Elena Lucas

Comparative Effects of Irreversible Electroporation, Radiofrequency Ablation, and Partial Nephrectomy on Renal Function Preservation in a Porcine Solitary Kidney Model

OBJECTIVE To evaluate kidney function preservation or regeneration and pathological changes post-irreversible electroporation (IRE) in comparison with partial nephrectomy and radiofrequency ablation (RFA) in a solitary kidney porcine model. Tissue ablation using IRE has been reported to spare critical anatomic structures within or near the ablation zone with associated regeneration of adjacent parenchyma, possibly offering functional preservation. METHODS Fifteen pigs initially underwent laparoscopic nephrectomy. The lower third of the remaining kidney was then ablated or removed with either IRE, RFA, or partial nephrectomy. Serum creatinine (SCr) was measured at baseline, 24 hours, 3, 7, 14, and 28 days postoperatively. The impact of the type of procedure on SCr over time was evaluated. Acute and chronic histological changes were analyzed and cellular viability was assessed using nicotinamide adenine dinucleotide staining in the IRE ablations. RESULTS Ten ablations (5 IRE, 5 RFA) and 5 partial nephrectomies of the entire lower third of a solitary kidney were performed. The type of procedure did not affect SCr significantly at baseline (P = .14) or change in SCr over time (P = .48). Histologically, IRE and RFA lesions showed similar findings including coagulative necrosis that progressively was replaced by reparative stromal changes and fibrous tissue. Nicotinamide adenine dinucleotide staining of the IRE lesions at 14 and 28 days showed no viability in the necrotic areas with viable tissue at the margins demonstrating reparative changes. CONCLUSION Large volume IRE ablation of normal renal parenchyma in the porcine model does not provide a functional advantage as compared with conventional renal tumor treatments.

The diagnostic utility of Merkel cell polyomavirus immunohistochemistry in a fine needle aspirate of metastatic Merkel cell carcinoma of unknown primary to the pancreas

Merkel cell carcinoma (MCC) is an aggressive skin tumor with a high tendency for metastases. We report a case of MCC initially presenting as axillary and pancreatic metastases. A 33‐year‐old HIV‐positive Hispanic male presented with a history of a rapidly growing axillary mass. A needle core biopsy demonstrated an epithelioid neoplasm composed of small to medium‐sized cells with high nuclear‐cytoplasmic ratio, nuclear molding, and frequent mitotic figures. A subsequent PET scan revealed a 1.5 cm FDG avid mass in the pancreas. Endoscopic ultrasound‐guided FNA of the pancreatic mass showed neoplastic cells with similar morphology to those of the axillary mass. The tumor cells were positive with pancytokeratin AE1/AE3, CK20, CD56, synatophysin, chromogranin, and Merkel cell polyomavirus (MCPyV). This case of MCC most likely originated from a resolved primary skin lesion drained by the involved axillary lymph node with subsequent metastases to the pancreas and distant lymph nodes.

Metastatic Melanoma to the Bladder: Case Report and Review of the Literature.

A 49-year-old Caucasian woman presented to the dermatology clinic for follow-up of malignant melanoma with a complaint of painless gross hematuria. Two years prior she was diagnosed with malignant melanoma from a skin lesion on her left flank treated with wide excision, negative axillary sentinel lymph node biopsy, and adjuvant radiotherapy. Subsequently, she had no evidence of disease until urologic evaluation of her hematuria revealed two lesions in her bladder and cytopathology demonstrated findings consistent with malignant melanoma. We review literature on melanoma metastatic to the bladder and discuss the potential role of metastasectomy and other treatment strategies in such rare cases.

Superficially invasive cervical squamous cell carcinoma metastatic to ovarian endometriotic cyst wall, a case report and brief review of the literature

BackgroundAlthough cases of cervical squamous cell carcinoma metastatic to the ovary have been previously documented, we report the first case of superficially invasive squamous cell carcinoma metastatic to the ovary.Case presentationA 45-year-old woman with a two-year history of ovarian endometriosis confirmed by ultrasound underwent oophorectomy. On microscopic examination, a focus of malignant stratified epithelium, initially interpreted as transitional cell carcinoma, was identified within the endometriotic cyst wall. Examination of the hysterectomy specimen revealed superficially invasive squamous carcinoma of the cervix. In addition, two triploid, CD45-negative cells were detected during the analysis of the peripheral blood for circulating tumor cells (CTC). High-risk HPV was detected on the sections of endometriosis containing cancerous area by using hybrid capture 2 assay, supporting the diagnosis of metastatic squamous cell carcinoma originating from the uterine cervix.ConclusionThis is the first report of superficially invasive squamous cell carcinoma metastatic to the ovary. Such finding could be misdiagnosed as primary ovarian transitional cell carcinoma, squamous cell carcinoma originating from metaplastic epithelium within endometriosis, or squamous cell carcinoma arising in a teratoma.

Effect of Differing Parameters on Irreversible Electroporation in a Porcine Model

INTRODUCTION AND OBJECTIVE Irreversible electroporation (IRE) is a new ablative technology to treat small renal masses. We evaluated differed ablation settings on lesion size and temperature changes in a porcine model. MATERIALS AND METHODS After Institutional Animal Care and Use Committee approval, 36 laparoscopy-guided and 16 open ablations were performed on 13 domestic female pigs. Ablation parameters studied were voltage (1000 V/cm, 1500 V/cm, or 2000 V/cm), probe exposure (1.0 or 1.5 cm), and lesion size over time (survival) (0-, 7-, or 14 day). Temperature changes were monitored during open ablations with differed settings. Gross lesion size was measured, and histologic analysis with hematoxylin and eosin and nicotinamide adenine dinucleotide staining was performed. RESULTS The 1000 V/cm ablations had no gross or histologic lesions. A factorial analysis of variance demonstrated that day (p = 0.56), exposure (p = 0.33), and voltage (p = 0.06) did not demonstrate statistical significance for affecting lesion size. For 1.0 cm probe exposure, 2000 V/cm did more closely approximate expected lesion size (p = 0.02) compared with 1500 V/cm. While significance was not seen for 1.5 cm probe exposure, 2000 V/cm often exceeded expected lesion volume. Only 1 of 4 temperature sensors, located adjacent to one of the IRE probes, noted a significant increase with increased voltage. However, all maximum temperatures remained less than 70°C. CONCLUSIONS Variation in lesion volume was seen with different ablation settings in this porcine model. Maximal energy and probe exposure settings should be utilized to ensure full coverage of target volume/mass, potentially without concern for thermal injury to renal collecting system or nearby structures.

Mimickers of Lung Carcinoma in Cytology and Small Biopsy Specimens

Various nonneoplastic processes and benign tumors can simulate lung cancer at different levels of diagnostic work-up: during physical examination, interpretation of radiologic images, or examination of pathologic material. Despite the advances in imaging studies, radiologic findings at times can be misleading due to an overlap in the appearance between neoplastic and nonneoplastic lesions. Cytologic evaluation and small tissue biopsy have become established initial methods for the evaluation of radiographically detected lung lesions. These methods are less invasive compared to video-assisted thoracic surgery, thoracotomy, and mediastinoscopy. However, specimens obtained from these methods are smaller than those obtained from the invasive procedures and can occasionally pose diagnostic challenges potentially resulting in misdiagnosis. Therefore, familiarity with the potential mimickers of lung carcinoma is of utmost importance.