Timothy S. Loy

Primary small-cell carcinoma of the esophagus : report of 11 cases and review of the literature

Primary small-cell carcinoma of the esophagus is an uncommon esophageal malignancy. This report details the clinical and pathologic aspects of 11 cases seen at our institution over 20 years, as well as 123 other cases reported in the literature. Small-cell carcinomas of the esophagus show considerable histologic heterogeneity. Neurosecretory granules can be found in the majority of cases and some show evidence of multidifferentiation. Like primary small-cell cancers of the lung, those in the esophagus are highly aggressive, are usually associated with spread at the time of diagnosis, and have a dismal prognosis regardless of treatment. The possible origin of this interesting variety of esophageal neoplasm is also discussed.

Method of preparing a decellularized porcine tendon using tributyl phosphate

Extracellular matrix (ECM) materials are currently utilized for soft tissue repair applications such as vascular grafts, tendon reconstruction, and hernia repair. These materials are derived from tissues such as human dermis and porcine small intestine submucosa, which must be rendered acellular to prevent disease transmission and decrease the risk of an immune response. The ideal decellularization technique removes cells and cellular remnants, but leaves the original collagen architecture intact. The tissue utilized in this study was the central tendon of the porcine diaphragm, which had not been previously investigated for soft tissue repair. Several treatments were investigated during this study including peracetic acid, TritonX-100, sodium dodecyl sulfate, and tri(n-butyl) phosphate (TnBP). Of the decellularization treatments investigated, only 1% TnBP was effective in removing cell nuclei while leaving the structure and composition of the tissue intact. Overall, the resulting acellular tissue scaffold retained the ECM composition, strength, resistance to enzymatic degradation, and biocompatibility of the original tissue, making 1% TnBP an acceptable decellularization treatment for porcine diaphragm tendon.

Malignant ascites of unknown origin

To determine the clinical characteristics of patients presenting with malignant ascites, as well as means of evaluating the outcome of patients with the disease, a retrospective review was conducted of all cases of malignant peritoneal effusions diagnosed from 1978 to 1987 at a University Hospital and a Veterans Administration Hospital. Of 65 patients with malignant ascites (40 women; 25 men), the primary site was known in 51 cases (80%). Common sites in women were the ovaries, endometrium, and cervix; in men, common sites were the colon, rectum, and stomach. For five women and nine men the primary site was unknown. Median survival from diagnosis was 7.5 days (mean, 43 days; range, 1–256 days). Chest radiograph and abdominal computed tomography (CT) scan did not disclose the occult primary. An occult primary was detected while the patient was alive in only two cases and at autopsy in two other patients. Due to the poor prognosis for this disease, we do not recommend an aggressive approach to malignant ascites of unknown origin, except perhaps in women, in whom ovarian cancer should be suspected.

Use of porcine dermal collagen as a prosthetic mesh in a contaminated field for ventral hernia repair: a case report

Chronic infection of a prosthetic mesh implant is a severe complication of ventral hernia repair, and mesh explantation is usually required in these cases. Biologic mesh implants have a possible role in ventral hernia repair in this setting. Here we present a case of chronic mesh infection following ventral hernia repair and the use of a biologic mesh to repair the existing defect following explantation of the infected mesh. Analysis of the explant material demonstrated possible oxidative degradation of the original polypropylene. A review of the literature follows.

A103 immunostaining in the diagnosis of adrenal cortical tumors: an immunohistochemical study of 316 cases.

CONTEXT The monoclonal antibody A103 recognizes an antigen on melanoma cells known as Melan-A or MART-1. Recent studies have shown that A103 also reacts with adrenal cortical cells and may be useful in the diagnosis of adrenal cortical tumors. However, only small numbers of some of the tumors in the differential diagnosis of adrenal cortical neoplasms have been studied. OBJECTIVE To study the specificity of A103 immunohistochemistry in a large number of tumors in the differential diagnosis of adrenal cortical neoplasms. DESIGN Formalin-fixed, paraffin-embedded tissue from 21 adrenal cortical tumors, 16 cases of metastatic carcinoma to the adrenal, 10 pheochromocytomas, and 269 extra-adrenal carcinomas was evaluated for A103 immunoreactivity using a commercially available antibody (Novocastra, Newcastle, UK). RESULTS Positive staining was seen in all of the adrenal cortical tumors but in none of the adrenal metastases or pheochromocytomas. In the 269 extra-adrenal carcinomas, A103 immunoreactivity was limited to a single ovarian serous carcinoma. CONCLUSION A103 immunostaining is useful in distinguishing adrenal cortical neoplasms from other carcinomas and pheochromocytoma.

Immunohistochemistry in ocular carcinomas.

Background:  The distinction between ocular sebaceous carcinoma, poorly differentiated ocular squamous cell carcinoma and ocular basal cell carcinoma can be challenging. An appropriate immunohistochemical panel may help to differentiate these lesions.

Characterization of heavyweight and lightweight polypropylene prosthetic mesh explants from a single patient

Although polypropylene has been used as a hernia repair material for nearly 50 years, very little science has been applied to studying the bodys effect on this material. It is possible that oxidation of mesh occurs as a result of the chemical structure of polypropylene and the physiological conditions to which it is subjected; this leads to embrittlement of the material, impaired abdominal movement, and chronic pain. It is also possible that lightweight polypropylene meshes undergo less oxidation due to a reduced inflammatory reaction. The objective of this study was to characterize explanted hernia meshes using techniques such as scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and compliance testing to determine whether the mesh density of polypropylene affects the oxidative degradation of the material. The hypothesis was that heavyweight polypropylene would incite a more intense inflammatory response than lightweight polypropylene and thus undergo greater oxidative degradation. Overall, the results support this theory.

Follicular carcinoma with clear cell change arising in lingual thyroid

A case of follicular carcinoma arising in the lingual thyroid of a 23-year-old woman is added to the 22 previous reports. The embryology and the clinical and pathologic differential diagnoses are discussed. Histologic criteria useful in diagnosing follicular malignancy in this area include local and vascular invasiveness, hypercellularity, mitotic activity, and necrosis. The use of the immunohistochemical marker thyroglobulin and electron microscopy are described for the first time and confirm a thyroid follicular cell origin.

Endoscopic colotomy closure for natural orifice transluminal endoscopic surgery using a T-fastener prototype in comparison to conventional laparoscopic suture closure

BACKGROUND Safe and efficient endoscopic closure of a colotomy is essential for transcolonic peritoneal access or endoscopic full-thickness resection of the colon, if open or laparoscopic surgery is to be avoided. OBJECTIVE To compare the feasibility and safety of colotomy closure with the newly developed Tissue Approximation System (TAS, Ethicon Endo-Surgery, Inc.) to conventional laparoscopic suture closure. DESIGN Prospective randomized survival animal study involving 16 pigs. SETTING University hospital. INTERVENTIONS Pigs were randomized for closure of a 2- to 3-cm full-thickness colotomy with the TAS or with a conventional laparoscopic running suture. MAIN OUTCOME MEASUREMENTS Success of colotomy closure, time of colotomy closure, postoperative infection, and complication rates. RESULTS Colotomies were successfully closed in all animals. Median closure time (range) was 39.5 minutes (25-95 min) in the TAS group and 23 minutes (16-40 min) in the laparoscopic group (P = .0134). There were no postoperative infections or complications. LIMITATIONS Closure with the TAS was performed under laparoscopic vision. There was no control group without closure of the colotomy site. CONCLUSIONS Colotomies are safely closed with the TAS with comparable results to laparoscopic closure. The TAS may serve as a useful tool to close full-thickness colon defects or colotomy sites made for transluminal endoscopic procedures.

Gastrotomy creation and closure for NOTES using a gastropexy technique (with video)

BACKGROUND Safe and efficient gastrotomy creation and closure is pivotal for natural orifice transluminal endoscopic surgery (NOTES). OBJECTIVE To test a method of transgastric access and closure with commercially available devices. DESIGN An animal survival study. SETTING University hospital. PATIENTS Fifteen pigs. INTERVENTIONS By using a surgical suture passer, under endoscopic guidance, 3 percutaneous stay sutures were placed, in a triangular fashion, through the gastric wall. A gastrotomy was created with a dilation balloon, which was introduced over a guidewire through the gastric wall in the center of the 3 sutures. After performing a NOTES procedure, the gastrotomy was closed by tying the sutures. Necropsies were performed after 2 to 4 weeks. MAIN OUTCOME MEASUREMENTS Success and time of gastrotomy creation and closure, and intraoperative and postoperative complications. RESULTS Gastrotomies were successfully created and closed in all the animals. The median time to create a gastrotomy was 19 minutes (range 11-85 minutes), and the median closure time was 1 minute (range 1-45 minutes). One pig died on postoperative day 1 because of peritonitis caused by a leaking gastrotomy site that extended beyond the stay sutures. There were no other gastrotomy-related complications. All gastrotomies were well healed at the necropsy. LIMITATION No control group. CONCLUSIONS We evaluated a simple method by using the principles of the PEG technique combined with a gastropexy, which is familiar to the majority of endoscopists. Strict attention to the gastrotomy site is needed, because one leak was from the gastrotomy site that extended beyond the stay sutures.