Placental membrane grafts for urethral replacement in a rabbit model: a pilot study.

PURPOSE: Several graft materials are available for use in the treatment of urethral stricture disease. Placental membrane is being used in a variety of settings as a graft in wound healing and tissue repair. We aim to evaluate the effect of implanting decellularized human placental membrane into rabbit urethras. METHODS: Dorsal onlay graft urethroplasty using prepared human placental membrane was performed in 10 New Zealand White rabbits (Oryctolagus cuniculus). After 3 months, the rabbits underwent cystourethroscopy to evaluate urethral patency. The rabbits were then euthanized and the urethras examined for pathological findings. RESULTS: All urethroplasties were performed without complication. There were no observed episodes of urinary retention, infection, or renal failure. Urethral patency was achieved in all rabbits 3 months postoperatively. Urothelial replacement of the placental membrane graft was observed in all rabbits without malignant transformation. CONCLUSION: Dorsal onlay urethroplasty using decellularized human placental membrane can safely be performed in a rabbit model. This pilot study demonstrated urothelial replacement of human placental membrane in the rabbit urethra without stricture formation. Placental membrane is a promising biomaterial for urethral reconstruction.

Hidradenocarcinomas: a brief review and future directions.

Hidradenocarcinomas are rare, aggressive skin adnexal tumors of sweat gland origin that demonstrate a high potential for local recurrence, metastasis, and poor outcome. These neoplasms can derive from preexisting clear cell hidradenomas but more commonly appear de novo, with the molecular events responsible for the pathogenesis currently unknown. Historically, diagnosis has been difficult because of the few cases, inconsistent nomenclature, variable morphology of cells that compose the neoplasm, and confusion with other visceral metastatic tumors. Presentation is generally benign with an indolent clinical course that typically includes local and multiple recurrences. Despite wide-excision surgery, disease at regional lymph nodes and metastatic sites is common and linked to decreased survival. Currently, molecular markers of pathogenesis as well as effective forms of adjuvant chemotherapy are lacking. Future studies are required to identify the histopathologic and immunohistochemical features, which may facilitate diagnosis and foster development of molecularly targeted forms of adjuvant therapy.

Mechanistic and Treatment Implications of DeltaNp63 Expression in a Rare Case of Metastatic Hidradenocarcinoma.

Hidradenocarcinomas are rare, aggressive adnexal tumors of sweat gland origin that demonstrate a high potential for local recurrence, metastasis and poor outcome. These neoplasms can derive from preexisting clear cell hidradenomas, but more commonly appear de novo with the molecular events responsible for the pathogenesis currently unknown. Molecular markers of pathogenesis as well as effective forms of adjuvant chemotherapy are missing due to the lack of accurate diagnosis, paucity of cases and confusion with other visceral solid tumors. Here, we report a 37-year-old man who presented with a rapidly growing, painful palpable mass located in the right inguinal area. The patient was a nonsmoker, did not consume alcohol and had a medical history remarkable only for a lower abdominal superficial skin lesion in the same area that had been excised 11 years earlier. Although initially slow growing, the lesion eventually expanded, was surgically excised and was diagnosed as a hidradenoma. There was no family history of malignancy and the patient had not experienced any constitutional symptoms. We probed the immunohistochemical status and detected negative staining for the estrogen, progesterone and Her2 receptors, while strong, diffuse nuclear staining was seen in the majority of cells consistent with p53 overexpression. Similarly, strong nuclear reactivity was seen with p63 and p73 antibodies. The p63 gene contains 2 separate promoters which express at least 6 major transcripts that lead to 2 fundamentally different classes of proteins; 3 isoforms (TAp63alpha, beta and gamma) encode proteins that induce apoptosis, whereas the other 3 isoforms (DeltaNp63alpha, beta and gamma) may exert inhibitory effects on p53. Interest in p63 stems from this 'two genes in one'-concept. Importantly, the nuclear presence of DeltaNp63 was detected widespread throughout the tumor. We have identified a subtype of hidradenocarcinomas that express DeltaNp63 and uncovered an unforeseen commonality with triple-negative breast tumors. To our knowledge, this is the first report of a sweat gland tumor that displayed expression of both DeltaNp63 and p73 and demonstrated a triple-negative receptor status. Such a link between 2 seemingly disparate tumor types indicates a mutual pathway of tumorigenesis and suggests the potential for common therapeutic regimens.