Acral and digital angioleiomyomata: 14-year experience at the Cleveland Clinic and review of the literature.

BACKGROUND: Angioleiomyoma is a benign neoplasm thought to derive from the tunica media of small venous vessels. Angioleiomyomata most frequently occur in the lower extremities with less common occurrences on the trunk, head and upper extremities. Few cases of acral and digital angioleiomyoma have been described in the literature. METHODS: We add a series of 21 patients with acral angioleiomyoma including 6 cases of digital angioleiomyoma to the body of clinical and histological findings along with a review of the literature of digital angioleiomyomata. RESULTS: Digital angioleiomyoma are equally distributed between male and female patients and are more often painful than the angioleiomyoma of all body sites. Acral angioleiomyomata favor the feet over hands at a ratio of 2.5:1, while digital angioleiomyoma favor the fingers over toes at a ratio of 4.3:1. CONCLUSIONS: We suggest that vascular leiomyoma be included in the differential diagnosis of smooth muscle tumors with particular regard to the digits of both the hands and the feet. Digital angioleiomyomata differ from acral angioleiomyomata in their equal gender distribution, increased tendency to cause pain and preponderance for the fingers over the toes.

Cytokeratin 20-negative Merkel cell carcinoma is infrequently associated with the Merkel cell polyomavirus.

Merkel cell carcinoma is a rare, highly aggressive cutaneous neuroendocrine carcinoma most commonly seen in sun-damaged skin. Histologically, the tumor consists of primitive round cells with fine chromatin and numerous mitoses. Immunohistochemical stains demonstrate expression of neuroendocrine markers. In addition, cytokeratin 20 (CK20) is expressed in ∼95% of cases. In 2008, Merkel cell carcinoma was shown to be associated with a virus now known as Merkel cell polyomavirus in ∼80% of cases. Prognostic and mechanistic differences between Merkel cell polyomavirus-positive and Merkel cell polyomavirus-negative Merkel cell carcinoma may exist. There has been the suggestion that CK20-negative Merkel cell carcinomas less frequently harbor Merkel cell polyomavirus, but a systematic investigation for Merkel cell polyomavirus incidence in CK20-negative Merkel cell carcinoma has not been done. To test the hypothesis that Merkel cell polyomavirus is less frequently associated with CK20-negative Merkel cell carcinoma, we investigated 13 CK20-negative Merkel cell carcinomas from the files of the Cleveland Clinic and the University of Michigan for the virus. The presence or absence of Merkel cell polyomavirus was determined by quantitative PCR performed for Large T and small T antigens, with sequencing of PCR products to confirm the presence of Merkel cell polyomavirus. Ten of these (77%) were negative for Merkel cell polyomavirus and three (23%) were positive for Merkel cell polyomavirus. Merkel cell polyomavirus is less common in CK20-negative Merkel cell carcinoma. Larger series and clinical follow-up may help to determine whether CK20-negative Merkel cell carcinoma is mechanistically and prognostically unique.

Job Performance as Multivariate Dynamic Criteria: Experience Sampling and Multiway Component Analysis.

Questions about the dynamic processes that drive behavior at work have been the focus of increasing attention in recent years. Models describing behavior at work and research on momentary behavior indicate that substantial variation exists within individuals. This article examines the rationale behind this body of work and explores a method of analyzing momentary work behavior using experience sampling methods. The article also examines a previously unused set of methods for analyzing data produced by experience sampling. These methods are known collectively as multiway component analysis. Two archetypal techniques of multimode factor analysis, the Parallel factor analysis and the Tucker3 models, are used to analyze data from Miner, Glomb, and Hulin's (2010) experience sampling study of work behavior. The efficacy of these techniques for analyzing experience sampling data is discussed as are the substantive multimode component models obtained.