Carcinoma de Células Escamosas de Tiroides: A Propósito de un Caso / Primary squamous cell thyroid carcinoma

El carcinoma de células escamosas de tiroides (CCET) es un tumor infrecuente y agresivo. Su etiología es incierta. Ante la presencia de carcinoma escamoso en la glándula tiroides debe excluirse la posibilidad de infiltración de un tumor originado en una estructura adyacente o de metástasis de otros carcinomas. El tratamiento de elección es la cirugía radical. La mayoría de los pacientes fallecen antes del año debido a progresión local de la enfermedad. Presentamos el caso de un paciente con una masa tiroidea, con diagnóstico histológico de carcinoma escamoso (con inmunohistoquímca negativa para tiroglobulina, TTF1 y calcitonina y positiva para p63 y citok5). Los estudios clínicos, endoscópicos y radiológicos excluyeron otros sitios de origen de carcinoma escamoso. Fue tratado con quimio y radioterapia, falleciendo por progresión local luego de 9 meses.

Primary squamous cell thyroid carcinoma (PSCTC) is a rare and aggressive tumor of uncertain origin. When squamous carcinoma is diagnosed, it is mandatory to exclude the possibility of primary tumor arising from an adjacent structure or representing metastases from a primary growth elsewhere. Aggressive surgical resection is the treatment of choice. However, the prognosis is poor, with a median survival of less than a year. Death is usually secondary to progression of local disease. We report a case of a patient presenting with a thyroid mass; biopsy was consistent with squamous cell carcinoma. On immunohistochemistry tumor cells were negative for TTF1, thyroglobulin and calcitonin. Cancer cells were positive for p63 and citok5. Extensive workup excluded the possibility of extrathyroid origin. The patient was treated with chemoradiotherapy; he died 9 months later due to local progression.

Linfoma de células en anillo de sello que simula carcinoma mucosecretante / Signet ring cell lymphoma mimicking mucin-producing carcinoma

Signet ring cell lymphoma is a rare neoplasm characterized by large, vacuolated and clear cells mimicking mucin-producing adenocarcinoma. It is localized in nodal and extranodal sites. A case of a 59 years old male, with a diffuse lymphoma signet ring cell type localized on oropharyngeal mucosa is reported. The histopathology study showed signet ring cells and the immunophenotype was: vimentine(+), CD45(+), CD20(+), Ig M(+), Kappa chain(+) and high index proliferative activity of neoplastic cells (Ki 67:70%). After a review of the literature and previous reports, we could not find a similar case in this anatomic site. The patient had a unfavourable clinical course and died two months after the diagnosis without receiving any treatment.

El linfoma de células en anillo de sello es una neoplasia poco frecuente, caracterizada por la presensenciade grandes células de citoplasma vacuolado, claro, similar a los encontrados en adenocarcinomasmucosecretantes. Se ha descripto en ganglios linfáticos y tejidos extralinfáticos. Se presenta el casode un paciente varón de 59 años con linfoma de células en anillo de sello localizado en pared lateral de orofaringe.Esta localización creemos que no ha sido descripta anteriormente. La histología mostró células en anillo de sello y el inmunofenotipo tumoral fue: vimentina, CD45, CD20, Ig M y cadenas kappa positivos, siendo la fracción de crecimiento tumoral alta (Ki 67:70%). El paciente evolucionó desfavorablemente y falleció a los dosmeses del diagnóstico sin recibir tratamiento.

Procesos linfoides B cutáneos con patrón nodular / Cutaneous B cell processes with nodular pattern

Cutaneous lymphomas are low grade malignant neoplasms with favourable prognosis. Those related to the germinal centre with nodular pattern may be: follicular lymphomas (LFC) or extranodal marginal zone B-cell lymphomas (LMC). They are difficult to tell apart, and from reactive processes like cutaneous follicular hyperplasia and cutis immunocytomas. The objective of this study was to check the incidence and the value of both histology and immunohistochemistry in differential diagnosis. Fifty six patients with cutaneous lymphomas were selected within the period 1995-2004. The biopsies were studied with hematoxilin eosin and immunohistochemistry. Thirty two out of the fifty six cutaneous lymphoid infiltrates were of T origin (57.1%) and twenty four of B origin (42.8%), ten out of this last figure (17.7%) were lymphoid processes with nodular pattern Four LFC, three LMC and three HLC were diagnosed. Convergent follicles with scarce mantle and germinal centres with monomorph celullarity were observed in the LFC. Among the LMC, follicles with prominent mantle and nests of monocitoid cells in the mantle, interfollicular zone and in the germinal centers observed. In the HLC macrophages with detritus were found in the germinal centers. LFC showed: CD20 (+), CD 10 (+), bcl-2 (+) or (-), and bcl-6 (+) in the follicle and in the interfollicular area. LMC showed: CD 20 (+), bcl-2 (-), CD 10 (+/-), and bcl-6 (+) in the follicle, and bcl-2 (+), CD10 (-/+) and bcl-6 (-) in the interfollicular area. The HLC results were: bcl-2 (-), bcl-6 (+) and CD 10 (-) in the follicle and bcl-2 (+), bcl-6 (-) and CD 10 (-) in the interfollicular zone. We conclude that lymphoid B cell processes with nodular pattern are unusual. Histology and immunohistochemistry proved to be useful in the differential diagnosis of these lymphomas, and for differentiating these from lymphoid hyperplasias or non tumoral hyperplasias.