Hamartoma quístico foliculosebáceo / Folliculosebaceous cystic hamartoma

El hamartoma quístico foliculosebáceo (FQH) es un tumor cutáneo benigno infrecuente, compuesto de unidades foliculosebáceas asociadas con elementosmesenquimales.Presentamos el caso de una mujer de 39 años con FQH, en el que se observó la presencia de un tallo piloso en uno de los quistes.Discutimos el diagnóstico diferencial histopatológico del FQH y la relación citogenética con el tricofoliculoma (AU)

Folliculosebaceous cystic hamartoma (FQH) is a rare cutaneous benign tumour, composed of dilated folliculosebaceous units associated with mesenchymalelements.We report a 39-year-old woman with a FCH presenting a hair shaft fragment in a cyst.We discuss the histopathological differential diagnosis of FCH and the histogenetic relantionship with trichofolliculoma (AU)

[Ectopic ovarian pregnancy]. / Embarazo ectópico ovárico.

Ovarian ectopic pregnancy is a rare form of ectopic pregnancy, with an estimated incidence ranging from 0.5% to 3% of the extrauterine pregnancies. For a correct diagnosis of the ovarian pregnancy, the traditional criteria proposed by Spiegelberg in 1878 must be fulfilled. This forced us sometimes to reject pregnancies which, despite being initially ovarian, during its evolution the adjacent tubal structures have been affected. Currently, the ectopic pregnancies are being diagnosed more early, mainly given the echographic advances, which have lead to very conservative treatments in order to avoid a reduced fertility. However, it is many times an intraoperative diagnosis. We present four new cases of ovarian ectopic pregnancy from our casuistry of the last three years with anatomoclinical study and literature review.

[Postoperative fusiform cell nodule. Relationship with other benign fibrous proliferations]. / Nódulo de células fusiformes postquirúrgico. Relación con otras proliferaciones fibrosas benignas.

We report on a patient who developed postoperative spindle cell nodule one month following TURP for prostatic adenocarcinoma. The foregoing was compared with other benign fibrous lesions from our records: one case of nodular fasciitis and one case of proliferative myositis. Although they were all well-defined and clinically distinct disease entities, a very close relationship concerning their origin was demonstrated histologically and immunohistochemically.

[An undifferentiated neuroendocrine carcinoma of the rectum with cervical metastases]. / Carcinoma indiferenciado neuroendocrino de recto con metástasis cervicales.

Sigma undifferentiated carcinoma of the rectum is a neuroendocrine tumor embracing less than 1% of all primary malignant epithelial tumors in this location. Recent studies have demonstrated that these tumors are biologically aggressive neoplasias with early metastatic extension. We present one case of loco-regional invasion at the time of the intervention and with distal metastasis within a period of time shorter than one year. We perform a clinical, histological and immunohistochemical study and we comment on the histogenesis of these tumors, their prognosis and treatment, stressing the need of an early diagnosis, an aggressive treatment and an adequate follow-up.

[Congenital mesoblastic nephroma in an adult: immunohistochemical study]. / Nefroma mesoblástico congénito en el adulto: estudio inmunohistoquímico.

A case of congenital mesoblastic nephroma in a 60-year-old female patient is described. The clinical onset was gross hematuria of 48 hours evolution and pain in the right renal fossa which irradiated to the iliac fossa of the same side. A routine pathological analysis was carried out on the surgical specimen including an extensive immunohistochemical analysis which was highly positive for keratin in the epithelial lining of the tubular and cystic structures and for desmine and vimentin in the fusocellular stroma of the tumor. The different histogenetic hypotheses are discussed. The importance of a precise anatomopathological diagnosis in order to institute adequate treatment is underscored.

Thymic carcinosarcoma associated with a spindle cell thymoma: an immunohistochemical study.

A case of thymic carcinosarcoma associated with a spindle cell thymoma in a 71-year-old woman is reported. Histological and immunohistochemical studies of the carcinosarcoma showed two quite different components: the sarcomatous component included cells with myoid differentiation which stained for desmin and muscle specific actin, and some isolated cells which stained positively for low molecular weight cytokeratin, while the carcinomatous component, which formed less than 10% of the tumour, showed an epithelial phenotype, being positive for low and high molecular weight cytokeratin and epithelial membrane antigen. The thymoma cells showed epithelial markers, and a few cells were also positive for desmin and muscle specific actin. The rarity of this tumour and its possible histogenesis are discussed.

[Undifferentiated small-cell carcinoma of the urinary bladder]. / Carcinoma indiferenciado de células pequeñas de vejiga urinaria.

We report a case of undifferentiated small cell carcinoma of the urinary bladder in a 64-year-old male patient. Microscopically the tumor was similar to the intermediate type of small cell carcinoma of the lung, with some foci of transitional papillary carcinoma, adenocarcinoma and carcinoma in situ. Small cell carcinoma is seldom encountered in the urinary bladder. It is more aggressive and must be distinguished from poorly differentiated transitional cell carcinoma.