Positive margins in excised dermatofibrosarcoma protuberans: a study of 58 cases treated with slow-Mohs surgery

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is characterized by unpredictable subclinical extension, meaning that positive margins are frequently detected following conventional surgical excision.

OBJECTIVE

To study the presence or absence of residual tumour in DFSP with positive margins after conventional surgery and identify possible predictors of residual tumour or clear margins following a single Mohs micrographic surgery (MMS) stage.

METHODS

A retrospective study of patients with DFSP and positive margins following conventional excision referred for MMS was performed. We studied gender, age, tumour site, time from presentation to diagnosis, and affected margins.

RESULTS

We studied 58 cases, 35 (60.3%) of which had histological evidence of residual tumour. Tumours of the head and neck were significantly associated with the persistence of tumour. A single MMS stage was sufficient to achieve clearance in the majority of cases (n = 46). All tumours with lateral involvement only were resolved with a single Mohs stage.

CONCLUSIONS

DFSPs with positive margins after conventional surgical excision should undergo re-excision because the majority have histologic evidence of residual tumour. Re-excision with 1-cm margins beyond the scar could be an option in certain tumour sites, particularly when it is known which margins are involved.

Fast and stable recording of birefringence and holographic gratings in an azo-polymethacrylate using a single nanosecond light pulse

Pulsed light-induced recording in azobenzene polymers has recently been studied due to its potential use in optical storage applications. In this paper we study the photoinduced birefringence (Deltan) and holographic grating recording in an azobenzene side chain liquid-crystalline polymethacrylate irradiating with a single 4 ns light pulse at 532 nm. For some irradiation conditions, Deltan grows in less than 50 ns reaching an essentially stable value of about 10(-2). Holographic gratings have been registered using intensity and polarization patterns. Fast response and stability, similar to those of Deltan, was observed in the holographic recording process. Both light-induced anisotropy and relief contributions have been found in the case of gratings recorded using intensity patterns, relief being the dominant contribution at high recording energies. Polarization gratings have been recorded using two orthogonally circularly polarized beams. The resultant gratings showed stable efficiencies up to 0.8% (measured at 633 nm in 1-mum-thick films) and no measurable relief was observed.

Tetrathiafulvalene derivatives as NLO-phores: synthesis, electrochemistry, Raman spectroscopy, theoretical calculations, and NLO properties of novel TTF-derived donor-pi-acceptor dyads

Novel pi-conjugated donor-acceptor chromophores, based on the strong electron-donating tetrathiafulvalene moiety and different electron-withdrawing acceptors, exhibit large second-order optical nonlinearities. The effect of increasing the length of the polyenic spacer and the influence of the nature of the acceptor moiety on the NLO properties have been studied by using the electric field-induced second-harmonic generation (EFISH) technique as well as by semiempirical and ab initio theoretical calculations. A charge-transfer band has been observed in the absorption spectra of these D-pi-A compounds that undergoes an hypsochromic shift when increasing the number of vinylenic spacer units connecting both donor and acceptor moieties. The degree of the intramolecular charge transfer from the donor to the acceptor has also been analyzed by means of Raman spectroscopy.

Brucellar prosthetic arthritis in a total knee replacement

The infecting pathogens most commonly implicated in prosthetic joint infections are staphylococci, streptococci, and gram-negative rods. Prosthetic infections caused by Brucella spp. are rarely described in the literature. Treatment of prosthetic infections remains complex and controversial, the most accepted course being antibiotic treatment with removal or retention of prosthetic components. The case of a 60-year-old man who developed Brucella septic arthritis of the right knee in a total knee replacement is reported. Conservative treatment using a three-drug therapy was employed, with excellent results.