Complete spontaneous regression of a primary renal cell carcinoma. Report of a pathological proven case and review of the literature.

Regression of primary renal cell carcinoma (RCC) is a rare phenomenon and for several reasons many of the reported cases have been questioned. We present a case that can be considered a true spontaneous and complete regression of a primary RCC. A 79-year-old female underwent nephrectomy because a renal tumor. At the time of surgery image studies showed a small para-aortic lymph node. The tumor measured 3cm and was analyzed completely. Histology showed a fibro-inflammatory lesion with necrosis, foamy macrophages and inflammatory cells. No neoplastic cells were observed and the lesion was interpreted as a localized type of xanthogranulomatous pyelonephritis. One year later a CT control scan, showed that the para-aortic lymph node had increased in size to 4cm. Fine needle aspiration revealed features of clear RCC. Metastatic dissemination was limited so surgical removal of the para-aortic lymph node was performed and the cytologic diagnosis confirmed.

Fine needle aspiration cytology of a myxoid adrenocortical adenoma. A case report.

The myxoid variant of adrenocortical (AC) tumors is characterized by peculiar histologic features that differ from conventional ones. It shows a prominent myxoid stromal component and is composed of small cells with mild atypia arranged in cords, pseudoglandular structures and microcysts. Reflecting the rarity of this variant, very few cytologic descriptions are available. We describe one case in a 41-year-old woman with a previous diagnosis of breast carcinoma and BRCA1 mutation. During follow-up controls, an adrenal tumor was discovered. Fine needle aspiration cytology and Tru-Cut biopsies were performed simultaneously. Smears showed numerous groups of cohesive cells of intermediate to small size. Within the largest groups, aggregates of myxoid metachromatic material were evident. This myxoid material could also be observed as isolated acellular fragments. While the cytoplasm of most tumoral cells was homogenously stained some showed small vacuoles. Histologically, the tumor grew, forming anastomosing cords, separated by myxoid material that determined microcystic spaces. Immunohistochemistry was characteristic of AC myxoid tumor. After surgery, pathologic analysis confirmed this diagnosis. The tumor showed no necrosis or invasion, had a low mitotic index (3/50 high power fields) and Ki-67 proliferative index of 15%. According to the different diagnostic systems the tumor was classified as an adenoma. In conclusion, the myxoid variant of AC tumors shows peculiar cytologic features. If unaware of the existence of this variant, it can easily be misinterpreted as a metastatic tumor.

Fine needle aspiration cytology of the normal kidney: A cyto-histological and immunocytochemical correlation study.

BACKGROUND: Differentiation between normal renal cellular structures and renal tumors can be a diagnostic challenge during fine needle aspiration. It is of particular relevance during percutaneous thermal ablation because of the small size of tumors and when performing rapid on-site evaluation. METHODS: A cyto-histological correlation study assisted by immunocytochemistry was performed. The study was based on 10 nephrectomy specimens. For the identification of proximal tubular cells we used CD10 and α-methylacyl coenzyme A racemase (AMACR). PAX8 and GATA3 were used for the recognition of distal and collecting duct cells. For a precise correlation representative cytologic groups were photographed before and after immunocytochemistry. RESULTS: All cases showed: (a) glomeruli; (b) presence of at least 2 different epithelial cell populations that distribute separately, one representing the proximal tubule and the other more distal segments; and (c) existence of isolated, laminar basement fragments and slender, intact tubular structures. Proximal tubular cells were large with granular cytoplasm, indistinct cell borders, moderate anisonucleosis, and variable presence of pigment. Their immunophenotype was CD10+, AMACR+, PAX8-, and GATA3-. In all cases, cellular aggregates different of nonproximal tubular cells were present. They were smaller than proximal tubular cells with less cytoplasm, better-defined cell borders and uniform nuclei. Their immunophenotype was CD10-, AMACR-, PAX8+, and GATA3+ CONCLUSION: Aspirates from the normal kidney show characteristic features that permit a specific recognition. Different segments of the tubular system can be specifically recognized avoiding confusion with renal tumors. In difficult cases immunocytochemistry is a very helpful aid.

Metástasis hepáticas de carcinoma neuroendocrino tras el tratamiento con los nuevos antivirales frente al virus de la hepatitis C en un paciente previamente tratado de un hepatocarcinoma / Liver metastasis from neuroendocrine carcinoma after the use of the new direct-action antivirals against hepatitis C virus in a patient with past history of hepatocellular carcinoma

El uso de los nuevos fármacos antivirales de acción directa frente al virus de la hepatitis C provee unas tasas muy elevadas de erradicación viral. No obstante, se están publicando de forma reciente artículos que defienden la precaución en su uso al documentarse algunos casos de tumores de novo tanto hepáticos como extrahepáticos, así como una mayor rapidez de aparición de recurrencias de hepatocarcinomas previamente tratados mediante cirugía o terapias locorregionales. El rápido descenso de las células natural killer con los tratamientos antivirales libres de interferón se ha propuesto como uno de los posibles mecanismos que podrían explicar este proceso, si bien, dada la controversia a este respecto y la ausencia de estudios a largo plazo en la práctica clínica, se requiere precaución antes de establecer conclusiones definitivas. Presentamos el caso clínico de un paciente con hepatopatía crónica por el virus de la hepatitis C y hepatocarcinoma en remisión completa tras tratamiento ablativo con radiofrecuencia que fue tratado con los nuevos antivirales de acción directa, consiguiendo respuesta virológica sostenida. Seis meses después el paciente fue diagnosticado de metástasis hepáticas de un carcinoma neuroendocrino de célula pequeña de tumor primario no conocido (AU)

The use of the new direct-action antivirals against hepatitis C virus provides very high viral eradication rates. However, various recently published articles recommend caution with their use after the appearance of some cases of de novo tumors (originated in hepatic and extra-hepatic locations) and a possible shorter time period of recurrence of hepatocellular carcinomas previously treated with surgery or loco-regional therapies. The sudden drop of the number of natural killer cells secondary to the use of these new medicines has been suggested as one of the possible mechanisms responsible for this process. However, due to the controversy concerning this subject and the absence of long-term follow-up studies in clinical practice, caution is needed before definitive conclusions are settled. We present the case report of a patient diagnosed of chronic liver disease secondary to hepatitis C virus infection and a past history of hepatocellular carcinoma in complete remission after radiofrequency ablation. He was treated with the new direct-action antivirals reaching sustained viral response. Six months later, the patient was diagnosed with liver metastasis from a small-cell neuroendocrine tumor of unknown primary site (AU)

Liver metastasis from neuroendocrine carcinoma after the use of the new direct-action antivirals against hepatitis C virus in a patient with past history of hepatocellular carcinoma.

The use of the new direct-action antivirals against hepatitis C virus provides very high viral eradication rates. However, various recently published articles recommend caution with their use after the appearance of some cases of de novo tumors (originated in hepatic and extra-hepatic locations) and a possible shorter time period of recurrence of hepatocellular carcinomas previously treated with surgery or loco-regional therapies. The sudden drop of the number of natural killer cells secondary to the use of these new medicines has been suggested as one of the possible mechanisms responsible for this process. However, due to the controversy concerning this subject and the absence of long-term follow-up studies in clinical practice, caution is needed before definitive conclusions are settled. We present the case report of a patient diagnosed of chronic liver disease secondary to hepatitis C virus infection and a past history of hepatocellular carcinoma in complete remission after radiofrequency ablation. He was treated with the new direct-action antivirals reaching sustained viral response. Six months later, the patient was diagnosed with liver metastasis from a small-cell neuroendocrine tumor of unknown primary site.

Cytologic features of pleomorphic xanthoastrocytoma, WHO grade II. A comparative study with glioblastoma.

Pleomorphic xanthoastrocytoma (PXA) is a WHO grade II astrocytic tumor of children and young adults. It is characterized by pleomorphic, atypical astrocytes. Atypia is so remarkable, that PXA can be easily misdiagnosed as malignant glioma. If confused with a high-grade glioma the neurosurgeon may not proceed with a complete resection. Therefore, a specific recognition during intraoperative consultation is particularly important. We describe four cases of PXA evaluated during intraoperative procedures. Findings were compared with those of 22 glioblastomas. PXA smears were moderately cellular and showed a variable population of pleomorphic cells and fibrillary fragments with vessels. Tumoral cells were of intermediate size with a less frequent population of large, atypical cells. Some showed bi/trinucleation with bizarre nuclei. In two cases, tumoral cells with microvacuolization resembling xanthic astrocytes were present. No necrosis, mitotic activity, phagocytic macrophages or apoptotic fragments were seen. Smears from glioblastoma were more cellular than those of PXA with numerous neoplastic cells, branching vessels and myxoid substance. Cellular atypia was evident and mitoses were seen in all cases. Most cases showed an abundant population of accompanying macrophages and cellular debris. Differences between PXA and glioblastoma were related to cell turnover rather than cytomorphologic features. Glioblastoma shows features of high cellular replication showing a dirty background with necrosis and phagocytic macrophages as well as mitotic figures and apoptosis. On the other hand, smears from PXA have a clean background with no necrosis, cellular fragments or relevant mitotic activity. Diagn. Cytopathol. 2017;45:339-344. © 2016 Wiley Periodicals, Inc.