[An Undeniable Case of Optic Neuropathy Due to Cabazitaxel].

Cabazitaxelis a taxane-type antineoplastic agent used for treating prostate cancer. Although typical side effects include neutropenia and fatigue, no studies have investigated eye disorders as a possible side effect, and the details are not clear. Herein, we report our experience of an undeniable case of optic neuropathy caused by cabazitaxel. A 78-year-old man had been diagnosed with prostate cancer (cT3aN1M1b, stage IV) 3 years previously, with a treatment history of bicalutamide, leuprorelin, flutamide, docetaxel, abiraterone, and enzalutamide. Because of a decline in vision during the second and third administration cycles of cabazitaxel, the patient visited an ophthalmologist. He was found to have reduced visual acuity, reduced central critical flicker frequency, narrowed field of vision, and impaired color vision, and was diagnosed with optic neuropathy. Although cabazitaxel administration was continued through 6 cycles, the symptoms were unchanged, and no drastic exacerbation was seen. This patient undeniably developed optic neuropathy due to cabazitaxel. Optic neuropathy due to taxane-type antineoplastic agents has also been reported with paclitaxel or docetaxel, and all precautions should be taken when administering such drugs. Detailed studies that include data from a larger number of facilities should be conducted in the future.

MALIGNANT MESOTHELIOMA OF THE TUNICA VAGINALIS TESTIS: A CASE REPORT.

We report here a case of malignant mesothelioma of the tunica vaginalis testis. A 93-year-old man with no history of asbestos exposure complained of increase of right scrotum size with pain. Ultrasonography and magnetic resonance imaging revealed a right hydrocele testis. A cytologic examination of the hydrocele fluid demonstrated mesothelial cells but show less atypicality and lack of obvious malignant features (class IIIa). We performed right hydrocelectomy for hydrocele testis. The pathological diagnosis was epithelial type of malignant mesothelioma of the tunica vaginalis testis, therefore we performed radical orchidectomy with wide excision of hemi-scrotal wall. There is no evidence of recurrence after 6 months of follow up. Malignant mesothelioma of the tunica vaginalis is rare, and accurate preoperative diagnosis is difficult. When a rapid increasing hemorrhagic hydrocele testis or nodular masses of the tunica vaginalis was observed, malignant mesothelioma should be considered. Malignant mesothelioma is highly fatal disease. Even two stage operation, radical orchidectomy should be performed.

A differential ligand-mediated response of green fluorescent protein-tagged androgen receptor in living prostate cancer and non-prostate cancer cell lines.

Androgen has been shown to promote the proliferation of prostate cancer through the action of the androgen receptor (AR). Mutation (T877A) of the AR gene found in an androgen-sensitive prostate cancer cell line, LNCaP, has been postulated to be involved in hypersensitivity and loss of specificity for androgen. In the present study, trafficking of AR and AR (T877A) in living prostate and non-prostate cancer cell lines under high and low concentrations of androgen and antiandrogen was investigated by tagging green fluorescent protein (GFP) to the receptors. In the presence of a high concentration of androgen, AR-GFP localized in the nucleus by forming discrete clusters in all cell lines. AR (T877A)-GFP was also translocated to the nucleus in LNCaP and COS-1 cells by the addition of a high concentration of androgen. In contrast, in the presence of a low concentration of androgen, the translocation of AR-GFP and AR (T877A)-GFP was observed in LNCaP cells, but not in COS-1 cells. Upon the addition of antiandrogen, AR-GFP was translocated to the nucleus but did not form subnuclear foci in both COS-1 and LNCaP cells, whereas AR (T877A)-GFP in both cells was translocated to the nucleus with subnuclear foci. The present study demonstrates the differential response of nuclear trafficking of AR and its mutant in prostate cancer cell lines and COS cells, and the subcellular and subnuclear compartmentalization provide important information on the sensitivity of the AR mutation.