Soft tissue tumors of the penis - A review

Penile soft tissue tumors comprise 5% of tumors at this site and most have been reported as isolated case reports. The purpose of this review is to aid the practicing surgical pathologist in distinguishing penile soft tissue tumors, such as sarcomatoid squamous cell carcinoma, from other prognostically and therapeutically important entities in the differential diagnosis. Clinical presentation, management, prognosis and factors influencing behavior are reviewed. The immunohistochemical profiles and salient morphologic clues that may help distinguish penile spindle cell tumors from sarcomatoid carcinomas are evaluated. Soft tissue tumors of the penis may be classified as benign or malignant, as superficial or deep and in terms of age at presentation. All are rare. The most common benign soft tissue tumors that affect the penis are vascular neoplasms, followed by tumors of neural, myoid and fibrous origin. Among reported cases, the most frequent malignant penile soft tissue tumors are Kaposi sarcoma and leiomyosarcoma. Correctly diagnosing penile soft tissue tumors is imperative, because the biologic behavior and the clinical management of these neoplasms vary considerably. Distinguishing sarcomas from sarcomatoid carcinoma and melanoma is particularly important. Accurate diagnosis is best facilitated by consideration of all available aspects of the case, including clinical information, histopathologic findings and immunohistochemical results

New Findings in a Global Approach to Dissect the Whole Phenotype of PLA2G6 Gene Mutations.

Mutations in PLA2G6 gene have variable phenotypic outcome including infantile neuroaxonal dystrophy, atypical neuroaxonal dystrophy, idiopathic neurodegeneration with brain iron accumulation and Karak syndrome. The cause of this phenotypic variation is so far unknown which impairs both genetic diagnosis and appropriate family counseling. We report detailed clinical, electrophysiological, neuroimaging, histologic, biochemical and genetic characterization of 11 patients, from 6 consanguineous families, who were followed for a period of up to 17 years. Cerebellar atrophy was constant and the earliest feature of the disease preceding brain iron accumulation, leading to the provisional diagnosis of a recessive progressive ataxia in these patients. Ultrastructural characterization of patients' muscle biopsies revealed focal accumulation of granular and membranous material possibly resulting from defective membrane homeostasis caused by disrupted PLA2G6 function. Enzyme studies in one of these muscle biopsies provided evidence for a relatively low mitochondrial content, which is compatible with the structural mitochondrial alterations seen by electron microscopy. Genetic characterization of 11 patients led to the identification of six underlying PLA2G6 gene mutations, five of which are novel. Importantly, by combining clinical and genetic data we have observed that while the phenotype of neurodegeneration associated with PLA2G6 mutations is variable in this cohort of patients belonging to the same ethnic background, it is partially influenced by the genotype, considering the age at onset and the functional disability criteria. Molecular testing for PLA2G6 mutations is, therefore, indicated in childhood-onset ataxia syndromes, if neuroimaging shows cerebellar atrophy with or without evidence of iron accumulation

Transcriptional regulator PRDM12 is essential for human pain perception.

Pain perception has evolved as a warning mechanism to alert organisms to tissue damage and dangerous environments. In humans, however, undesirable, excessive or chronic pain is a common and major societal burden for which available medical treatments are currently suboptimal. New therapeutic options have recently been derived from studies of individuals with congenital insensitivity to pain (CIP). Here we identified 10 different homozygous mutations in PRDM12 (encoding PRDI-BF1 and RIZ homology domain-containing protein 12) in subjects with CIP from 11 families. Prdm proteins are a family of epigenetic regulators that control neural specification and neurogenesis. We determined that Prdm12 is expressed in nociceptors and their progenitors and participates in the development of sensory neurons in Xenopus embryos. Moreover, CIP-associated mutants abrogate the histone-modifying potential associated with wild-type Prdm12. Prdm12 emerges as a key factor in the orchestration of sensory neurogenesis and may hold promise as a target for new pain therapeutics