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Botucatu, Brazil

Falconieri G.,General Hospital S. Maria della Misericordia | Bacchi C.E.,Consultoria em Patologia | Luzar B.,University of Ljubljana
American Journal of Dermatopathology | Year: 2012

Clear cell sarcoma is a unique soft tissue tumor with distinct microscopic features that include a nested or fascicular pattern of spindle cells accompanied by larger wreath-like giant cells scattered throughout. It harbors a unique EWSR1-ATF1 gene fusion secondary to a t(12;22)(q13;q12) translocation. Recently, it was reported that clear cell sarcoma can occur in the skin and mimic a broad spectrum of entities, including spindle cell melanoma. Here, we describe 3 new cases of clear cell sarcoma of the skin, all of which were confirmed molecularly. The patients, a 12-year-old boy, a 29-year-old woman, and a 60-year-old man, had cutaneous lesions on the thigh, dorsum of foot, and sole, respectively. All 3 lesions were originally considered suspicious of spindle cell melanoma. Microscopically, the lesions featured nodular proliferation centered in the dermis that consisted of discrete fascicles of spindle cell enmeshed by thin fibrous strands. Wreath-like cells were present in all cases. Tumor cells were positive for S100 protein (3 of 3 cases), melan A (2 of 3 cases), HMB 45 (1 of 3 cases) although a junctional melanocytic proliferation was seen in 1 case. Sentinel lymph node biopsy was negative in 2 patients. Follow-up was uneventful in 2 patients, whereas the other patient developed a lymph node metastasis 5 months after primary tumor excision. This study confirms that malignant dermal tumors that mimic but do not exactly replicate spindle cell melanoma should raise suspicion for cutaneous clear cell sarcoma and prompt the investigation for the confirmatory gene fusion t(12;22). © 2012 by Lippincott Williams & Wilkins. Source

Weiss L.M.,City of Hope National Medical Center | Bacchi C.E.,Consultoria em Patologia
Applied Immunohistochemistry and Molecular Morphology | Year: 2010

The identification of monotypic light chains is an important adjunct to the diagnosis of B-cell lymphoma, yet to reliably perform it on formalin-fixed paraffin sections is often difficult. We have evaluated a new set of monoclonal antibodies to κ and λ light chains that are reactive in paraffin sections. In reactive lymphoid tissues, polytypic staining was noted in greater than 95% of cases, with strong staining of plasma cells, moderate staining of the follicular dendritic cell network, and weak staining of mantle zone cells. Strong staining of the appropriate light chain was seen in each of the 7 cases of multiple myeloma. In a series of 58 cases of B-cell lymphoma, correlation between the results of immunohistochemistry and flow cytometry was obtained in 36 cases (62%), including 32 cases (21 κ and 11 λ) in which a single light chain was expressed. Monotypic staining was also seen in 6 additional cases (10%) in which flow cytometry was negative. Thirty of 46 cases (65%) of follicular lymphoma showed monotypic light chain expression, in contrast to 64 of 67 cases (95%) of reactive lymphoid hyperplasia, which showed polytypic light chain expression. These antibodies may provide an effective adjunct to the diagnosis of B-cell lymphoma in routine diagnostic work. Copyright © 2010 by Lippincott Williams & Wilkins. Source

Salviato T.,General Hospital S. Maria Degli Angeli | Bacchi C.E.,Consultoria em Patologia | Luzar B.,University of Ljubljana | Falconieri G.,University of Udine
American Journal of Dermatopathology | Year: 2013

We report 2 cases of cutaneous epithelioid angiosarcoma featuring predominantly signet ring cells. The patients-a woman, 68 years of age, and a man, 85 years of age, respectively-were referred for slowly growing indurated plaques on their parietal and retroauricular skin. Microscopic examination showed diffuse dermal proliferations comprising polygonal cells and relatively abundant cytoplasm. Because the tumor cells often were distended by variably sized vacuoles pushing the nuclei to the periphery, the nuclear profile tended toward a crescent-like morphology. Abortive luminal formations were recognized. The tumor cells were positive for CD31, CD34, and D2-40/podoplanin, with no expression of epithelial or melanocytic markers. In 1 case, upon ultrastructural examination of paraffin-embedded tissue-cut from wax tissue and reprocessed-the optically empty spaces were surrounded by a membrane with ultrastructural features identical to those of the outer cell membrane, suggesting that these spaces corresponded to the formation of primitive intracytoplasmic lumina within the tumor cells. A few Weibel-Palade bodies also were noted. Our report offers further evidence that epithelioid angiosarcoma of the skin has a broad microscopic spectrum and that tumors displaying a preponderant population of signet ring cells pose further diagnostic challenges. A brief overview of cutaneous malignant tumors in the differential diagnosis of signet ring cell angiosarcoma is provided. © 2013 Lippincott Williams &Wilkins. Source

Chisholm K.M.,Stanford University | Bangs C.D.,Stanford University | Bacchi C.E.,Consultoria em Patologia | Molina-Kirsch H.,Laboratorio Of Patologia | And 2 more authors.
American Journal of Surgical Pathology | Year: 2015

MYC translocations are a defining feature of Burkitt lymphoma and a group of diffuse large B-cell lymphoma (DLBCL) with inferior outcome. However, the clinical relevance of MYC gene rearrangement and its relationship with MYC protein expression has not been well characterized in lymphomas. Tissue microarrays containing 1214 lymphomas were successfully evaluated by immunohistochemistry using anti-MYC clone Y69 and a dual-color break-apart fluorescence in situ hybridization probe to detect MYC gene rearrangements. Aggressive B-cell lymphomas including Burkitt lymphoma and DLBCL showed the highest level of MYC protein staining defined as staining in >50% of lymphoma cells. A significant proportion of plasmablastic, B-lymphoblastic and T-lymphoblastic, and extranodal NK/T-cell lymphomas also showed staining in >50% of cells, whereas only occasional plasma cell myeloma, mantle cell lymphoma, and classical Hodgkin lymphoma showed a high level of staining. Small B-cell lymphomas, when positive, showed MYC protein in <50% of cells. In aggressive B-cell lymphomas, MYC rearrangement and MYC immunohistochemistry showed a high concordance rate; however, some DLBCL and all T-cell and NK-cell lymphomas with MYC protein expression lacked MYC gene rearrangements. Our results provide a baseline for MYC protein expression in lymphomas and indicate that its expression is not specific to lymphoma subtypes, cell lineage, or expected clinical behavior and is highly variable. In addition, MYC protein expression is not necessarily correlated with MYC gene rearrangements and suggests the need for caution in the interpretation of MYC immunohistochemistry in the differential diagnosis of lymphomas. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved. Source

Gualco G.,Consultoria em Patologia | Domeny-Duarte P.,Consultoria em Patologia | Chioato L.,Consultoria em Patologia | Barber G.,University of Miami | And 2 more authors.
American Journal of Surgical Pathology | Year: 2011

Extranodal natural killer/T-cell lymphoma, nasal type (NK/TCL) is more prevalent in Asia and in some areas of South and Central America, but it is rarely seen in the United States and Europe. In this study, a series of 122 cases of NK/TCL from Brazil was analyzed with respect to clinicopathologic features. Clinical characteristics and geographic distribution were evaluated in 97 cases of nasal/nasopharyngeal region and 23 cases in extranasal sites including 6 nodal cases. Clinical staging and follow-up information was available in a subset of 21 patients. All cases harbored Epstein-Barr virus (EBV), 95% and 85% expressed cytoplasmic CD3 and CD56, respectively, and all cases were positive for at least 1 marker for cytotoxic granules. The global distribution of EBV subtypes showed predominance of strain subtype A, 89%, and subtype B, 11%. No dual infections were detected. TCR-γ TCR-gene rearrangement was observed in 7 cases; all of them extranodal. Three of TCR-γ+ cases showed EBV subtype A. Two TCR-γ+/ CD56+ cases showed EBV subtype B. Geographic distribution of NK/TCL showed higher frequency in the southeast and northeast regions of Brazil. Striking differences among geographic regions were seen with the vast majority of EBV subtype B (86%) occurring in the south and southeast regions. Copyright © 2011 by Lippincott Williams & Wilkins. Source

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