Cystic angiosarcoma of the liver. A previously undescribed neoplasm.

 We report an example of a cystic hepatic angiosarcoma that to our knowledge has not been previously described. The patient was a 70 year old woman who was admitted to the emergency room because of hypovolemic shock. A computed tomography showed four heterogeneous hepatic cystic masses varying from 2.5 to 11.2 cm; one of these with rupture and formation of a subcapsular hematoma. The cyst wall was lined by several layers of neoplastic epithelioid and spindle shaped endothelial cells that in some areas extended to the underlying stroma. They expressed CD31 and CD34, and were negative for cytokeratin. The patient is alive with residual hepatic cystic angiosarcoma. However, follow up is too short to be significant.

An unusual type of biliar cyst: A case report.

 We present the case of a 56-yr-old woman with vague abdominal pain of approximately 5 months duration. An ultrasound study showed moderate dilation of the common bile duct. Magnetic resonance cholangiopancreatography confirmed a cystic dilatation of the right hepatic duct with intra and extra hepatic component. The patient underwent right hepatectomy and complete excision of the cyst. Microscopically, the cyst wall was formed by fibrous tissue with mild acute and chronic inflammatory infiltrate, the inner surface showed a single layer of columnar epithelium and extensive squamous metaplasia without atypia, wich expressed p63 and high molecular weight cytoqueratin (34BE12).

Histopathological transformation to small-cell lung carcinoma in non-small cell lung carcinoma tumors.

Lung cancer is the principal cause of cancer-related death worldwide. The use of targeted therapies, especially tyrosine kinase inhibitors (TKIs), in specific groups of patients has dramatically improved the prognosis of this disease, although inevitably some patients will develop resistance to these drugs during active treatment. The most common cancer-associated acquired mutation is the epidermal growth factor receptor (EGFR) Thr790Met (T790M) mutation. During active treatment with targeted therapies, histopathological transformation to small-cell lung carcinoma (SCLC) can occur in 3-15% of patients with non-small-cell lung carcinoma (NSCLC) tumors. By definition, SCLC is a high-grade tumor with specific histological and genetic characteristics. In the majority of cases, a good-quality hematoxylin and eosin (H&E) stain is enough to establish a diagnosis. Immunohistochemistry (IHC) is used to confirm the diagnosis and exclude other neoplasia such as sarcomatoid carcinomas, large-cell carcinoma, basaloid squamous-cell carcinoma, chronic inflammation, malignant melanoma, metastatic carcinoma, sarcoma, and lymphoma. A loss of the tumor-suppressor protein retinoblastoma 1 (RB1) is found in 100% of human SCLC tumors; therefore, it has an essential role in tumorigenesis and tumor development. Other genetic pathways probably involved in the histopathological transformation include neurogenic locus notch homolog (NOTCH) and achaete-scute homolog 1 (ASCL1). Histological transformation to SCLC can be suspected in NSCLC patients who clinically deteriorate during active treatment. Biopsy of any new lesion in this clinical setting is highly recommended to rule out a SCLC transformation. New studies are trying to assess this histological transformation by noninvasive measures such as measuring the concentration of serum neuron-specific enolase.