Východiska: Nádory slzného vaku jsou velmi vzácné a jsou často nerozpoznány, jelikož pacienti mají zdánlivě chronickou dakryocystitidu. Jako nejčastější se u nádorů slzného vaku uvádí karcinom dlaždicových buněk. Primární mukoepidermoidní karcinomy slzného vaku jsou vzácné a jsou popisovány jako lokálně agresivní. Navíc jejich blízkost životně důležitým strukturám a bazi lebeční je činí potenciálně život ohrožující. Doporučuje se multidisciplinární přístup se širokým vyříznutím s následnou chemoradiací. Případ: Popisujeme případ primárního mukoepidermoidního karcinomu slzného vaku u 65letého muže. Karcinom se projevoval slzením očí a přítomností hmoty v oblasti mediálního koutku, kterou se úspěšně podařilo odstranit radikální operací a rekonstrukcí. Nádor byl resekován pomocí rozšířeného Lynch-Howarthova řezu a defekt byl odstraněn za použití čelní klapky. Histopatologické vyšetření vyříznutého vzorku odhalilo mukoepidermoidní karcinom. Imunohistochemické barvení bylo pozitivní na EGFR (receptor pro epiteliální růstový faktor) a Ki-67 protein. Pacient byl po operaci odeslán k chemoradiaci. V tomto článku byla shrnuta literatura a jsou diskutovány patologické rysy vč. imunohistochemie. Závěr: Primární mukoepidermoidní karcinom slzného vaku je vzácný, lokálně agresivní nádor, který je často mylně považován za dakryocystitidu. Léčebnou modalitou je radikální operace a následně chemoradiace.
Background: Lacrimal sac tumors are very rare and are often missed because patients present with features consistent with chronic dacryocystitis. Squamous cell carcinoma is the commonest lacrimal sac malignancy. Although primary mucoepidermoid carcinomas of the lacrimal sac are rare, they are locally aggressive. Furthermore, their proximity to vital structures and the skull base makes them potentially life-threatening. Multidisciplinary management is required, and wide excision followed by chemoradiation is the recommended treatment. Case: Here, we report a 65-year-old male who presented with watering eyes and a mass in the region of the medial canthus. A diagnosis of primary mucoepidermoid carcinoma of the lacrimal sac was made, and the case was managed successfully with radical surgery and reconstruction. The tumor was resected using the extended Lynch-Howarth incision and the resulting defect was reconstructed using a forehead flap. Histopathological examination of the excised specimen revealed mucoepidermoid carcinoma. Immunohistochemical analysis revealed that the specimen was positive for epithelial growth factor receptor and Ki-67 protein. The patient was referred for post-operative chemoradiation. The literature is reviewed and pathological features, including immunohistochemistry are discussed. Conclusion: Primary mucoepidermoid carcinoma of the lacrimal sac is a rare, locally aggressive tumor that is often mistaken for dacryocystitis. The treatment of choice is radical surgery followed by chemoradiation.
- MeSH
- adjuvantní chemoradioterapie MeSH
- ductus nasolacrimalis * patologie MeSH
- imunohistochemie MeSH
- lidé MeSH
- mukoepidermoidní karcinom * diagnóza patologie terapie MeSH
- nádory oka diagnóza patologie terapie MeSH
- nemoci slzného ústrojí diagnóza patologie terapie MeSH
- oftalmologické chirurgické výkony MeSH
- senioři MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- Publikační typ
- kazuistiky MeSH
- přehledy MeSH
Summary Wild type human full length (f.1.) tumor suppressor p53 protein binds preferentially to super-coiled (sc) DNA in vitro both in the presence and absence of the p53 consensus sequence (p53CON). This binding produces a ladder of retarded bands on the agarose gel. Bands revealed by immunoblotting with antibody DO-1 corresponded to the ethidium stained retarded bands. The intensity and the number of bands of p53-scDNA complex were decreased by physiological concentrations of unchelated zinc ions. Nickel and cobalt ions inhibited binding of p53 to scDNA and to p53CON in linear DNA fragments less efficiently than zinc. Compared to the intrinsic zinc strongly bound to Cys 176, Cys 238, Cys 242 and His 179 in the p53 core domain, binding of additional Zn(2+) to p53 was much weaker as shown by an easy removal of the latter ions by low concentrations of EDTA. Oxidation of the protein with diamide resulted in a decrease of the number of the retarded bands. Under the same conditions, no binding of oxidized p53 to p53CON in a linear DNA fragment was observed. In agreement with the literature oxidation of f.1. p53 with diamide was irreversible and was not reverted by an excess of DTT. We showed that in the presence of 0.1 mM zinc ions, oxidation of p53 became reversible. Other divalent cations tested (cadmium, cobalt, nickel) exhibited no such effect. We suggested that the irreversibility of p53 oxidation was due, at least in part, to the removal of intrinsic zinc from its position in the DNA binding domain (after oxidation of the three cysteines to which the zinc ion is coordinated in the reduced protein) accompanied by a change in the p53 conformation. Binding of C-terminal anti-p53 antibody also protected bacterially expressed protein against irreversible loss of activity due to diamide oxidation. Binding the human p53 core domain (segment 94-312) to scDNA greatly differed from that observed with the full-length p53. The core domain did not posses the ability to bind strongly to many sites in scDNA regardless of the presence or absence of p53CON suggesting involvement of some other domain (probably C-terminal) in binding of the full-length p53 to scDNA. Supershift experiments using antibodies against p53 N- or C-terminus suggested that in oxidized p53, scDNA binding through the C-terminus gained importance.
- MeSH
- DNA nádorová MeSH
- nádorový supresorový protein p53 MeSH
- vazebná místa MeSH
- Publikační typ
- kongresy MeSH
