Maurizio Pinamonti

MMP-7 is a highly specific negative marker for benign and malignant mesothelial cells in serous effusions ☆

The aim of this study was to analyze the diagnostic role of MMP-7 in effusion cytology. Effusions (n = 356), consisting of 307 carcinomas (184 ovarian, 55 breast, 32 lung, 36 carcinomas of other origin) and 49 malignant mesotheliomas, were analyzed for MMP-7 expression using immunohistochemistry. MMP-7 was expressed in 124/307 (40%) carcinomas and was uniformly absent in malignant mesotheliomas (0/49; 0%; P < .001). Reactive mesothelial cells were similarly MMP-7 negative in all carcinoma specimens. In carcinomas, expression was most frequent in tumors of ovarian and other female genital (cervical and endometrial) origin (P < .001). The sensitivity and specificity of this marker in the differential diagnosis between high-grade serous carcinoma and malignant mesothelioma were 46% and 100%, respectively. In conclusion, MMP-7 expression is highly specific, though only of moderate sensitivity, for the diagnosis of carcinoma in the differential diagnosis from both benign and malignant mesothelial cells.

The diagnostic role of PTEN and ARID1A in serous effusions

The aim of this study was to analyze the diagnostic role of PTEN and ARID1A in effusion cytology. Effusions (n = 279), consisting of 226 carcinomas (70 ovarian, 64 breast, 36 lung, and 15 uterine corpus carcinomas; 41 carcinomas of other origin) and 53 malignant mesotheliomas, were analyzed for PTEN and ARID1A expression using immunohistochemistry. PTEN was preserved in 166 (59%) tumors, partially lost in 38 (14%), and absent in 75 (27%), with lower expression in malignant mesotheliomas compared to carcinomas, though not significantly (p = 0.084). ARID1A was preserved in 243 (88%) tumors, partially lost in 18 (6%), and absent in 18 (6%). The majority of tumors with absent ARID1A were ovarian carcinomas, predominantly of clear cell or low-grade serous type. Reactive mesothelial cells in carcinoma specimens were uniformly positive for both proteins. ARID1A mutation analysis showed no mutations in eight analyzed specimens negative by immunohistochemistry. Loss of PTEN and ARID1A expression is highly specific for malignancy in effusion pathology. Loss of PTEN is not informative of organ of origin, whereas absence of ARID1A should raise suspicion of an ovarian primary.

The diagnostic role of BAP1 in serous effusions

The aim of this study was to analyze the diagnostic role of BAP1 in effusion cytology. Effusions (n = 258), consisting of 53 malignant mesotheliomas and 205 other cancers, the majority carcinomas (62 breast, 60 ovarian, 31 lung, 51 carcinomas of other origin, 1 melanoma), were analyzed for BAP1 expression using immunohistochemistry. BAP1 was lost in 46 (87%) mesotheliomas compared with 4 (2%) of 205 other cancers (P < .001), resulting in sensitivity and specificity of 87% and 98%, respectively. There was no significant difference between peritoneal (n = 14) and pleural (n = 39) mesotheliomas. The 4 carcinomas with loss of BAP1 included 1 ovarian, 1 breast, 1 uterine cervical, and 1 gastric carcinoma. The present study supports the role of BAP1 as a highly sensitive and specific marker for malignant mesothelioma in serous effusions and argues for inclusion of this test in all specimens in which this diagnosis is considered.

Breast Cytopathology Assessing the Value of FNAC in the Diagnosis of Breast Lesions

Breast cytopathology is a field characterized by practicality and diagnostic efficacy. This book focuses mainly on morphology, with helpful hints for recognizing benign lesions and the main features of malignancy. It reviews specific features of various lesions and the consequences of the diagnosis for the management of the patient. Each chapter contains high-quality cytology images accompanying the descriptions, including comparison images to distinguish the most important morphological features and to help in the differential diagnosis. Fine needle aspiration cytology (FNAC) sampling and preparation technique, fixation, staining, and principles of its interpretation are covered. Immunocytochemistry and ancillary techniques are outlined, as well as the main clinical and radiological features of breast lesions, and the cytological diagnostics of axillary lymph nodes. This publication will be of great use to medical practitioners in their first approach to breast cytopathology, as well as to pathologists and cytotechnicians with little to moderate experience in the field.