Composite hemangioendothelioma and its classification as a low-grade malignancy.

Hemangioendotheliomas are vascular neoplasms occupying a spectrum of biological potential ranging from benign to low-grade malignancy. Composite hemangioendothelioma (CH) is one of the less commonly encountered variants exhibiting a mixture of elements of other hemangioendothelioma subtypes, such as epithelioid, retiform, and spindle cell. Some authors have identified areas histopathologically equivalent to angiosarcoma within CH, raising the question of the true nature of this neoplasm.

KRAS Testing: A Tool for the Implementation of Personalized Medicine.

Activating point mutations in codons 12, 13, and 61 of the KRAS proto-oncogene are common in colorectal, non-small cell lung, pancreatic, and thyroid cancers. Constitutively activated KRAS mutations are strongly associated with a resistance to anti-epidermal growth factor receptor (EGFR) therapies, such as panitumumab and cetuximab used for treating metastatic colorectal carcinoma and EGFR tyrosine inhibitors used for advanced non-small cell lung cancers. Since anti-EGFR therapies are costly and may exert deleterious effects on individuals without activating mutations, KRAS mutation testing is recommended prior to the initiation of anti-EGFR therapy for these malignancies.

The histogenic origin of melanoma arising in respiratory epithelium of a teratomatous germ cell tumor of the mediastinum: an enigma unraveled from an unlikely source.

Mixed germ cell tumors are rare neoplasms that are known to occur in the anterior mediastinum. Characterized by two or more types of germ cell components, these tumors comprise upwards of 25% of mediastinal germ cell tumors. Even rarer are those harboring somatic-type malignancies such as carcinoma, sarcoma, and hematopoietic malignancies.

Rhabdomyomatous differentiation in Wilms tumor pulmonary metastases: a case report and literature review.

While sparsely reported in the literature, Wilms tumor may differentiate into more mature mesenchymal tissue types, such as skeletal muscle, following chemotherapy. The frequency of this event is unknown. Chemotherapy and radiation may induce cytodifferentiation of Wilms tumor cells or select for the survival of less mitotically active cells.

Primary cutaneous CD30+ T-cell lymphoproliferative disorder presenting as paraphimosis: a case report and review of the literature.

Primary cutaneous CD30+ T-cell lymphoproliferative disorders (PC-CD30+ LPD) as a group are one of the more common types of T-cell lymphoma. More specifically primary cutaneous anaplastic lymphoma (PC-ALCL), one of these lymphoproliferative disorders, is the second most common cutaneous T-cell lymphoma. We report an unusual presentation of PC-ALCL.

Potential utility of CD5 immunohistochemical staining in the diagnosis of muscle tumors.

CD5 is a 67 KD glycoprotein receptor that is present on a variety of T lymphocytes and mantle zone lymphocytes and is used routinely for the diagnosis of lymphomas and thymic carcinomas. That CD5 may be useful in diagnosis of mesenchymal tumors was an incidental finding in our sarcoma practice. This pilot study evaluated CD5 expression in benign and malignant muscle tumors in comparison to normal muscle.