Don Hoang

A strategy for the successful management of dermatofibrosarcoma protuberans.

BackgroundDermatofibrosarcoma protuberans (DFSP) is a rare, locally invasive soft tissue sarcoma with extensive subclinical involvement. The National Comprehensive Cancer Network guidelines recommend immediate reconstruction in most cases. Our study reviewed the methods of treatment of DFSP at our institution, examined the types of closure used after surgical excision, and analyzed the prevalence of positive margins on permanent pathology after immediate closure after conventional non-Mohs excision of DFSP. MethodsThe charts of 25 patients treated with surgical excision and 16 with Mohs surgery from 1990 to 2009 for lesions consistent with DFSP were reviewed for clinical variables including disease state, tumor site, closure type, permanent pathology margin status, disease recurrence/persistence, and excisional margin size. ResultsThe trunk, followed by the head and neck, were the most common sites for DFSP. No patients had distant metastasis at diagnosis or experienced recurrence in either the surgical excision or the Mohs surgery group. Twelve (48%) patients were found to have positive margins after initial surgical resection. All lesions treated with Mohs surgery had clear histological margins at completion. Average margin size for surgical excision patients was 2.33 cm (range, 0.75–4.5 cm), and 1.36 cm (range, 0.74–2.55 cm) for Mohs excision. The average duration of follow-up was 107.9 months. ConclusionsThe extent of DFSP is difficult to determine intraoperatively with traditional surgical excision, which leads to a higher rate of positive margins. Considering this difficulty and the complications of reconstruction with positive margins, we believe that reconstruction after tumor resection should be dependent on definitive pathologic clearance of the tumor.

Leptin Is Produced by Parathyroid Glands and Stimulates Parathyroid Hormone Secretion

Objective: We asked if leptin and its cognate receptor were present in normal and diseased parathyroid glands, and if so, whether they had any functional effects on parathyroid hormone (PTH) secretion in parathyroid neoplasms. Background: The parathyroid glands acting through PTH play a critical role in the regulation of serum calcium. Based on leptins recently discovered role in bone metabolism, we hypothesized these glands were the sites of a functional interaction between these 2 hormones. Methods: From July 2010 to July 2011, 96 patients were enrolled in a prospective study of leptin and hyperparathyroidism, all of whom were enrolled based on their diagnosis of hyperparathyroidism, and their candidacy for surgical intervention provided informed consent. Immediately after parathyroidectomy, 100 to 300 mg of adenomatous or hyperplastic diseased parathyroid tissue was prepared and processed according to requirements of the following: in situ hybridization, immunohistochemistry, immunofluorescence by conventional and spinning disc confocal microscopy, electron microscopy, parathyroid culture, whole organ explant, and animal model assays. Results: Leptin, leptin receptor (long isoform), and PTH mRNA transcripts and protein were detected in an overlapping fashion in parathyroid chief cells in adenoma and hyperplastic glands, and also in normal parathyroid by in situ hybridization, qRT-PCR, and immunohistochemistry. Confocal microscopy confirmed active exogenous leptin uptake in cultured parathyroid cells. PTH secretion in explants increased in response to leptin and decreased with leptin receptor signaling inhibition by AG490, a JAK2/STAT3 inhibitor. Ob/ob mice injected with mouse leptin exhibited increased PTH levels from baseline. Conclusions: Taken together, these data suggest that leptin is a functionally active product of the parathyroid glands and stimulates PTH release.

A novel cranioplasty technique incorporating cancellous femoral bone and recombinant bone morphogenic protein 2.

Abstract Large calvarial defects in the setting of chronic infection and limited autologous donor sites present challenging problems for the reconstructive surgeon. We report on a novel osteogenic implant as a potential calvarial reconstruction solution. Two patients with an extensive history of severe traumatic brain injury and multiple cranial operations desired delayed calvarial reconstruction subsequent to removal of infected acrylic and titanium implants. These patients underwent harvesting of cancellous femoral bone and bone marrow, which was placed between 2 layers of recombinant bone morphogenic protein 2 impregnated in acellular collagen sponges and an outer layer of sturdily pliable Vicryl mesh to create a moldable osteogenic implant construct. The construct was molded into the shape of the defect and secured with sutures to the skull surrounding the defect. The osteogenic implant showed evidence of bone formation and maintained coverage over the original calvarial defect at 26 months postoperatively as well as subjective satisfaction by both patients and the senior surgeon. This technically straightforward technique with acceptable functional and aesthetic outcomes may be useful to reconstructing selected calvarial defects.

Absence of aneuploidy and gastrointestinal tumours in a man with a chromosomal 2q13 deletion and BUB1 monoallelic deficiency.

Chromosomal instability is a potentially critical step in the development of colorectal cancer. The budding uninhibited by benzimidazole 1 (BUB1) gene is a highly conserved protein that plays a critical role at the spindle assembly checkpoint during cell division. BUB1 mutations function in a dominant-negative fashion and have been implicated in causing dysfunctional kinetochore attachments, premature chromatid separation, accelerated mis-segregation of whole chromosomes and aneuploidy. BUB1 mutations have been observed in patients with colorectal cancers. We report a remarkable case of BUB1 haploinsufficiency owing to a 1.7 Mb deletion of chromosome 2q13 in a 54-year-old man with no prior history of carcinoma. These mutant alleles were observed in both tissue from the hand and peripheral blood. Aneuploidy was not observed on cytogenetic analysis. These findings highlight the insufficiency of BUB1 haploinsufficiency to directly stimulate tumourigenesis, and suggest that other factors may be more critical to this process.

Knowledge and Perceptions of HIV-Infected Patients Regarding HIV Transmission and Treatment in Ho Chi Minh City, Vietnam

Patient education concerning HIV and antiretroviral (ARV) medications is important for optimal outcomes. The authors assessed the knowledge and perceptions of HIV-infected patients in an ARV education program in Ho Chi Minh City, Vietnam. Of 185 patients, 64 (35%) receiving ARV medications, nearly 80% correctly answered questions regarding HIV. Correct responses were associated with higher education (P < .05) and longer duration of HIV diagnosis (P < .05). A lack of knowledge was observed in 40% of respondents who believed HIV and AIDS were the same and 70% of respondents who believed ARV medications cured HIV. Greater embarrassment of living with HIV was associated with female gender (P < .05) and lower education (P < .05). Patients were concerned over ARV medication use (27%) and its side effects (38%). The study population’s knowledge of HIV/AIDS and ARV medications, perceived stigmatization, and areas of knowledge deficits underscore the need for effective patient education programs addressing poorly understood issues around HIV/AIDS.

Deepithelialized flap closure: an adjunct to complex ventral hernia repairs.

AbstractVentral hernias are a major surgical challenge with complications such as wound separations, infections, and recurrences contributing to patient morbidity. We describe a new adjunctive technique that may be helpful in repairing difficult ventral hernias: it involves using an appropriately chosen, redundant abdominal skin edge that is deepithelialized and used to reinforce the hernia repair. A series of 7 patients aged 23 to 84 years in whom the technique was used is presented. All patients had complete repair of their incisional ventral hernia defects without complications of infection, wound dehiscence, seroma formation, reoperation, or hernia recurrence. Furthermore, patients reported a subjective improvement in performing daily activities. Mean follow-up in this series was 19.2 months, with a range from 15.0 to 26.8 months. Advantages include the redistribution of mechanical tension, reinforcement of the midline site of greatest pressure, elimination of dead space, and staggering of suture lines to prevent direct external contamination of prosthetic material should wound dehiscence occur.