Mark A. Weiss

The World Health Organization/International Society of Urological Pathology consensus classification of urothelial (transitional cell) neoplasms of the urinary bladder

In October 1997, Dr. F.K. Mostofi assembled a group of individuals interested in bladder neoplasia at a meeting in Washington DC. The participants included urologic pathologists, urologists, urologic oncologists, and basic scientists with an interest in bladder neoplasia. The purpose of this meeting was to discuss bladder terminology and make recommendations to the World Health Organization (WHO) Committee on urothelial tumors. Following this meeting, a group of the urologic pathologists who attended the Washington meeting decided to broaden the representation of the group and arranged a meeting primarily of the members of the International Society of Urologic Pathologists (ISUP) at the 1998 United States and Canadian Academy of Pathology Meeting held in Boston. Massachusetts. At this meeting. issues regarding terminology of bladder lesions, primarily neoplastic and putative preneoplastic lesions, were discussed, resulting in a consensus statement. The WHO/ ISUP consensus classification arises from this consensus conference committees recommendations to the WHO planning committee and their agreement with virtually all of the proposals presented herein. 29 The effort involved in reaching such a consensus was often considerable. Many of those involved in this process have compromised to arrive at a consensus. The aim was to develop a universally acceptable classification system for bladder neoplasia that could be used effectively by pathologists, urologists, and oncologists.

Spindle-cell carcinoma of the upper aerodigestive tract mucosa. An immunohistologic and ultrastructural study of 18 biphasic tumors and comparison with seven monophasic spindle-cell tumors.

The histogenetic origin of the spindle-cell component of spindle-cell carcinoma of the head and neck mucosa remains controversial. The spindle cells have been considered a variant growth pattern of squamous-cell carcinoma, a non-neoplastic mesenchymal reaction, and a malignant admixture of epithelial and mesenchymal neoplasm. To evaluate the spindle-cell component, we studied 25 tumors (18 biphasic and seven monophasic) by utilizing the following: (a) an avidin-biotin complex immunoperoxidase technique with a variety of antikeratin antibodies (AE1, AE3, CAM 5.2, 35BH11, and polyclonal Dako) and a monoclonal antivimentin antibody, and (b) an avidin-biotin alkaline phosphatase double-labeling technique to detect coexpression of keratin and vimentin. The immunohistologic staining pattern was compared with electron-microscopic studies. Eight of 18 biphasic neoplasms contained immunoreactive keratin in the spindle-cell component that was distributed focally in a minority of cells in 3 tumors and diffusely throughout five of the neoplasms. Four of seven ulcerated monophasic spindle-cell tumors devoid of histologic squamous- cell carcinoma also were keratin positive, confirming epithelial differentiation. The majority of the spindle cells in all the tumors contained vimentin intermediate filaments. In three immunoperoxidase keratin positive biphasic tumors examined with alkaline phosphatase double labeling, occasional spindle cells were found that coexpressed keratin and vimentin and were interspersed with cells expressing either intermediate filament. Electron microscopy was performed on the spindle-cell component of 13 tumors, nine biphasic and four monophasic. Of the biphasic tumors, four were immunoperoxidase keratin positive; three of these showed epithelial differentiation by electron microscopy. Five biphasic tumors were keratin negative, and three tumors had epithelial differentiation by electron microscopy. Four monophasic spindle-cell tumors were immunoperoxidase keratin positive, and one of these had epithelial features by electron microscopy. Two monophasic tumors were keratin negative and without ultrastructural evidence of epithelial features. By using a combination of immunohistochemical and electron-microscopic observations, we identified evidence for epithelial differentiation in the spindled cells in 11 of 18 biphasic tumors and four of seven monophasic spindle-cell tumors.

Small cell undifferentiated carcinoma of the urinary bladder. A light-microscopic, immunocytochemical, and ultrastructural study of 12 cases.

The clinicopathologic, immunocytochemical, and ultrastructural features of 12 small cell undifferentiated carcinomas (SCUCs) of the urinary bladder are herein reported. The patients ranged in age from 50 to 82 years (median, 76 years). Ten patients were male and two were female. Gross hematuria was the most frequent complaint (67%). Five patients died of disease (median survival, 4 months), three patients are still living with unresectable disease after 6, 10, and 12 months, and four patients were only recently diagnosed. Grossly, most of the tumors were large polypoid masses. On light-microscopic examination, they resembled the intermediate and oat cell variants of pulmonary SCUC. Eight SCUC were associated with other forms of in situ or invasive carcinoma, including transitional cell carcinoma (seven cases), adenocarcinoma (three cases), squamous cell carcinoma (three cases), spindle cell carcinoma (one case), and atypical carcinoid tumor (one case). Immunocytochemically, 11 of the 12 tumors expressed one or more epithelial cell markers (epithelial membrane antigen, human milk fat globule protein-2, cytokeratin). Eleven of the 12 SCUCs were also positive for one or more neuroendocrine markers (neuron specific enolase, chromogranin, Leu-7, vasoactive intestinal polypeptide, serotonin). Electron microscopy performed on seven tumors demonstrated dense-core granules (150-250 nm) in all cases, with tonofilaments in four cases, dendrite-like processes in two cases, and intercellular lumina in one case. The clinicopathologic features of 18 previously reported SCUC of the urinary bladder are also reviewed. SCUC arising in this location is an aggressive neoplasm that often demonstrates multidirectional differentiation, including the frequent but not invariable expression of neuroendocrine features.

Nephrotic Syndrome, Progressive Irreversible Renal Failure, and Glomerular “Collapse”: A New Clinicopathologic Entity?

Six patients are reported with nephrotic syndrome and relatively rapid progression to irreversible renal failure. The renal histologic findings are unusual. The most striking changes are collapse of glomerular capillary loops, such as might occur with glomerular hypoperfusion; significant tubulointerstitial damage is also seen. These patients appear to have a clinicopathologic entity hitherto unreported. Its differentiation from other causes of progressive glomerular damage, and particularly from focal and segmental glomerulosclerosis, is discussed.

Comparison of the AngioJet Rheolytic Catheter to Surgical Thrombectomy for the Treatment of Thrombosed Hemodialysis Grafts

PURPOSE To compare the clinical effectiveness of the AngioJet F105 rheolytic catheter to that of surgical thrombectomy for the treatment of thrombosed hemodialysis grafts. MATERIALS AND METHODS This was a multicenter, prospective, randomized trial comparing technical success, primary patency, and complication rates. A total of 153 patients were enrolled: 82 patients in the AngioJet group and 71 patients in the surgical thrombectomy group. Patient follow-up was performed 24-48 hours, 1 month, and 6 months after the procedures. RESULTS Technical success, as defined by the patients ability to undergo hemodialysis treatment, was 73.2% for the AngioJet group and 78.8% for the surgical thrombectomy group (P = .41). The primary patency rates of the AngioJet group were 32%, 21%, and 15% at 1, 2, and 3 months, respectively. The primary patency rates for the surgical group were 41%, 32%, and 26% at 1, 2, and 3 months, respectively. This difference approached statistical significance (P = .053). The groups had similar complication rates-14.6% in the AngioJet group and 14.1% in the surgery group-although the surgery group had more major complications (11.3%). In the AngioJet group, there was a transient increase in plasma-free hemoglobin, which normalized within 24-48 hours. CONCLUSIONS The AngioJet F105 catheter provides similar clinical results when compared to surgical thrombectomy for the treatment of thrombosed hemodialysis grafts. The difference in patency rates between these two techniques approached statistical significance. In addition, results of both thrombectomy methods were inferior to those suggested by the Dialysis Outcomes Quality Initiative guidelines.

Pentostatin and Cyclophosphamide: An Effective New Regimen in Previously Treated Patients With Chronic Lymphocytic Leukemia

PURPOSE Purine analogs and alkylators are important agents in the treatment of chronic lymphocytic leukemia (CLL). Previously, combinations of fludarabine and chlorambucil were abandoned because of increased toxicity from overlapping myelosuppression and immunosuppression. Of the purine analogs active in CLL, pentostatin may be least myelosuppressive. We hypothesized that combining pentostatin with cyclophosphamide would have less myelotoxicity than combinations using other purine analogs. PATIENTS AND METHODS We studied 23 patients with previously treated CLL. All patients received pentostatin 4 mg/m(2). Seventeen patients received cyclophosphamide 600 mg/m(2), and six patients received cyclophosphamide 900 mg/m(2). Both drugs were administered on day 1 of each cycle, and cycles were repeated every 3 weeks for six treatments. Filgrastim, sulfamethoxazole/trimethoprim, and acyclovir were administered prophylactically. The median number of prior treatment regimens was three (range, one to five) with 13 patients (57%) refractory to prior fludarabine therapy. RESULTS The cyclophosphamide 900 mg/m(2) dose level was associated with moderate to severe nausea, and we chose cyclophosphamide 600 mg/m(2) as the dose for further study. There were 17 responses (74%; 95% confidence interval, 63% to 85%), including four complete responses. The response rate was 77% in fludarabine-refractory patients. Myelosuppression was acceptable with grade 3/4 neutropenia and thrombocytopenia, seen in 35% and 30% of patients, respectively. The relative sparing of thrombopoiesis can be seen in that only one patient (5%) with an initial platelet count of more than 20,000 required platelet transfusions while receiving therapy. CONCLUSION Pentostatin 4 mg/m(2) with cyclophosphamide 600 mg/m(2) is safe and effective in previously treated patients with CLL. On the basis of these results, we are currently studying pentostatin, cyclophosphamide, and rituximab (PCR) therapy in patients with CLL.

PROTEINURIA FOLLOWING TRANSPLANTATION: Correlation With Histopathology And Outcome

A review of 693 renal transplant recipients revealed 77 (11%) in whom persistent, heavy proteinuria (>2 g/ 24 hr) developed. Renal histology was available in all 77 patients. Twenty-one patients had received kidneys from living-related donors, the remaining 56 from cadaveric donors. The cause of proteinuria in these 77 patients was as follows: transplant glomerulopathy (30), allograft glomerulonephritis (22), chronic rejection (21), renal vein thrombosis (2), diabetic glomerulosclerosis (1), and hypertensive nephrosclerosis (1). Of the 22 patients who developed glomerulonephritis in the transplanted kidney, 6 had recurrent disease (3—membranous glomerulopathy, 2—focal sclerosis and hyali- nosis, 1—membranoproliferative glomerulonephritis); 6 developed de novo glomerulonephritis; and in 10 the type of glomerulonephritis could not be classified as recurrent or as de novo because of lack of characterization of the original kidney disease. Renal vein thrombosis occurred in association with other lesions in an additional 5 cases (3—chronic rejection; 2—membranous glomerulopathy). In follow-up only 23.4% (18 of 77) of the patients maintained prolonged graft function; the majority of grafts being lost within one year of the development of persistent, heavy proteinuria. Of the 18

Inflammatory myofibroblastic tumors of the kidney: a clinicopathologic and immunohistochemical study of 12 cases.

&NA; Inflammatory myofibroblastic tumor is a rare entity composed of spindle cells admixed with variable amounts of extracellular collagen, lymphocytes, and plasma cells. In the genitourinary tract, inflammatory myofibroblastic tumor most commonly occurs in the bladder. Isolated case studies of inflammatory myofibroblastic tumor of the kidney, renal pelvis, and ureter have been previously reported. Our series includes 12 cases of inflammatory myofibroblastic tumor occurring in the renal pelvis (six cases), renal parenchyma (four cases), and immediate perirenal soft tissue (two cases). Clinical presentation included flank pain (two patients), painless gross hematuria (one patient), and ureteropelvic junction stenosis with hydronephrosis (one patient). The remaining eight patients were asymptomatic. All patients underwent nephrectomy. The tumors were characterized by firm white tissue or had a myxoid “gelatinous” appearance. Three histologic patterns were identified in the tumors, including a myxoid vascular pattern, a compact spindle cell pattern, and a hypocellular fibrous pattern. Immunohistochemical and electron microscopic studies supported a myofibroblastic proliferation. All cases were negative for anaplastic lymphoma kinase. Follow‐up was available in eight cases and ranged from 1 to 17 years with no evidence of recurrence. Based on this series, renal inflammatory myofibroblastic tumor is a proliferative lesion of myofibroblasts of uncertain pathogenesis with no identified potential for recurrence or metastases.

Cytarabine with high-dose mitoxantrone induces rapid complete remissions in adult acute lymphoblastic leukemia without the use of vincristine or prednisone.

PURPOSE To evaluate the efficacy and safety of a new induction regimen for adult acute lymphoblastic leukemia (ALL) that does not contain vincristine or corticosteroids. PATIENTS AND METHODS Thirty-seven adult patients with newly diagnosed ALL and lymphoblastic lymphoma were treated with a dose-intense induction regimen. This regimen was designed to increase the fraction of patients achieving an early complete remission (CR) in an attempt to increase long-term disease-free survival. The induction regimen was cytarabine (Ara-C) 3 g/m2/d for 5 days and mitoxantrone 80 mg/m2 as a single dose on day 3. Granulocyte colony-stimulating factor (G-CSF) 200 micrograms/ m2/d beginning on day 7 was used to promote early myeloid recovery. RESULTS There were 31 CRs (84%). Median time to CR was 34 days, median hospital stay was 28 days, and the median number of days with a neutrophil count less than 500/microL was 18. There were three patients with resistant disease who experienced treatment failure and three early deaths from sepsis. Four patients with Philadelphia chromosome-positive (Ph+) ALL achieved hematologic and cytogenetic CRs. CONCLUSION This dose-intense induction regimen produced a high incidence of CRs with acceptable toxicity without the use of vincristine or corticosteroids. Comparisons with our prior vincristine/prednisone-based induction regimen (the L-20 protocol) suggest that patients treated on the current study were more likely to achieve a CR and that they achieved this remission earlier than patients treated with a traditional four-drug (vincristine, prednisone, doxorubicin, and cyclophosphamide) induction regimen.

Squamous papillary neoplasia of the adult upper aerodigestive tract

Selected papillary squamous tumors of the upper aerodigestive tract (UADT) mucosa in adult patients do not have well-defined histologic criteria and the clinical behavior is poorly understood. To better characterize this spectrum of neoplasms, UADT papillary neoplasms were evaluated by routine histology, determination of cellular DNA content using Feulgen-stained tissue sections, and the typing of human papillomavirus (HPV) by in situ hybridization. Solitary papillomas were studied in two patients; there was no recurrence in either case, both had normal DNA content, and one was typed as HPV-6 while the other was typed as HPV-11. Seven adult patients with recurrent papillomatosis and at least one biopsy with dysplasia/atypia were identified (mean age at diagnosis, 13.3 years; mean age at last contact, 42.7 years). Six of seven patients had abnormal DNA cellular content in foci of epithelial atypia. In all biopsies evaluated, the papillomas of the seven patients were consistently typed as either HPV-6 or HPV-11. Six patients with malignant papillary neoplasms also had abnormal DNA cellular content, but none revealed evidence of HPV type 6, 11, 16, or 18 by in situ hybridization of tissue sections. In many of the recurrent papillomas, the degree of epithelial atypia encountered was pronounced and was commonly misdiagnosed as carcinoma in situ or papillary carcinoma. The aneuploid DNA content of these foci of atypia reflected the abnormal cellular appearance and partially explained the overdiagnosis of malignancy. However, none of the seven patients were treated for malignant disease and none progressed to invasive carcinoma, with an average follow-up period of almost 30 years. We conclude that histologic and cytologic atypia in HPV-containing papillomatosis may be appreciable. The aneuploid DNA content may represent premalignant conditions and the patient may be at an increased risk for the subsequent development of squamous cancer. However, none of the seven patients with recurrent papillomatosis developed any evidence of malignancy. In addition, none of the patients with papillary carcinomas had previous recurrent papillomatosis.