[Neuroendocrine tumor associated with an intestinal cyst: a case report].

Intestinal (tailgut) cysts or retrorectal cystic hamartomas are rare benign lesions that are included in the category of developmental cystic lesions. Their origin is still uncertain, although several hypotheses have been proposed to explain their development. They are located mainly in the presacral (retrorectal) space and predominately affect middle-aged women (40-60 years).

[TFEB-amplified renal cell carcinoma. A case report and review of the literature].

Renal carcinomas associated with translocation of transcription factors of the MiT/TFE family include, according to the latest World Health Organization classification, carcinomas with Xp11 translocation that involve the TFE3 gene and those with translocation t(6;11)(p21;q12) that affect the TFEB gene. Each one of these sub-types have well-defined clinicopathological and molecular characteristics. Currently, progress in molecular techniques has led to the description of neoplasms with molecular changes in these same genes but with alterations different to translocation.

[Pseudomyogenic hemangioendothelioma in the upper limb: A case report and literature review].

Pseudomyogenic hemangioendothelioma, also called epithelioid sarcoma-like hemangioendothelioma, is a rare, vascular neoplasm usually with indolent behaviour. It was introduced in the latest World Health Organization (WHO) Classification of Tumours of Soft Tissue. We report a case of a 45 year-old patient presenting with a localized, palpable and slightly painful lesion in the left arm.

Toxic epidermal necrolysis in polymedicated patient treated with radiotherapy.

Temozolomide is an oral alkylating agent indicated for the treatment of patients with glioblastoma multiforme concomitantly with radiotherapy and subsequently as monotherapy treatment. We report the case of a patient who developed toxic epidermal necrolysis (TEN) while she was being treated with chemoradiotherapy and several drugs. Cutaneous tests were performed with the drugs involved with negative result.

Old and new immunohistochemical markers for the diagnosis of gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GISTs) are generally CD117-positive and KIT or PDGFRA mutation-driven mesenchymal tumors of the gastrointestinal tract, probably originating in interstitial cells of Cajal or related precursors. CD117 is the best diagnostic marker for GISTs, but 5-10% are negative. Staining pattern may be cytoplasmic, membrane, and paranuclear (Golgi pattern).

Gastrointestinal stromal tumors: morphological, immunohistochemical and molecular changes associated with kinase inhibitor therapy.

Recurrent or metastatic GISTs are currently treated with kinase inhibitors since they achieves disease control in 70-85% of patients but this response depend on KIT and PDGFRA gene mutation status. We review the morfological and molecular findings associated to kinase inhibitors administration in GISTs based on the literature on Medline and authors' own experience. The initial response to kinase inhibitors (imatinib mesylate, Gleevec, Novartis) usually is partial and depend on the mutational KIT or PDGFRA state.

Primary testicular lymphoma with extranodal involvement.

Unlabelled: We report the case of a 65-year-old man who presented with a right testicular mass and synchronous involvement of skin and Waldeyer's ring. These facts led us to the working diagnosis of malignant primary testicular lymphoma.

Material/results: We present the case with comments and make a bibliographic review of the disease.

[Testicular choriocarcinoma with pure histological pattern. Necropsy study in a representative case].

Objective: Pure testicular choriocarcinoma is a relatively infrequent neoplasia with an ominous prognosis.

Methods: We report the necropsy study of a 21-year old male patient with generalized metastases of a primary pure testicular choriocarcinoma.

Results: The aggressiveness of this neoplasia is demonstrated by extensive tumor dissemination in early stages, in which testicular clinical manifestations are often absent.

Granular cell atypical fibroxanthoma: report of two cases.

Two cases of an uncommon histopathological variant of atypical fibroxanthoma (AFX) are described. Even though both lesions presented as clinically conventional atypical fibroxanthoma, histopathology disclosed a neoplasm composed of cells with granular change that was negative for S100 staining, and showed prominent pleomorphism, severe nuclear atypia, and a high mitotic index. Degenerative change may explain the granular phenotype in these two cases of AFX.