclusions in lymph nodes are usually found in mediastinal lymph nodes of patients with pleural and/or pericardial effusions. It is hypothesized that the effusion, due to whatever cause, allows for mesothelial-cell migration into the submesothelial lymphatics and regional lymph nodes. To our knowledge, cytologic findings on aspiration biopsy and intraoperative smear preparations of a lymph node with mesothelial-cell inclusions have never been described. Familiarity with this entity is important in preventing misdiagnosis of malignancy.

Type specific persistence of high risk human papillomavirus (HPV) as indicator of high grade cervical squamous intraepithelial lesions in young women: population based prospective follow up study.

OBJECTIVES: To investigate the role of human papillomavirus (HPV) in the development of cervical neoplasia in women with no previous cervical cytological abnormalities; whether the presence of virus DNA predicts development of squamous intraepithelial lesion; and whether the risk of incident squamous intraepithelial lesions differs with repeated detection of the same HPV type versus repeated detection of different types. DESIGN: Population based prospective cohort study. SETTING: General population in Copenhagen, Denmark. PARTICIPANTS: 10 758 women aged 20-29 years followed up for development of cervical cytological abnormalities; 370 incident cases were detected (40 with atypical squamous cells of undetermined significance, 165 with low grade squamous intraepithelial lesions, 165 with high grade squamous intraepithelial lesions). MAIN OUTCOME MEASURES: RESULTS of cervical smear tests and cervical swabs at enrollment and at the second examination about two years later. RESULTS: Compared with women who were negative for human papillomavirus at enrollment, those with positive results had a significantly increased risk at follow up of having atypical cells (odds ratio 3.2, 95% confidence interval 1.3 to 7.9), low grade lesions (7.5, 4.8 to 11.7), or high grade lesions (25.8, 15.3 to 43.6). Similarly, women who were positive for HPV at the second examination had a strongly increased risk of low (34.3, 17.6 to 67.0) and high grade lesions (60.7, 25.5 to 144.0). For high grade lesions the risk was strongly increased if the same virus type was present at both examinations (813.0, 168.2 to 3229.2). CONCLUSIONS: Infection with human papillomavirus precedes the development of low and high grade squamous intraepithelial lesions. For high grade lesions the risk is greatest in women positive for the same type of HPV on repeated testing.