An endolymphatic sac tumor (ELST) is a very uncommon papillary epithelial neoplasm arising within the endolymphatic sac or endolymphatic duct. This tumor shows a very high association with Von Hippel–Lindau syndrome (VHL). Classification
The ELST has been referred to as adenocarcinoma of endolymphatic sac, Heffner tumor, papillary adenomatous tumor, aggressive papillary adenoma, invasive papillary cystadenoma, and papillary tumor of temporal bone. However, these names are not encouraged as they do not accurately classify the current understanding of the tumor. Signs and symptoms
Patients with ELST may present clinically with progressive or fluctuating, one sided sensorineural hearing loss which may mimick Ménières disease due to the development of tumor associated endolymphatic hydrops. Patients may also experience tinnitus, vertigo, and loss of vestibular function (ataxia). Alternatively, symptom onset may be sudden, due to intralabyrinthine hemorrhage. Patients may also present with other symptoms related to von Hippel–Lindau syndrome in other anatomic sites, which will result in imaging evaluation of the head. Imaging findings
Imaging studies help to identify the tumor and the specific anatomic site of involvement. Magnetic resonance images show a hyperintensity (hypervascularity) of a heterogeneous mass by T1 weighted images. Computed tomography shows a multilocular, lytic destructive temporal bone mass, centered on the vestibular aqueduct (between internal auditory canal and sigmoid sinus). Pathogenesis
The von Hippel–Lindau tumor suppressor gene generally has a germline mutation. This suppressor gene is also called elongin binding protein and G7 protein. The VHL protein is involved in up-regulation of hypoxic response via the [[hypoxia inducible factor [HIF]-1 alpha]].
When using over-the-counter drug clotrimazole products, use should be discontinued if condition does not improve after treatment for 2 weeks for jock itch or after 4 weeks for athletes foot or ringworm.Throat lozenge preparations are used for oropharyngeal candidiasis (oral thrush) or prevention of oral thrush in people with neutropenia.Clotrimazole is usually used five times daily for 14 days for oral thrush, twice daily for 2 to 8 weeks for skin infections, and once daily for 3 or 7 days for vaginal infections.Clotrimazole may be compounded with a glucocorticoid, such as betamethasone, in a topical cream for the treatment of tinea corporis (ringworm), tinea cruris (jock itch) and tinea pedis (athletes foot). Although FDA approved, clotrimazole–betamethasone combination cream is not the preferred treatment for dermatophyte infections due to increased side effects from the topical glucocorticoid.Although temporary relief and partial suppression of symptoms may be observed with the combination therapy, glucocorticoids can elicit an immunosuppressive response and rebound effect that results in more severe infection typically requiring systemic antifungal agents to treat the disease. Combination creams are best avoided in order to improve treatment outcome, reduce the possibility of skin atrophy associated with prolonged topical glucocorticoid use, and to limit the cost of treatment. It can be effective in treating chronic paronychia. The preferred treatment of tinea infections is therefore with clotrimazole monotherapy.Topical and oral clotrimazole can be used in both adults and children.