Merkel cell carcinoma of the head and neck associated with Bowen's disease

Summary The Merkel cell carcinoma occurs primarily in the skin of the head and neck, and develops in the dermis with a trabecular growth pattern. Immunohistochemistry reveals positive staining for neuron-specific enolase, neurofilaments, cytokeratin and chromogranin A. Electron microscopically, the tumor cells contain dense-core granules, spinous cytoplasmic processes, desmosomes, zonulae adherentes and paranuclear filament aggregates besides frequent mitoses, focal necroses and lymphocyte and plasma cell infiltrates. The Merkel cell carcinoma is often co-existent with other malignancies such as squamous cell carcinoma or, as in the present study, with Bowen's disease. The definite diagnosis of the Merkel cell carcinoma can be effected only by electron microscopic examination of the tumor.Presented in part at the 62nd Annual Meeting of the German Society for Otorhinolaryngology, Head and Neck Surgery, May 14, 1991, Aachen, FRGDedicated to Prof. K. Burian on the occasion of his 70th birthday     

Holmium:YAG laser surgery. Possibilities for use in inflammatory paranasal sinus diseases]

A pulsed Holmium: YAG laser (lambda = 2120 nm) was used during functional endoscopic endonasal surgery in ten patients with recurrent chronic inflammation of the paranasal sinuses. The Holmium: YAG laser energy was coupled to a 600 microns core diameter nylon fiber. Power settings of 950 mJ per 2.5 microseconds pulse at 5 pulses per second were used. Tissue responses to treatment were examined by light microscopy. The photoablative mechanism of the laser-tissue interaction led to bone and soft tissue ablation with only a minor thermal component in the target zone. In comparison with other laser types available clinically, there was no carbonization zone after use of the Holmium-YAG laser. The area of tissue damage produced was significantly smaller (370-520 microns only) and wound healing proceeded without complication. The physical settings of the laser equipment are described with regard to their significance in photoablation when using flexible light-conducting fibers. The possible role of the Holmium: YAG laser in clinical surgery is discussed on the basis of the present experience.     

Four new sesquiterpenoid derivatives from the heartwood of Mansonia gagei

Four new sesquiterpenoid derivatives named mansonones N (1), O (2), P (3), and Q (4) were isolated from a dichloromethane extract of the heartwood of Mansonia gagei, a plant used in folk medicine in Thailand. Their structures were resolved on the basis of spectrometric data interpretation and the single-crystal X-ray analysis of 1 and 2.     

Chromosomal aberrations in benign and malignant Bilharzia-associated bladder lesions analyzed by comparative genomic hybridization

Background

Bilharzia-associated bladder cancer (BAC) is a major health problem in countries where urinary schistosomiasis is endemic. Characterization of the genetic alterations in this cancer might enhance our understanding of the pathogenic mechanisms of the disease but, in contrast to nonbilharzia bladder cancer, BAC has rarely been the object of such scrutiny. In the present study, we aimed to characterize chromosomal imbalances in benign and malignant post-bilharzial lesions, and to determine whether their unique etiology yields a distinct cytogenetic profile as compared to chemically induced bladder tumors.

Methods

DNAs from 20 archival paraffin-embedded post-bilharzial bladder lesions (6 benign and 14 malignant) obtained from Sudanese patients (12 males and 8 females) with a history of urinary bilharziasis were investigated for chromosomal imbalances using comparative genomic hybridization (CGH). Subsequent FISH analysis with pericentromeric probes was performed on paraffin sections of the same cases to confirm the CGH results.

Results

Seven of the 20 lesions (6 carcinomas and one granuloma) showed chromosomal imbalances varying from 1 to 6 changes. The most common chromosomal imbalances detected were losses of 1p21-31, 8p21-pter, and 9p and gain of 19p material, seen in three cases each, including the benign lesion.

Conclusion

Most of the detected imbalances have been repeatedly reported in non-bilharzial bladder carcinomas, suggesting that the cytogenetic profiles of chemical- and bilharzia-induced carcinomas are largely similar. However, loss of 9p seems to be more ubiquitous in BAC than in bladder cancer in industrialized countries.