What's new in Ewing's tumor?

Ewing's tumor is an undifferentiated neoplasm that has eluded many attempts at classification since it was first described in 1919. Even modern techniques applied to the study of series of tumors with clinical and pathologic features of Ewing's tumor have not elucidated its histogenesis. Some of these studies conclude that the cell of origin of Ewing's tumor may be a noncommitted mesenchymal cell, but many other studies suggest a neuroectodermal differentiation and further results indicate a primitive, pluripotential cell for Ewing's tumor that may differentiate in mesenchymal, epithelial and neural features. Consequently, this tumor should be regarded as a blastoma.

Osteoblastoma and osteoid osteoma. Clinical and morphological features of 162 cases.

A study of 46 osteoblastomas and 91 osteoid osteomas, selected from a total of 162 cases proceeding from 15 Spanish Hospitals was done to establish epidemiological data on clinico-pathological parameters and to compare them with the findings of other authors. A comparative study between both tumors is done and emphasis is put on the discussion of aggressive osteoblastoma.

Papillary carcinoma of the thyroid with mucoepidermoid differentiation.

A case of papillary carcinoma of the thyroid with mucoepidermoid differentiation is reported. There have been different hypotheses of the histogenesis of this tumor, one of which attributes the origin of the tumor to the ultimobranchial body, mainly because of the presence of neuroendocrine markers. In our case, no neuroendocrine immunohistochemical markers were demonstrated, but a progressive transition between follicular cells and mucinous cells with gradual loss of thyroglobulin immunoreactivity and acquisition of polyclonal carcinoembryonic antigen reactivity was noted. Therefore, we propose that mucoepidermoid carcinoma may be a simple metaplastic transformation of a papillary carcinoma, because the thyroid glandular epithelium, which is of endodermal origin, is capable of differentiating easily into squamous, mucus-secreting, or even polypeptide-secreting epithelium.

[Granulomatous and allergic angiitis (Churg and Strauss). A case report (author's transl)]. / Angiitis granulomatosa y alérgica (Churg y Strauss). A propósito de un caso.

The autopsy findings in a case of granulomatous and allergic angiitis, or Chung and Strauss' disease, are reported. Certain uncommon peculiarities were seen during the course of the disease, such as the presence of multiple lymph nodes presumed from a clinical standpoint to be lymphomas. Its differential diagnosis from other forms of granulomatous vasculitis, especially from those which affect the lungs preferentially or exclusively, is discussed. Special consideration is given to the limited forms of Wegener's disease, which is surprisingly similar morphologically; its more significant differences lie in the clinical and topographic areas, rather than in morphology. The lymph nodes, presumed to be lymphomas from a clinical view-point, are a truly exceptional circumstances in this disease. In the author's opinion the histologic pattern clearly indicates that the etiopathogenesis lies in a congenital or acquired immune disturbance. The recent literature is review, while the present knowledge about the broad and confusing spectrum of these conditions --arteritis, and pulmonary granulomatosis-- is discussed.

[Eosinophilic enteritis with mucosal predominance and with a 4 years' course]. / Enteritis eosinofílica de predominio mucoso y cuatro décadas de evolución.

We report a case of eosinophilic enteritis without eosinophilia in a 42-year-old woman with symptoms presumably due to the disease since her childhood. We comment the clinical evolution after surgery and some anatomo-clinico and management features of this rare entity.

Pilomatrix carcinoma: role played by MR imaging.

We report the magnetic resonance imaging (MRI) of a pilomatrix carcinoma. We found a soft tissue tumor of the back entering the spinal canal and compressing the spinal cord and we monitored a good response to radiotherapy and chemotherapy. We have concluded that MRI played an important role in determination of the volume, extension and management of this rare malignant tumor.