Role of pulsatile perfusion with tissue plasminogen activator in deceased donor kidneys with extensive glomerular thrombosis.

BACKGROUND: Pulsatile perfusion (PP) improves delayed graft function, whereas tissue plasminogen activator (tPA) lyses thrombi. We studied the role of PP with tPA containing perfusate in deceased donor kidneys (DDK) with 50% thrombosed glomeruli. METHODS: Fourteen DDK with extensive glomerular thrombi on biopsies were preserved using PP with histidine-tryptophan-ketoglutarate solution containing tPA. Wedge biopsies were repeated after PP. RESULTS: Causes of donor death included closed head trauma in 8, anoxia in 2, and stroke in 4. Donors who averaged 33.3 years old displayed a final 24-hour urine volume of 1933 mL, a terminal serum creatinine level of 1.8 mg/dL, a blood urea nitrogen of 20 mg/dL, and a platelet count of 128,000/microL. The initial flow of 47 mL improved to 111 mL/min after 16.17 hours of perfusion. Resistive indices (RI) decreased from 0.69 to 0.26 at 4.2 degrees C. Biopsy specimens after PP showed a reduction in glomerular thrombi from 50% to 23%. Recipients averaged 54.9 years old. Cold ischemia time averaged 35.5 hours. One patient displayed primary allograft nonfunction, 3 required transient dialysis, and 10 showed prompt allograft function. Recipient follow-up averaged 12 months, with serum creatinine levels of 4.3 mg/dL at 1 week, 2.0 mg/dL at 1 month, and 1.6 mg/dL at last follow-up. CONCLUSIONS: Renal allografts with extensive glomerular thrombosis improved their biopsy appearance following PP with tPA. Improvement in PP parameters allowed successful transplantation of such kidneys that otherwise would have been discarded. PP with tPA appears to be beneficial for kidneys with extensive glomerular thrombosis.

The "fatty pancreas allograft": anatomopathologic findings and clinical experience.

Thirty-three hematoxylin and eosin-stained sections from 7 turned down pancreata from donors with body mass index (BMI) of 33.3 (range, 28-42) were examined. There was more fat infiltration between the superficial pancreatic lobules, interspersed with superficial islands of pancreatic tissue with its vessels and ductules. Thicker fatty interlobular septa were observed with numerous intralobular fat vacuoles. One organ had widespread autolysis. No microthrombi were noted. One pancreas from a 24-year-old donor with BMI of 30 was transplanted successfully. The "fatty pancreas" can be defatted and used for transplantation.

Microtubule-associated protein-2: a new sensitive and specific marker for pulmonary carcinoid tumor and small cell carcinoma.

Microtubule-associated proteins (MAPs) are a major component of cytoskeleton family proteins associated with microtubule assembly. MAP-2 has been shown to be specifically expressed in neuronally differentiated cells. Pulmonary neuroendocrine carcinomas such as carcinoid tumors and small cell carcinomas are derived from neuroendocrine cells. We hypothesize that neuroendocrine cells may also express MAP-2, and therefore, MAP-2 may be used as a marker for pulmonary carcinomas of neuroendocrine differentiation. To investigate the utility of using MAP-2 expression to separate pulmonary neuroendocrine from non-neuroendocrine tumors, we examined the expression of MAP-2 immunohistochemically in 100 cases of pulmonary carcinomas. The immunoperoxidase method with antigen retrieval was used to characterize the expression of MAP-2, chromogranin, synaptophysin, and neuron-specific enolase in 25 small cell carcinomas, 25 carcinoid tumors, 25 adenocarcinomas, and 25 squamous cell carcinomas. All tumors were lung primaries. All 25 cases of carcinoid tumors (100%) as well as 23 of 25 cases (92%) of small cell carcinomas were positive for MAP-2. Four of 25 cases (16%) of adenocarcinomas were positive for MAP-2 and synaptophysin. Among the 25 squamous carcinomas, 4 cases (16%) were positive for MAP-2, 2 cases (8%) were positive for synaptophysin, 11 cases (44%) were positive for neuron-specific enolase, and none was positive for chromogranin. In conclusion, MAP-2 is a new sensitive and specific marker for the pulmonary tumors of neuroendocrine differentiation. We recommend that MAP-2 be added to immunohistochemical panels to separate non-neuroendocrine from neuroendocrine lung tumors.

Fine-needle aspiration cytology of low-grade fibromyxoid sarcoma of the renal capsule (capsuloma).

We report on the fine-needle aspiration (FNA) findings of a low-grade fibromyxoid sarcoma arising from the renal capsule in a 70-yr-old male. Cytologic examination revealed a spindle-cell and myxoid lesion characterized by microtissue fragments of delicate spindle-shaped cells and thin-walled capillary-type channels enmeshed in metachromatically staining myxoid material, best appreciated in Diff-Quik-stained smears. The spindle cells had slightly elongated, bland, oval to tapered nuclei. Based on the FNA diagnosis, the renal mass was resected, which revealed a hypocellular to moderately cellular, spindle-shaped neoplasm showing alternating hypercellular fibrous foci with hypocellular myxoid areas arranged in a swirling growth pattern, characteristic of low-grade fibromyxoid sarcoma. We believe that this is the first report of a low-grade fibromyxoid sarcoma arising in the renal capsule (capsuloma), as well as the first capsuloma diagnosed by FNA biopsy. Differential diagnoses of other sarcomas arising from the kidney and nearby retroperitoneal region are discussed, as well as other entities that might enter into the differential diagnosis of this low-grade sarcoma.

Characterization of signal properties in atherosclerotic plaque components by intravascular MRI.

Magnetic resonance imaging (MRI) is capable of distinguishing between atherosclerotic plaque components solely on the basis of biochemical differences. However, to date, the majority of plaque characterization has been performed by using high-field strength units or special coils, which are not clinically applicable. Thus, the purpose of the present study was to evaluate MRI properties in histologically verified plaque components in excised human carotid endarterectomy specimens with the use of a 5F catheter-based imaging coil, standard acquisition software, and a clinical scanner operating at 0.5 T. Human carotid endarterectomy specimens from 17 patients were imaged at 37 degrees C by use of an opposed solenoid intravascular radiofrequency coil integrated into a 5F double-lumen catheter interfaced to a 0.5-T General Electric interventional scanner. Cross-sectional intravascular MRI (156x250 microm in-plane resolution) that used different imaging parameters permitted the calculation of absolute T1and T2, the magnetization transfer contrast ratio, the magnitude of regional signal loss associated with an inversion recovery sequence (inversion ratio), and regional signal loss in gradient echo (gradient echo-to-spin echo ratio) in plaque components. Histological staining included hematoxylin and eosin, Masson's trichrome, Kossa, oil red O, and Gomori's iron stain. X-ray micrographs were also used to identify regions of calcium. Seven plaque components were evaluated: fibrous cap, smooth muscle cells, organizing thrombus, fresh thrombus, lipid, edema, and calcium. The magnetization transfer contrast ratio was significantly less in the fibrous cap (0.62+/-13) than in all other components (P<0.05) The inversion ratio was greater in lipid (0.91+/-0.09) than all other components (P<0.05). Calcium was best distinguished by using the gradient echo-to-spin echo ratio, which was lower in calcium (0.36+/-0.2) than in all plaque components, except for the organizing thrombus (P<0.04). Absolute T1 (range 300+/-140 ms for lipid to 630+/-321 ms for calcium) and T2 (range 40+/-12 ms for fresh thrombus to 59+/-21 ms for smooth muscle cells) were not significantly different between groups. In vitro intravascular MRI with catheter-based coils and standard software permits sufficient spatial resolution to visualize major plaque components. Pulse sequences that take advantage of differences in biochemical structure of individual plaque components show quantitative differences in signal properties between fibrous cap, lipid, and calcium. Therefore, catheter-based imaging coils may have the potential to identify and characterize those intraplaque components associated with plaque stability by use of existing whole-body scanners.

Pleural fluid cytology of Hodgkin's disease: cytomorphologic features and the value of immunohistochemical studies.

Two cases in which Hodgkin's disease (HD) was cytologically diagnosed in pleural effusions are presented. The presence of Reed-Sternberg (R-S) cells was confirmed by positive staining for both CD15 and CD30, and negative staining for leukocyte common antigen. In addition, the differential diagnosis of HD in effusion cytology is presented, including look-alikes of R-S cells that can potentially lead to an incorrect diagnosis. To the best of our knowledge, we believe this is only the second cytologic report of HD diagnosed in a pleural effusion using immunohistochemistry to confirm the diagnosis.

Immunohistochemical study of insulin-like growth factor II (IGF-II) and insulin-like growth factor binding protein-2 (IGFBP-2) in choroid plexus papilloma.

Insulin-like growth factor-II (IGF-II), a mitogen for various kinds of cells, has been shown to be secreted from the choroid plexus in animals. Insulin-like growth factor binding protein-2 (IGFBP-2), one of the six carrier proteins for IGFs, is also thought to be released from the choroid plexus, bind to IGF-II in the cerebrospinal fluid (CSF) and modulate the action of this growth factor. Little is known about the expression and localization of these substances in human choroid plexus and choroid plexus papillomas. The present immunohistochemical study demonstrated all six choroid plexus papillomas were positive for IGF-II, whereas normal choroid plexuses were negative for IGF-II. On the other hand, IGFBP-2 was positive in the endothelium and vascular media in the normal choroid plexus, while it was weakly positive in four and negative in two out of six choroid plexus papillomas. These results suggest that the alterations in the IGF-II/IGFBP-2 axis might be involved in the tumorigenesis of choroid plexus papilloma.

Fine-needle aspiration cytology of a mediastinal seminoma associated with multilocular thymic cyst.

Multiloculated thymic cysts are uncommon lesions that can be either acquired or associated with malignancies. This report describes the fine-needle aspiration (FNA) cytology of a mediastinal seminoma with prominent cystic change, confirmed by surgical pathology examination and ancillary studies performed on both the cytology and tissue specimens. The FNA cytology revealed clusters of malignant oval-to-polygonal-shaped cells with large oval nuclei possessing prominent nucleoli set in a pale-to-eosinophilic cytoplasm. These cells were surrounded by a dense lymphoid infiltrate along with a few noncaseating granulomas. The large malignant seminoma cells stained positive for placental alkaline phosphatase (PLAP) and negative for both low molecular and broad-spectrum cytokeratin. The differential diagnosis of malignancies associated with thymic cysts is presented. To the best of our knowledge, this is the first report of aspiration cytology of a mediastinal seminoma associated with a multilocular cyst.

Solitary fibrous tumor of the orbit.

Solitary fibrous tumor (SFT) of the orbit is a very rare lesion that may be misdiagnosed as fibrous histiocytoma, hemangiopericytoma, or other orbital tumors. We present a 62-year-old man who presented with painless proptosis, 20 years following left eye enucleation for a presumed neurofibroma. On T2-weighted magnetic resonance imaging (MRI), a hypointense tumor almost filled his entire left orbit. There was no intracranial extension. The specimen obtained at orbital exenteration was consistent with the histologic, immunohistochemical, and electron microscopic findings of SFT. The tumor was positive for vimentin and CD34 staining but negative for S-100 protein and epithelial membrane antigen. Only nine other cases of SFT of the orbit have been documented in the literature. Recognition of SFT of the orbit as a distinct pathologic entity and further follow-up of published cases are needed to determine the prognosis of this rare lesion.