RESUMO
Capicua transcriptional repressor (CIC)-rearranged sarcomas are part of the group of Ewing-like sarcomas or atypical Ewing sarcomas which, thanks to the progress in molecular diagnosis, are being defined by particular genetic abnormalities separating this group into distinct entities with their own particular histological and immunohistochemical features, as well as different survival outcomes. We report the case of a healthy 28-year-old female presenting with a tender lesion on her forearm which after ultrasound examination was clinically favored to represent an infected sebaceous cyst. Hematoxylin-eosin staining showed a lobulated neoplasm within the subcutis composed of poorly differentiated epithelioid to round cells with a small amount of amphophilic cytoplasm. Frequent mitotic figures and tumor necrosis were present. Immunohistochemical studies showed patchy focal CD99 membranous positivity, negative WT1 and TLE1 staining and diffuse nuclear positivity for ETV4 (performed at outside laboratory). FISH analysis showed significant CIC rearrangement enabling a final diagnosis of an undifferentiated small round cell sarcoma harboring the t(4;19)(q35;q13.1) and CIC-DUX4 fusion. This case shows the importance of awareness of this entity as, unlike Ewing sarcoma, these lesions present in the soft tissues rather than bone and may, as in this case, arise in the superficial soft tissues and be submitted to a dermatopathology practice.
Assuntos
Cisto Epidérmico , Antebraço , Rearranjo Gênico , Proteínas de Homeodomínio , Proteínas de Fusão Oncogênica , Proteínas Repressoras , Sarcoma de Células Pequenas , Neoplasias Cutâneas , Adulto , Cromossomos Humanos Par 19/genética , Cromossomos Humanos Par 19/metabolismo , Cromossomos Humanos Par 4/genética , Cromossomos Humanos Par 4/metabolismo , Proteínas Correpressoras/genética , Proteínas Correpressoras/metabolismo , Cisto Epidérmico/genética , Cisto Epidérmico/metabolismo , Cisto Epidérmico/patologia , Feminino , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Hibridização in Situ Fluorescente , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Proteínas Proto-Oncogênicas c-ets/genética , Proteínas Proto-Oncogênicas c-ets/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Sarcoma de Células Pequenas/genética , Sarcoma de Células Pequenas/metabolismo , Sarcoma de Células Pequenas/patologia , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Translocação Genética , Proteínas WT1/genética , Proteínas WT1/metabolismoRESUMO
We present the diagnosis of bilateral granulomatous inflammation of the hip joints associated with Hylan G-F 20 viscosupplementation injections. Clinicians recommending therapeutic Hylan injections for the management of hip arthritis should maintain clinical awareness regarding this potential complication.
RESUMO
We present an incidentally discovered, unusual case of pulmonary bronchial mucosa-associated lymphoid tissue lymphoma associated with massive crystal storing histiocytosis in a 69-year-old woman. The neoplastic process was masked by large numbers of epithelioid and spindled histiocytes containing crystalline material. Histochemical stains showed intracytoplasmic crystals and immunoperoxidase staining confirmed the histiocytic nature of the swollen cells. Electron microscopy demonstrated the characteristic appearance of immunoglobulin crystals. Lymphoepithelial lesions were identified on immunohistochemical staining, compounding suspicions of an underlying lymphoid neoplasm. Molecular studies later revealed a monoclonal B-cell population. The patient had no systemic evidence of a paraproteinemia. Crystal storing histiocytosis is a rare phenomenon in which macrophages accumulate light chain or immunoglobulin crystalline inclusions. The disease may be systemic, or localized as in this case. It is usually associated with the excess production of a monoclonal immunoglobulin, although there have been many case reports without this feature. An overview of crystal storing histiocytosis is given.