Carcinoma hiperfuncionante paratiroideo con extensión mediastínica / Hyperfunctional parathyroid carcinoma with mediastinal extension

El carcinoma de paratiroides (CP) es una neoplasia maligna extremadamente rara, que constituye el 0,005% de todos los tumores y entre el 0,5 y el 5% de todas las neoplasias de las paratiroides. El diagnóstico clínico de CP es difícil y en la mayoría de los casos se realiza tras el examen histopatológico. El pronóstico está vinculado a la extensión local de la enfermedad y a la radicalidad de la extirpación quirúrgica. Presentamos un raro caso de CP hiperfuncionante con extensión mediastínica, enfatizando las dificultades diagnósticas, las características histopatológicas, las estrategias terapéuticas, a la luz de los más recientes datos de la literatura médica (AU)

Parathyroid carcinoma (PC) is an extremely rare malignancy, 0.005% of all tumours and between 0.5% and 5% of all parathyroid neoplasms. Preoperative diagnosis is often difficult and is almost always obtained only after post-surgical histopathology. The prognosis is related to the local extent of disease and to complete surgical resection of the tumour. We report an uncommon case of hyperfunctional PC with mediastinal extension, emphasising the diagnostic difficulties, histopathological features and treatment strategies. The most recent data in the literature is analysed as well (AU)

Hyperfunctional parathyroid carcinoma with mediastinal extension.

Parathyroid carcinoma (PC) is an extremely rare malignancy, 0.005% of all tumours and between 0.5% and 5% of all parathyroid neoplasms. Preoperative diagnosis is often difficult and is almost always obtained only after post-surgical histopathology. The prognosis is related to the local extent of disease and to complete surgical resection of the tumour. We report an uncommon case of hyperfunctional PC with mediastinal extension, emphasising the diagnostic difficulties, histopathological features and treatment strategies. The most recent data in the literature is analysed as well.

Human fibroblasts from normal and malignant breast tissue grown in vitro show a distinct senescence profile and telomerase activity.

The telomerase activity and the senescence profile of cultured breast fibroblasts from normal human interstitial and malignant stromal tissue were studied in comparison with their proliferation and differentiation pattern. Fibroblasts were grown either in the presence or absence of a conditioned medium (CM) obtained from cultures of the oestrogen receptor-positive breast cancer MCF-7 cell line. At different passages (from the 2nd up to the 48th), fibroblasts were examined for the telomerase activity by the Telomerase Repeats Amplification Protocol (TRAP) assay, for proliferation profile by Ki-67 antigen expression, and the myofibroblast or smooth muscle cell-like differentiation pattern by immunofluorescence with monoclonal antibodies specific for smooth muscle markers. Serial passages of fibroblasts from normal or tumour breast reveal that the relationship between the levels of telomerase activity and phenotypic/proliferation profile changes with cell subcultivation in a different manner in the two cell populations. The fibroblasts from normal tissue completed 12 passages in a CM-independent way prior to senescence whereas fibroblasts from tumour stroma senescence were attained after 48 passages. These cells showed a marked decrease of telomerase activity, growth rate and smooth muscle alpha-actin expressing myofibroblasts after the 32nd passage. CM treatment of this fibroblast population induces a decline in the myofibroblast content, which precedes the changes in telomerase activity. Passaged fibroblasts from normal breast tissue can be converted to myofibroblasts upon CM treatment whereas those from tumour stroma were CM-insensitive. Taken together our data suggest that a heterogeneous fibroblast population with different life span is activated/recruited in the breast interstitium and poses the problem of a unique activation/recruitment of fibroblasts in neoplastic conditions.