Daniela Reghellin

PEComas: the past, the present and the future

The perivascular epithelioid cell (PEC) is a cell type constantly present in a group of tumors called PEComas. PEC expresses myogenic and melanocytic markers, such as HMB45 and actin. Recently, recurrent chromosomal alterations have been demonstrated in PEC. At present, PEComa is a widely accepted entity. In the past 10 years, the use of this term has allowed to report and describe numerous cases permitting to start highlighting the biology of this group of lesions. PEComas are related to the genetic alterations of tuberous sclerosis complex (TSC), an autosomal dominant genetic disease due to losses of TSC1 (9q34) or TSC2 (16p13.3) genes which seem to have a role in the regulation of the Rheb/mTOR/p70S6K pathway. There are some open questions about PEComas regarding its histogenesis, the definition of epithelioid angiomyolipoma and the identification of the histological criteria of malignancy. An innovative therapeutic trial using rapamycin is under way for tumors occurring in TSC such as renal angiomyolipoma and lymphangioleiomyomatosis. Its success could provide the rationale for the use of the same drug in other lesions composed of PECs, especially in the malignant ones.

HER-2/neu assessment in breast cancer using the original FDA and new ASCO/CAP guideline recommendations: impact on selecting patients for herceptin therapy.

We evaluated HER-2/neu status in 100 consecutive ductal breast carcinomas by using the Food and Drug Administration (FDA) and American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) scoring systems. With the FDA system, scores were 3+ in 23.0%, 2+ in 25.0%, and 0 or 1+ in 52.0% of cases. With the ASCO/CAP system, scores were 3+ in 16.0%, 2+ in 34.0%, and 0 or 1+ in 50.0%. With the FDA and ASCO/CAP systems, respectively, 3+ cases (n = 23 and 16, respectively) showed high-grade, granular HER-2/neu amplification in 15 (65%) and 14 (88%); low-grade, borderline amplification in 7 (30%) and 1 (6%); and chromosome 17 polysomy without amplification in 1 (4%) and 1 (6%). Concordance between schemes was higher for cases with high-grade, granular HER-2/neu amplification (concordance coefficient, 0.74). Cases with low-grade, borderline HER-2/neu amplification showed poor concordance (concordance coefficient, 0.20). The FDA and ASCO/CAP schemes for HER-2/neu evaluation select patients differently for trastuzumab therapy. Major discordance is present for low-grade, borderline HER-2/neu amplification. FDA low-grade, borderline tumors would be reclassified as without HER-2/neu amplification or as polysomic. The ASCO/CAP scheme has a great concordance coefficient between strong 3+ immunohistochemical cases and cases with high-grade, granular HER-2/neu amplification.

Perivascular epithelioid cell tumor (PEComa) in the genitourinary tract.

Perivascular epithelioid cell tumors (PEComas) are mesenchymal tumors composed of histologically, immunohistochemically, ultrastructurally, and genetically distinctive cells. PEComas have been described in different organs and are considered ubiquitous tumors. In this review we discuss recent informations related to PEComas in the genitourinary tract.

Molecular Pathology of Lymphangioleiomyomatosis and Other Perivascular Epithelioid Cell Tumors

CONTEXT Lymphangioleiomyomatosis (LAM) is a cystic lung disease that can be included in the wide group of proliferative lesions named PEComas (perivascular epithelioid cell tumors). These proliferative tumors are characterized by the coexpression of myogenic and melanogenesis-related markers. In all these lesions, genetic alterations related to the tuberous sclerosis complex (TSC) have been demonstrated. Striking improvements in the understanding of the genetic basis of this autosomal dominant genetic disease are coupled to the understanding of the mechanisms that link the loss of TSC1 (9q34) or TSC2 (16p13.3) genes with the regulation of the Rheb/m-TOR/p70S6K pathway. These data have opened a new era in the comprehension of the pathogenesis of LAM and have also suggested new therapeutic strategies for this potentially lethal disease. OBJECTIVE To present and discuss the pathologic and molecular features of LAM within the spectrum of PEComas, providing a rational approach to their diagnosis. DATA SOURCES The published literature and personal experience. CONCLUSIONS The inclusion of LAM within the PEComa category is supported by a variety of biologic data and can significantly help in providing a comprehensive view of this interesting and clinically relevant group of lesions. The demonstration of molecular alterations of the mTOR pathway in LAM and other PEComas represents a rational basis for innovative therapeutic approaches with inhibitors of mTOR signaling.

Is There Still a Role for Fine-Needle Aspiration Cytology in Breast Cancer Screening? : Experience of the Verona Mammographic Breast Cancer Screening Program With Real-time Integrated Radiopathologic Activity (1999-2004)

Pre-operative diagnostic procedures are adopted in the investigation ofsuspicious or equivocal screen-detected breast lesions to avoidunnecessary open biopsy. The high-quality performance of a nono-perative procedure provides the best benign-to-malignant ratio inopen biopsy. The quality assurance system is an integrated part ofbreast screening programs

Cancer size, histotype, and cellular grade may limit the success of fine‐needle aspiration cytology for screen‐detected breast carcinoma

Fine‐needle aspiration cytology (FNAC) was adopted as the first‐line method to assess breast lesions in the Verona Breast Cancer Screening Program. The radiological and pathological factors relating to the success of FNAC in breast cancer series were evaluated.

Benign breast lesions at risk of developing cancer - a challenging problem in breast cancer screening programs: five years' experience of the Breast Cancer Screening Program in Verona (1999-2004).

Cytology and core‐needle biopsies are not always sufficient to exclude malignancy in benign breast lesions (BBL) that are at risk of developing cancer, and open biopsy often is mandatory. In screening programs, open biopsies performed for lesions that are at risk of developing malignancy are considered benign. The authors of this report evaluated the impact of the screen‐detected BBL at risk of developing cancer that were counted in the quota of benign breast open biopsies in the Breast Cancer Screening Program of Verona.

Her-2/neu evaluation in Sister Mary Joseph's nodule from breast carcinoma: a case report and review of the literature

Sister Mary Joseph’s nodule (SMJN) involving the umbilicus can often be a clinical sign of metastatic cancer, but rarely cancer originating from the breast. We report a rare case of umbilical metastases from breast cancer and reviewed the literature. A 54‐year‐old woman was referred to a pre‐surgery clinic for an examination of an umbilical nodule. The patient had a history of ductal breast carcinoma. Cytological smear from fine needle aspiration showed epithelial neoplastic cells resembling those of breast carcinoma. Neoplastic cells from tissue were positive for cytokeratin 8–18, estrogen and progesterone receptor and negative for E‐cadherin and had a low proliferative index. Her‐2/neu immunodetection showed a 2+ equivocal positive rate, but Her‐2/neu gene amplification was found on the cytological smear by fluorescence in situ hybridization analysis. Similar results were obtained within a tissue section. Concordant findings have been obtained when comparing the recent American Society of Clinical Oncology/College of American Pathologists scoring system. Fine needle aspiration from the SMJN is a useful tool for the diagnosis of metastatic breast cancer. Furthermore, the predictive biomarkers for tumors of the breast, hormonal receptors and Her‐2/neu not only assist with the identification of the source of the metastatic disease but also provide clinical information for patient management.