Morphological predictors for microsatellite instability in urothelial carcinoma.

INTRODUCTION: Microsatellite instability occurs due to a series of mutations in the DNA pairing error repair (Mismatch repair; MMR) genes, which can affect germ cells as occurs in Lynch syndrome, whose patients are at high risk of developing multiple cancers. The loss of MMR protein is commonly determined by immunohistochemical studies. Although the relation between microsatellite instability and urothelial carcinomas has been widely studied, its evaluation is not currently performed in the analysis of urothelial carcinomas. METHODS: In this study, the microsatellite status of 139 urothelial carcinomas was analyzed and their clinicopathological characteristics were evaluated. We identified that 10.3% (13 patients) of urothelial carcinomas had loss of MMR protein expression (9 MLH1; 5 MSH2; 2 PMS2; 2 PSH6; n = 139). RESULTS: Results suggest that these tumors occur more frequently in males, are more frequently located in the bladder or ureters, and present a high tumor grade with a papillary histological pattern that does not infiltrate the lamina propria or, in the case of infiltrating tumors, that grows into perivesical tissues. CONCLUSIONS: We identified patients with the aforementioned tumor characteristics as patients with a high probability of presenting loss of MMR protein expression, and consider that only these patients should undergo further immunohistochemical and molecular techniques for proper diagnosis. Therefore, we propose that the clinicopathological characteristics found in the present study could become possible markers to determine which cases should undergo additional tests.

Rate of non-invasive follicular thyroid neoplasms with papillary-like nuclear features depends on pathologist's criteria: a multicentre retrospective Southern European study with prolonged follow-up.

PURPOSE: To determine the rate of non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) in a multi-institutional series from the Iberian Peninsula and describing this NIFTP cohort. METHODS: Retrospective study of papillary thyroid carcinoma (PTC) or well-differentiated tumours of uncertain malignant potential (WDT-UMP) diagnosed between 2005 and 2015 and measuring ≥5 mm in adult patients from 17 hospitals. Pathological reports were reviewed to determine the cases that fulfil the original criteria of NIFTP and histology was reassessed. Rates were correlated with the number of PTC and its follicular variant (FVPTC) of each institution. Demographic data, histology, management, and follow-up of the reclassified NIFTP cohort were recorded. RESULTS: A total of 182 cases with NIFTP criteria were identified: 174/3372 PTC (rate: 5.2%; range: 0-12.1%) and 8/19 WDT-UMP (42.1%). NIFTP rate showed linear correlation with total PTC (p: 0.03) and FVPTC (p: 0.007) identified at each centre. Ultrasound findings were non-suspicious in 60.1%. Fine-needle cytology or core biopsy diagnoses were undetermined in 49.7%. Most patients were treated with total thyroidectomy. No case had nodal disease. Among patients with total thyroidectomy, 89.7% had an excellent response evaluated 1 year after surgery. There were no structural persistence or relapses. Five patients showed residual thyroglobulin after 90 months of mean follow-up. CONCLUSIONS: NIFTP rate is low but highly variable in neighbouring institutions of the Iberian Peninsula. This study suggests pathologist's interpretation of nuclear alterations as the main cause of these differences. Patients disclosed an excellent outcome, even without using the strictest criteria.

Cistoadenocarcinoma mucinoso retroperitoneal: presentación de un caso / Retroperitoneal mucinous cystadenocarcinoma: a case report

Antecedentes: Los cistoadenocarcinomas mucinososretroperitoneales primarios son neoplasias muy poco frecuentes.Hay 34 casos descritos en la literatura inglesa y continúasiendo controvertida su patogénesis. Métodos: Presentamosel caso de una mujer de 47 años con una lesión quísticaasintomática de 8 cm de longitud diagnosticada dequiste cortical renal, en otro centro. En revisiones posterioresla lesión alcanza 23 cm de diámetro. Es remitida al Hospitalde Móstoles donde se realiza un TAC que es informadocomo quiste mesotelial o linfangioma retroperitoneal. Losniveles de alfa-fetoproteína estaban dentro de la normalidad.Se realiza su resección quirúrgica. El Servicio de AnatomíaPatológica recibe una tumoración quística unilocular, quepesa 4.300 gramos y mide 24 × 18 × 15 cm, cuyos cortes histológicosmuestran un epitelio mucosecretor con áreas sólidaspapilares y focos infiltrativos pobremente diferenciados.Seis meses después de la cirugía no hay evidencia de recidivaneoplásica. Resultados y conclusiones: Los cistoadenocarcinomasmucinosos retroperitoneales primarios presentanun curso clínico agresivo, cuyo tratamiento de elección esquirúrgico y en ocasiones quimioterápico. Respecto a supatogenia existen diversas teorías: unas postulan su origen entejido ovárico heterotópico, otras en un teratoma retroperitonealo duplicación intestinal. La hipótesis mas aceptadaactualmente es el desarrollo a partir de metaplasia mucinosadel mesotelio celómico. Es importante tener presente al cistoadenocarcinomamucinoso retroperitoneal en el diagnósticodiferencial de otros tumores quísticos retroperitoneales(AU)

Introduction: Retroperitoneal mucinous cystadenocarcinomais extremely rare, with only 34 cases published todate. The pathogenesis of this tumour remains controversial.Materials and methods: This case report presents a 47 yearold woman who was being investigated for a renal cyst. An8cm retroperitoneal cystic mass was seen initially but, onsubsequent examination, it had increased to 23 cm in diameter.A CT scan rendered a diagnosis of mesothelial cystor retroperitoneal lymphangioma. á-fetoprotein levels werenormal. The tumour was surgically excised. Macroscopicallyit was a 24 × 18 × 15 cm, unilocular, cystic tumourwith solid areas. Microscopically, it was seen to be lined bymucinous epithelial cells with poorly differentiated areas. 6months post-operatively, she is alive and well and withoutevidence of recurrence. Results and conclusions: Retroperitonealmucinous cystadenocarcinoma has an aggressiveclinical course, and surgical excision is the treatment ofchoice, followed by chemotherapy on some occasions. Thereare various hypotheses for the pathogenesis of thistumour, including an origin from heterotopic ovarian tissue,retroperitoneal teratoma or intestinal duplication. However,the most widely accepted theory is that of coelomic metaplasia.Although rare, these tumours should be included inthe differential diagnosis of retroperitoneal cystic tumours(AU)

Multicentric myxoid liposarcoma: report of two cases.

BACKGROUND: Multicentric myxoid liposarcoma is a rather infrequent tumour that tends to behave aggressively. CASE PRESENTATION: We herein report two further cases of this tumour that have been managed in our Hospital. Both were young men with multiple sites of involvement at the moment of diagnosis and both have shown a bad prognosis with frequent recurrences after treatment and rapid death in one case. CONCLUSION: We comment on the diagnosis of this entity and on the therapeutic options available for these patients.

Sarcoma sinovial intramandibular. A propósito de un caso / Synovial sarcoma of the mandible. A case report

Introducción: El sarcoma sinovial es un tumor de partes blandas poco frecuente en cabeza y cuello y excepcional en la mandíbula. Presentación del caso: Presentamos un caso de un paciente de 74 años previamente diagnosticado y tratado de osteosarcoma mandibular, que muestra una tumoración en el remanente mandibular con extensión infratemporal. El diagnóstico con microscopía óptica, técnicas inmunohistoquímicas y ultraestructura fue de sarcoma sinovial monofásico. Se realizó estudio genético para la traslocación t (x;18) que resultó positiva, confirmándose el diagnóstico de recidiva local por sarcoma sinovial. La biopsia previa estaba erróneamente diagnosticada. Conclusiones: El sarcoma sinovial monofásico requiere diagnóstico diferencial con otras entidades. Es una tumoración que recidiva en más de la mitad de los casos y presenta un riesgo elevado de metástasis. Su diagnóstico exacto necesita un buen procesamiento tisular, técnicas inmunohistoquímicas, ultraestructurales y estudio genético

Introduction: Synovial sarcoma is an unusual soft tissue tumour of the head and neck. It is extremely rare on the mandible. Case presentation: We present here a case of a 74 year-old man previously diagnosed and treated of jaw osteosarcoma. Five years later the patient showed a neoplasm recurrence on the remaining mandibular condyloid, extending to the temporal bone. The diagnosis with light microscopy, immunohistochemical staining, and ultrastructure was monophasic synovial sarcoma. The characteristic chromosomal translocation t(x;18) was founded on the cytogenetic study, confirming the diagnosis of local recurrence of synovial sarcoma. The previous biopsy was misdiagnosed. Conclusions: The monophasic synovial sarcoma needs a differential diagnosis with other neoplasms. More than 50% of the cases shows recurrence and have a high rate of distant metastases. Adequate tissue sampling, immunohistochemical, ultraestructural and characteristic chromosomal translocation findings are necessary for diagnosis

Sarcoma sinovial intramandibular. A propósito de un caso / Synovial sarcoma of the mandible. A case report

Introducción: El sarcoma sinovial es un tumor de partes blandas poco frecuente en cabeza y cuello y excepcional en la mandíbula. Presentación del caso: Presentamos un caso de un paciente de 74 años previamente diagnosticado y tratado de osteosarcoma mandibular, que muestra una tumoración en el remanente mandibular con extensión infratemporal. El diagnóstico con microscopía óptica, técnicas inmunohistoquímicas y ultraestructura fue de sarcoma sinovial monofásico. Se realizó estudio genético para la traslocación t (x;18) que resultó positiva, confirmándose el diagnóstico de recidiva local por sarcoma sinovial. La biopsia previa estaba erróneamente diagnosticada. Conclusiones: El sarcoma sinovial monofásico requiere diagnóstico diferencial con otras entidades. Es una tumoración que recidiva en más de la mitad de los casos y presenta un riesgo elevado de metástasis. Su diagnóstico exacto necesita un buen procesamiento tisular, técnicas inmunohistoquímicas, ultraestructurales y estudio genético

Introduction: Synovial sarcoma is an unusual soft tissue tumour of the head and neck. It is extremely rare on the mandible. Case presentation: We present here a case of a 74 year-old man previously diagnosed and treated of jaw osteosarcoma. Five years later the patient showed a neoplasm recurrence on the remaining mandibular condyloid, extending to the temporal bone. The diagnosis with light microscopy, immunohistochemical staining, and ultrastructure was monophasic synovial sarcoma. The characteristic chromosomal translocation t(x;18) was founded on the cytogenetic study, confirming the diagnosis of local recurrence of synovial sarcoma. The previous biopsy was misdiagnosed. Conclusions: The monophasic synovial sarcoma needs a differential diagnosis with other neoplasms. More than 50% of the cases shows recurrence and have a high rate of distant metastases. Adequate tissue sampling, immunohistochemical, ultraestructural and characteristic chromosomal translocation findings are necessary for diagnosis