Thyroid collision tumor containing oncocytic carcinoma, classical and hobnail variants of papillary carcinoma and areas of poorly differentiated carcinoma

SUMMARY Collision tumors are rare and may comprise components with different behavior, treatments, and prognosis. We report an unprecedented case of aggressive thyroid collision tumor containing widely invasive oncocytic carcinoma (OC), classical and hobnail (HPTC) variants of papillary carcinoma, and poorly differentiated carcinoma (PDTC). The patient underwent total thyroidectomy, radioactive iodine therapy, and within months progressed with local recurrence, and pulmonary metastases requiring neck dissection, external radiotherapy and systemic treatment with sorafenib. The rapid progression, dedifferentiated metastatic lesions, and failure to treatments resulted in the patient´s death. The great variety of histological types and the evolution of this case were a challenge for the management of metastatic disease. Widely invasive OC, HPTC and PDTC are considered to have a worse prognosis. HPTC has never been reported as a component of a collision tumor. HPTC and PDTC should call attention to a possible higher-grade transformation.

Doença sistêmica relacionada à IgG4 com linfopenia: relato de caso e breve revisão de literatura / IgG4-related systemic disease associated with lymphopenia: case report and brief literature review

A doença sistêmica relacionada à IgG4 é uma doença emergente, recentemente descrita, caracterizada clinicamente por aumento parcial ou total de um órgão, e, por isso, com amplo espectro de manifestações clínicas. Esta é uma doença sistêmica fibroinflamatória, patologicamente provocada pela infiltração de plasmoblastos IgG4 positivos que levam à inflamação eosinofílica do tecido e, consequentemente, fibrose estoriforme. Quando o diagnóstico é precoce, a melhora clínica e resposta sustentada com corticosteroides sistêmicos é impressionante. O diagnóstico é baseado em critérios patológicos, mas, recentemente, alguns trabalhos têm descrito que plasmoblastos no soro podem servir como um fator independente para auxiliar no diagnóstico da doença. Este artigo descreve uma apresentação atípica da doença relacionada à IgG4, em um paciente linfopênico com medição inconclusiva de plasmoblastos no soro.

IgG4-related systemic disease is a recently described, emerging condition, clinically characterized by partial or total enlargement of an organ, with a broad spectrum of clinical manifestations. It is a systemic fibroinflammatory condition caused by the infiltration of IgG4-positive plasmablasts that lead to eosinophilic inflammation of tissues and consequently storiform fibrosis. When diagnosis is early, clinical improvement and maintained response achieved with systemic corticosteroids is impressive. Diagnosis is based on pathological criteria, but recent papers have described that serum plasmablasts may serve as an independent factor to aid in diagnosis. This paper describes an atypical presentation of IgG4-related disease in a lymphopenic patient with inconclusive serum plasmablast measurement.