RESUMEN
BACKGROUND: Tenosynovial giant cell tumor (TSGCT), also known as giant cell tumor of tendon sheath or pigmented villonodular synovitis, is the most common benign tumor of the tendon and synovium. The intra-articular diffuse type can present as a large infiltrative mass involving adjacent soft tissue and sometimes causes secondary destruction of bone, which leads to radiographic and clinical concern for malignancy. The tumor may also be purely extra-articular. CASE: Here, we report the fine needle aspiration cytology findings of 2 cases of diffuse-type TSGCT with large mononuclear cells with eccentric nuclei, finely granular cytoplasm, and a peripheral well-defined cytoplasmic rim of hemosiderin ("ladybird cells"). CONCLUSION: Although the presence of ladybird cells has been described in tissue sections of TSGCT, their identification in cytological specimens has not been reported to our knowledge. When observed, their presence may aid in differentiating TSGCT from other lesions with multinucleated osteoclast-type giant cells occurring at or near joints.
Asunto(s)
Biopsia con Aguja Fina , Tumor de Células Gigantes de las Vainas Tendinosas/diagnóstico , Células Gigantes/patología , Anciano , Colorantes Azulados , Biomarcadores de Tumor/análisis , Núcleo Celular/patología , Diagnóstico Diferencial , Femenino , Tumor de Células Gigantes de las Vainas Tendinosas/química , Tumor de Células Gigantes de las Vainas Tendinosas/patología , Células Gigantes/química , Hemosiderina/análisis , Humanos , Imagen por Resonancia Magnética , Masculino , Azul de Metileno , Prueba de Papanicolaou , Valor Predictivo de las Pruebas , Tomografía Computarizada por Rayos X , XantenosRESUMEN
Diffuse-type tenosynovial giant cell tumor (D-T TSGCT) is regarded as a benign but locally aggressive neoplasm with significant recurrent potential. We report a case of malignant D-T TSGCT with pleural metastases arising in the left knee in a 57-year-old man. The tumor demonstrated atypical features, including a solid infiltrative pattern with spindling of the tumor cells, nuclear pleomorphism with prominent nucleoli, and markedly increased mitotic activity (>20 mitoses/10 high-power fields). The immunoprofile demonstrated clusterin+, D2-40+, CD68+, p63+, MDM2+, and p16+ tumor. The next-generation sequencing-based assay demonstrated loss of the CDKN2A/B gene. Pleural metastases with identical histologic and immunohistochemical features were identified 2 years later after primary tumor resection. To the best of our knowledge, this is the first reported case of D-T TSGCT with CDKN2A/B genomic alteration, MDM2 expression, and p16 loss. Clinicians and pathologists should be aware of the morphologic variability and the metastatic propensity of this entity.