Nephrolithiasis associated with autosomal dominant polycystic kidney disease: contemporary urological management

PURPOSE

We evaluate the role of contemporary urological intervention in patients with nephrolithiasis associated with autosomal dominant polycystic kidney disease.

MATERIALS AND METHODS

Intervention for upper tract stones associated with autosomal dominant polycystic kidney disease was performed in 5 women and 2 men 29 to 65 years old (mean age 47). Indications for intervention consisted of flank pain in 6 patients and/or hematuria in 2. A total of 12 procedures (mean 1.7 per patient) were performed, including shock wave lithotripsy in 6 patients, percutaneous nephrolithotomy in 2, retrograde endoscopy or manipulation in 3 and extended pyelonephrolithotomy in 1.

RESULTS

All patients were rendered stone-free or had only residual "dust." Hospital stay for 5 patients was 1 night or less and there were no complications. Renal function for each patient was stable or improved as measured by serum creatinine.

CONCLUSIONS

Most patients with autosomal dominant polycystic kidney disease who require intervention for nephrolithiasis can be safely and effectively treated with essentially any or all contemporary, minimally invasive techniques. The choice of intervention can be based primarily on size and location of the upper tract stones rather than the associated presence of polycystic kidneys.

Contemporary management of cystinuria

Cystinuria is an autosomal recessive disorder characterized by a defect in intestinal and renal tubular transport of dibasic amino acids which results in excessive urinary excretion of cystine. Because of the relative insolubility of cystine in urine, patients with this condition are prone to recurrent stone formation. Medical therapy aims both to decrease the urinary concentration of cystine and to increase its solubility. Standard prevention and treatment regimens include hydration, moderate salt and protein restriction, oral alkalinization, and thiol derivatives. Despite aggressive medical management, however, cystinuric patients are likely to suffer frequent recurrent episodes of stones necessitating urologic intervention. Fortunately, the application of safe and efficacious minimally invasive modalities, including advancements in shockwave lithotripsy, ureteroscopic lithotripsy, and percutaneous nephrolithotomy, have obviated open operative intervention in nearly all cases.

A CT sign of chronic pulmonary arterial hypertension: the ratio of main pulmonary artery to aortic diameter

The aim of this study was to determine whether the ratio of the diameters of the main pulmonary artery and of the ascending aorta (rPA), as assessed on computed tomography (CT), is predictive of pulmonary arterial hypertension (PAH). We undertook a retrospective review of 50 patients with a wide range of pulmonary and cardiovascular diseases, who had undergone both chest CT and pulmonary arterial pressure measurements at right heart catheterization. Two independent observers made measurements of the diameter of the main pulmonary artery and of the ascending aorta on a single defined CT section. Body surface area (BSA, n = 48), pulmonary arteriolar resistance (n = 39), total lung capacity (n = 40), and aortic pressures (n = 50) were also recorded. rPA and pulmonary arterial diameter (dPA) were positively related to mean pulmonary artery pressure (Rs = 0.74, p < 0.0005 for both analyses). For patients younger than 50 years of age, mean pulmonary artery pressure correlated more strongly with rPA than dPA (Rs = 0.77, p < 0.00005, compared with Rs = 0.59, p < 0.005); and vice versa for patients older than 50 years of age (Rs = 0.63, p < 0.005, compared with Rs = 0.75, p < 0.00005). Using a mean pulmonary artery pressure greater than 20 mm Hg as indicative of PAH and a value of rPA > 1, the sensitivity, specificity, and positive and negative predictive values for determining PAH were 70% (26/37), 92% (12/13), 96% (26/27), and 52% (12/23), respectively. On multivariate analysis, rPA was positively related to mean pulmonary artery pressure (p < 0.0005), and negatively related to age (p < 0.0005), but was not related to BSA. By contrast, dPA showed some dependency on BSA (p < 0.0005), as well as on mean pulmonary arterial pressure. In patients younger than 50 years of age, we have found a strong correlation between rPA and mean pulmonary artery pressure in a heterogeneous study population, and this relationship is independent of BSA and sex. The presence of the sign "rPA > 1" is simple in practical CT reading to determine; if this is identified, there is a very high probability of pulmonary arterial hypertension, and clinicians should be alerted to this possibility.

Visual quantitation and observer variation of signs of small airways disease at inspiratory and expiratory CT

Areas of decreased pulmonary attenuation representing small airways disease can be identified on computed tomography (CT). The objective was to quantify differences between inspiratory and expiratory CT for the detection of signs of small airways disease by four observers. Observer variation and the superiority of a fine versus a coarse grading system were also evaluated. Inspiratory and expiratory CT scans of 106 patients with conditions characterized by small airways disease and 19 healthy individuals were assessed by four observers. The extent of decreased attenuation was scored on a fine scale to the nearest 5% and also semiquantitatively on a coarser 5-point scale. Decreased attenuation was more extensive on expiratory CT (median. 6.7%; 0-76.7%) than on inspiratory CT (median, 3.8%; 0-81.7%). The fine scoring system had unacceptable interobserver variation (coefficient of variation, 80% for inspiratory CT, 70% for expiratory CT). The semiquantitative system had acceptable interobserver agreement (inspiratory CT k(w) = 0.64; expiratory CT, k(w) = 0.69) and good intra-observer agreement (inspiratory CT, k(w) = 0.80; expiratory CT, k(w) = 0.64). The major CT sign of small airways disease is more confidently quantified on expiratory CT. A fine scoring system is associated with unacceptable observer variation, and a coarse semiquantitative system is more suitable for quantitative studies of small airways disease.

Retroperitoneoscopic surgery is not associated with increased carbon dioxide absorption

PURPOSE

Previous studies have suggested that retroperitoneal laparoscopy is associated with greater carbon dioxide absorption and related postoperative morbidity, such as subcutaneous emphysema and pneumothorax. We prospectively compared the effects of carbon dioxide absorption during transperitoneal and retroperitoneal laparoscopic renal and adrenal surgery at our institution.

MATERIALS AND METHODS

Data were collected prospectively on 51 patients who underwent laparoscopic renal (26) or adrenal (25) surgery via the transperitoneal (18) or retroperitoneal (33) approach from September 1997 to February 1998.

RESULTS

There was no significant difference in carbon dioxide elimination in patients who underwent transperitoneal laparoscopy compared to retroperitoneoscopy at any interval. Subcutaneous emphysema occurred in 12.5% of the transperitoneal and 45% of the retroperitoneal group (p = 0.09). Patients with subcutaneous emphysema had greater carbon dioxide elimination during the first 2.5 hours of insufflation compared to those without subcutaneous emphysema and, thereafter, carbon dioxide elimination decreased to baseline.

CONCLUSIONS

In contrast to previous reports our prospective nonrandomized study suggests that retroperitoneoscopy is not associated with greater carbon dioxide absorption compared to transperitoneal laparoscopy. Patients with subcutaneous emphysema exhibited only transient increases in carbon dioxide absorption above control levels.

Conservative management of an ileal neobladder-enteric fistula

We present a case of an early ileal neobladder-enteric fistula after radical cystectomy with Studer pouch creation for muscle-invasive transitional cell carcinoma of the bladder. This patient was treated conservatively on an outpatient basis with prolonged catheter drainage, a low-residue diet, and oral antibiotics, with complete resolution by 8 weeks. The rationale for this approach in selected patients is discussed.

Malignant pleural mesothelioma: the spectrum of manifestations on CT in 70 cases

AIM

The aim of this pictorial review is to illustrate the spectrum of manifestations on computed tomography (CT) of malignant pleural mesothelioma. Malignant pleural mesothelioma is the most common primary neoplasm of the pleura, but nevertheless is a rare tumour. It has a strong association with previous occupational exposure to asbestos and has a bleak prognosis.

MATERIALS AND METHODS

The pre-treatment CT findings of 70 patients at our institution, and the subsequent findings of the 35 patients who had follow-up CT, have been reviewed by three observers by consensus. 16 patients had surgical resections.

RESULTS

The most common pre-treatment findings were pleural thickening (94%) and pleural effusions (76%). Both contraction (27%) and enlargement (10%) of the ipsilateral hemithorax were identified. Extension of disease to the chest wall, mediastinum, thoracic lymph nodes, and below the diaphragm were identified. Concurrent bilateral pleural calcification and plaques indicative of previous asbestos exposure were identified in 16% of patients. CT failed to identify chest wall and mediastinal invasion in a number of patients who underwent surgical resections.

CONCLUSION

CT plays an important role in the diagnosis, assessment, and evaluation of treatment response of this tumour, although it has some limitations in specific areas in evaluating patients for surgical resection.

Metastases to the pancreas from renal cell carcinoma: findings on three-phase contrast-enhanced helical CT

OBJECTIVE

Our goal was to define the lesion enhancement characteristics of renal cell carcinoma metastases to the pancreas using three-phase helical CT.

MATERIALS AND METHODS

Thin-section three-phase contrast-enhanced CT scans of nine patients with renal cell carcinoma metastases to the pancreas were evaluated. The helical CT protocol included 3-mm collimation and a 2:1 pitch. Scans through the pancreas were obtained in three series beginning 25, 60, and 120 sec after the start of administration of i.v. contrast material delivered at 3 ml/sec. The Hounsfield densities of the pancreatic lesions and normal pancreatic parenchyma during each of the enhancement phases were recorded and compared.

RESULTS

The enhancement patterns of the metastatic deposits and the normal pancreas differed. Thirty-four lesions ranging in size from 6 to 110 mm were identified. All metastases showed rapid enhancement during the early (arterial and portal) phases, resulting in differential attenuations (compared with normal pancreatic parenchyma) of approximately 50-100 H. The differential attenuations were approximately 5-45 H on delayed-phase scans, resulting in poorer conspicuity of the lesions. Multifocal metastases were clearly identified on the early-phase scans in seven patients.

CONCLUSION

Renal cell carcinoma metastases to the pancreas enhance most conspicuously during the early phases of helical CT. Such metastases may fail to be appreciated in the delayed phase. In patients with suspected renal cell carcinoma metastases to the pancreas, early-phase scanning after i.v. contrast administration should be performed.

Peripheral T and putative natural killer cell lymphomas commonly coexpress CD95 and CD95 ligand

The CD95 (Fas)/CD95 ligand (CD95L) system is an important mechanism triggering apoptosis, and CD95L expression has recently been implicated for immune evasion and aggressive behavior in malignancies. This study aimed to investigate CD95 and CD95L expression in lymphomas and the possible relationship with tumor cell apoptosis, with emphasis on the natural killer (NK) cell lymphomas, which are highly aggressive neoplasms and frequently exhibit tumor cell apoptosis/necrosis. Frozen sections of 82 cases of lymphomas obtained from Queen Elizabeth Hospital and Caritas Medical Center, Hong Kong, were immunostained with polyclonal anti-CD95 and anti-CD95L antibodies. The NK-cell lymphomas were also studied for apoptosis by in situ end labeling (ISEL) method, and zonal tumor cell death was evaluated semiquantitatively. The cases studied included 27 NK-, 22 T-, and 33 B-cell lymphomas. CD95 was expressed in 25 (93%) NK-, 11 (50%) T-, and 14 (42%) B-cell lymphomas. CD95L was expressed in 19 (70%) NK-, 15 (68%) T-, and 3 (9%) B-cell lymphomas. There was significant difference in the frequency of CD95 expression between B- and NK- (P < .001), and between T- and NK-cell lymphomas (P < .05), and in CD95L expression between B- and T- (P < .01) or NK-cell (P < .01) lymphomas. Zonal tumor cell death was present in 21 (78%) NK-cell lymphomas and 1 (4.5%) T-cell lymphoma and showed no correlation with CD95 or CD95L expression. ISEL analysis showed apoptosis predominantly in the viable areas in only 5 (24%) NK-cell lymphomas. In conclusion, CD95L is frequently expressed in NK- and T-cell lymphomas, but rarely in B-cell lymphomas. Zonal tumor cell death is not correlated with CD95 or CD95L expression and thus the CD95/CD95L system probably does not contribute significantly to this phenomenon. We postulate that the frequent expression of CD95L by NK- and T-cell lymphomas may mediate local or systemic tissue damage and immune evasion, and may contribute to the clinical aggressiveness of these tumors.

Medium-term results of percutaneous, arthroscopically-assisted osteosynthesis of fractures of the tibial plateau

We carried out percutaneous, arthroscopically- and fluoroscopically-assisted osteosynthesis of fractures of the tibial plateau in 52 patients, of whom 38 were assessed using the HSS knee score and standing radiographs. We reviewed 31 AO type-B fractures and seven type-C fractures after a mean follow-up of five years (1 to 14). Fixation was achieved using percutaneous screws and/or an external frame; 33 associated intra-articular injuries, diagnosed in 21 out of the 38 patients, were treated arthroscopically. Subjectively, 94.7% of the patients reviewed were satisfied. According to the HSS knee score 78.9% of the results were excellent, 13.2% good, 7.9% fair and none was poor. Narrowing of the joint space was found in 28.9% of the injured and 5.3% of the unaffected knees and axial deviation of 5 degrees to 10 degrees in 15.8% of the injured and 10.5% of the unaffected knees. Of the 52 fractures, reduction was incomplete in one, and in two secondary displacement occurred, of which one required corrective osteotomy. Deep-venous thrombosis occurred in four cases. The technique has proved to be safe but demanding. It facilitates diagnosis and appropriate treatment of associated intra-articular lesions.

Costochondral junction fractures and intra-abdominal trauma in non-accidental injury (child abuse)

Rib fractures are a common skeletal manifestation of non-accidental injury (NAI) in infants and young children and are generally considered to be highly specific for abuse. There are, however, relatively few descriptions of fractures involving the costochondral junctions in NAI. We present three children (two boys, one girl; 7, 18, and 36 months of age) with anterior rib fractures which involved the sixth to ninth costochondral junctions. The fractures were bilateral in two children and symmetrical in one. They had appearances analogous to 'bucket handle' metaphyseal fractures of long bones. They were difficult to visualise and healed with minimal callus formation. These fractures were associated with major abdominal visceral injuries, which in themselves carry a significant morbidity and mortality. The importance of recognising such fractures is highlighted.

Acute Wernicke's encephalopathy complicating chronic gallstone ileus

An autopsy performed on a 53-year-old man who had unrelieved obstruction of the small bowel due to gallstone ileus revealed morphological features that were typical of acute Wernicke's encephalopathy. The likely sequence of disease in this patient was the development of thiamine deficiency owing to the unrelieved intestinal obstruction, which resulted in the development of acute Wernicke's encephalopathy. A high clinical awareness is required for the diagnosis of acute Wernicke's encephalopathy in patients with malnutrition from any cause.

Correlation of CT with histopathological findings in patients with gastric and gastro-oesophageal carcinomas following neoadjuvant chemotherapy

Gastric carcinoma is the fourth commonest cause of death from malignant disease in United Kingdom. In the Western hemisphere, it usually presents with advanced disease, which contributes to its very poor prognosis. Pre-operative (neoadjuvant) chemotherapy offers the possibility of down-staging such tumours and the potential to render tumours operable. Computed tomography (CT) plays a central role in the assessment of patients presenting with the disease, and in those who undergo chemotherapy, in evaluating their response.

OBJECTIVE

This study was undertaken to evaluate the role of CT in predicting loco-regional spread of tumour following neoadjuvant chemotherapy in non-metastatic gastric and gastro-oesophageal cancers.

METHODS AND MATERIALS

We correlated CT evidence of loco-regional spread with pathological findings following surgery in 21 patients who received pre-operative chemotherapy.

RESULTS

Residual masses were seen on CT in 19 patients, and 15 contained active tumour, although in four patients no viable tumour was demonstrated at histopathology. The overall accuracy of CT in assessing loco-regional disease was disappointing with sensitivities, specificities, positive and negative predictive values of 57%, 43%, 75% and 33%, respectively.

CONCLUSIONS

We conclude that CT is not accurate in identifying residual loco-regional spread and therefore should not preclude surgery in those patients who have received neoadjuvant chemotherapy.

Radiologically guided bone biopsy: results of 502 biopsies

PURPOSE

To analyze the results of 502 biopsies over a 19-year period for the purpose of highlighting the results that can be expected from such a large study, with emphasis on needle choice and anesthetic methods.

METHODS

The histological, cytological, and microbiological results of 477 patients who had 502 bone biopsies carried out between July 1977 and March 1996 were studied. Less than 5% of patients required second biopsies. There were almost equal numbers of males and females in the group. The lesions were visible radiologically and most of the biopsies were carried out by a single operator. The lesions were classified on their histopathological, cytopathological, and microbiological findings.

RESULTS

Tumors accounted for 40% of the biopsies, and infection for 16%. Biopsies which did not yield a "positive" diagnosis accounted for 31%; these included specimens reported as normal, or as showing reactive changes, repair, remodelling, non-specific features, inflammation (but not clearly infective), or no evidence of malignancy or inflammation. Less than 4% of biopsies were incorrect, and some of these were re-biopsied.

CONCLUSION

Bone biopsy is a valuable technique for positive diagnosis of malignancy or infection, as it enables a definitive plan for treatment and management of patients to be established. Exclusion of serious pathology is almost equally important. In principle, any osseous site can be biopsied using fluoroscopic or computed tomographic guidance. Care in the biopsy technique and selection of the bone needle is required.

Primary non-Hodgkin's lymphoma of the nose and nasopharynx: clinical features, tumor immunophenotype, and treatment outcome in 113 patients

PURPOSE

To study the clinical features and outcome for primary non-Hodgkin's lymphomas of the nose/nasopharynx (NNP-NHLs) according to immunophenotype.

PATIENTS AND METHODS

One hundred thirteen Chinese patients with primary NNP-NHLs that belonged to the categories E, F, G, or H according to the Working Formulation (WF), with full immunophenotypic data and complete clinical follow-up data, were analyzed in this retrospective study.

RESULTS

Ninety (79.6%) patients had localized (stage I or II) disease, while 23 (20.4%) had stage III or IV disease. The lymphomas in 51 (45.1%), 24 (21.3%), and 38 (33.6%) patients showed natural killer (NK)/T- (CD56-positive), T-cell, and B-cell immunophenotype, respectively. Seventy-three patients (65.8%) achieved a complete remission, of whom 34 (46.6%) subsequently relapsed. The median follow-up time for those alive was 88 months. The 5-year actuarial disease-free and overall survival rates were 34.4% and 37.9%, respectively. Multivariate analysis showed that only stage and immunophenotype were significant for survival. NK/T lymphomas were distinctive among the three immunophenotypes in the following aspects: the highest male-to-female ratio, more frequent involvement of the nasal cavity alone, higher risk of dissemination to the skin, more frequent development of hemophagocytic syndrome, and the worst prognosis (overall median survival, 12.5 months).

CONCLUSION

The three immunophenotypes studied are shown to exhibit different clinical patterns. Since the NK/T phenotype carries the worst prognosis, patients who present with NNP-NHL should have their tumors analyzed for CD56 expression.

Intravascular lymphomatosis: a case presenting with encephalomyelitis and reactive haemophagocytic syndrome diagnosed by renal biopsy

AIMS

To report an unusual instance of intravascular lymphomatosis presented with encephalomyelitis and reactive haemophagocytic syndrome. There was no skin involvement. The diagnosis was made on a renal biopsy.

METHODS AND RESULTS

The marrow smear was air dried and stained with Diff-Quik. The tissue sections were stained with haematoxylin and eosin. Masson trichrome, periodic acid-Schiff's reagent, Elastic van Gieson's stain, modified hexamine-silver technique and Martius scarlet blue. Immunohistochemistry for CD45, CD20, CD45RO, Factor VIII related antigen, CD31 and CD34 was performed on paraffin-processed tissue. The marrow smear showed active haemophagocytosis in the histiocytes. The renal biopsy showed intravascular lymphomatosis with tumour cells positive for CD45 and CD20.

CONCLUSION

The possibility of intravascular lymphomatosis should be considered in patients with reactive haemophagocytic syndrome where the underlying cause cannot be found after thorough investigation.

CD56+ putative natural killer cell lymphomas: production of cytolytic effectors and related proteins mediating tumor cell apoptosis?

Apoptosis is a regulated form of cell death that may be triggered by natural killer (NK) or cytotoxic T cells, which effect target cell lysis by cytolytic effector and related proteins through complex intracellular signals. This study was aimed to investigate whether there is selective expression of these cytolytic markers in the putative NK-cell lymphomas and whether there is correlation with zonal tumor cell death in these tumors. Expression of the cytolytic effectors perforin, granzyme B9, and the granule membrane protein TIA1 were examined in 24 putative NK-cell lymphomas, 18 postthymic T-cell lymphomas (one case CD8+ CD56+ and three anaplastic large cell lymphomas (ALCL), three T-lymphoblastic lymphomas, and 20 B-cell lymphomas. Nineteen (79%) putative NK-cell lymphomas expressed perforin, and all 24 cases expressed granzyme B9 and TIA1. The only CD8+ CD56+ postthymic T-cell lymphoma also expressed all three cytolytic markers, two CD8- ALCL expressed TIA1; other postthymic T-cell, T-lymphoblastic, and B-cell lymphomas were consistently negative. There was strong correlation between percentage perforin-positive cells and zonal tumor cell death. Angioinvasion, in contrast, was present only in a proportion (37%) of these lymphomas despite the frequent presence of zonal tumor cell death (71%). We propose that cytolytic effector and related proteins produced by putative NK and some CD8+ CD56+ postthymic T-cell lymphomas, probably in conjunction with other mechanisms, may effect massive tumor cell apoptosis. The frequent expression of cytolytic effector markers in the CD2+ surface CD3- CD56+ putative NK-cell lymphomas lends further support to their probable NK cell origin.

The investigation of renovascular hypertension in children: the accuracy of radio-isotopes in detecting renovascular disease

Renovascular disease is an important cause of hypertension in children because it is potentially treatable by surgical or angioplasty techniques. The aim of this study was to assess the accuracy of radio-isotopes (DMSA, DTPA and MAG3) combined with the angiotensin converting enzyme inhibitor, captopril, in detecting children with renovascular hypertension. We retrospectively reviewed the ultrasound and pre- and post-captopril radionuclide studies (either DMSA and/or DPTA and/or MAG3) of children with sustained hypertension investigated at our institution. Renal angiography was used as the 'reference technique'. Thirty-nine children, over a period of 10 years, were evaluated: 17 (44%) children had renovascular disease that involved the proximal three divisions of the renal arteries, some of which were amenable to treatment. The overall sensitivity, specificity, positive predictive value and negative predictive value for detecting such renovascular disease, as assessed by changes between pre- and post-captopril radio-isotope studies, were disappointing at 59%, 68%, 59% and 68%, respectively. When considering only abnormalities in post-captopril studies, these indices were 82%, 41%, 52% and 75%, respectively. Three children with potentially treatable renovascular disease were not identified on the captopril studies. We conclude that renal angiography should remain the 'reference technique' in identifying children suspected of renovascular hypertension.

Gastric malignant schwannoma in a child

Malignant schwannoma (malignant peripheral nerve sheath tumour, MPNST) is a high grade sarcoma with a potential for local recurrence and distant metastasis that may occur at any site in the body where there is neural tissue. MPNST is rare in children and is unreported in the stomach in the paediatric age group. MPNST presents either as an expanding mass, with or without pain, or in the gastrointestinal tract with haemorrhage or obstruction. Many cases occur without evidence of neurofibromatosis but thers is a reported association between MPNST and neurofibromatosis of up to 50%. MPNST has a higher incidence at sites of previous irradiation. Treatment is by complete surgical excision. Radiology is of value in initial diagnosis and staging prior to surgery. The definitive diagnosis is made on the histopathological appearance and immunohistochemical profile. The findings on barium meal, abdominal ultrasound and CT are presented.

Nonnasal lymphoma expressing the natural killer cell marker CD56: a clinicopathologic study of 49 cases of an uncommon aggressive neoplasm

Expression of the natural killer (NK) cell antigen CD56 is uncommon among lymphomas, and those that do are almost exclusively of non-B-cell lineage and show a predilection for the nasal and nasopharyngeal region. This study analyzes 49 cases of nonnasal CD56+ lymphomas, the largest series to date, to characterize the clinicopathologic spectrum of these rare neoplasms. All patients were Chinese. Four categories could be delineated. (1) Nasal-type NK/T cell lymphoma (n = 34) patients were adults 21 to 76 years of age (median, 50 years), including 25 men and 9 women. They presented with extranodal disease, usually in multiple sites. The commonest sites of involvement were skin, upper aerodigestive tract, testis, soft tissue, gastrointestinal tract, and spleen. Only 7 cases (21%) apparently had stage I disease. The neoplastic cells were often pleomorphic, with irregular nuclei and granular chromatin, and angiocentric growth was common. The characteristic immunophenotype was CD2+ CD3/Leu4- CD3epsilon+ CD56+, and 32 cases (94%) harbored Epstein-Barr virus (EBV). Follow-up information was available in 29 cases: 24 died at a median of 3.5 months; 3 were alive with relapse at 5 months to 2.5 years; and 2 were alive and well at 3 and 5 years, respectively. (2) Aggressive NK cell leukemia/lymphoma (n = 5) patients presented with hepatomegaly and blood/marrow involvement, sometimes accompanied by splenomegaly or lymphadenopathy. The neoplastic cells often had round nuclei and azurophilic granules in the pale cytoplasm. All cases exhibited an immunophenotype of CD2+ CD3/Leu4- CD56+ CD16- CD57- and all were EBV+. All of these patients died within 6 weeks. (3) In blastoid NK cell lymphoma (n = 2), the lymphoma cells resembled those of lymphoblastic or myeloid leukemia. One case studied for CD2 was negative and both cases were EBV-. One patient was alive with disease at 10 months and one was a recent case. (4) Other specific lymphoma types with CD56 expression (n = 8) included one case each of hepatosplenic gammadelta T-cell lymphoma and S100 protein+ T-cell lymphoproliferative disease and two cases each of T-chronic lymphocytic/prolymphocytic leukemia, lymphoblastic lymphoma, and true histiocytic lymphoma. All of these cases were EBV-. Six patients died at a median of 6.5 months. Nonnasal CD56+ lymphomas are heterogeneous, but all pursue a highly aggressive clinical course. The nasal-type NK/T-cell lymphoma and aggressive NK cell leukemia/lymphoma show distinctive clinicopathologic features and a very strong association with EBV. Blastoid NK cell lymphoma appears to be a different entity and shows no association with EBV.

Evaluation by magnetic resonance imaging of the inferior vena cava in patients with non-seminomatous germ cell tumours of the testis metastatic to the retroperitoneum

OBJECTIVE

To assess the role of magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) in evaluating suspected occlusion of the inferior vena cava (i.v.c.) in patients with abdominal nodal metastases from non-seminomatous germ cell tumours, thus giving information that may be helpful in planning surgery and for determining the need for anticoagulant therapy.

PATIENTS AND METHODS

Five patients with abdominal nodal metastases in whom occlusion of the i.v.c. was suspected on computed tomography (CT) were imaged using a 1.5 T MRI scanner. The MRI findings were compared with those from CT.

RESULTS

The MR images successfully and clearly detected partial and total occlusions of the i.v.c. by both intraluminal thrombus and extrinsic compression. The technique also clearly detected extensive collateral venous circulation in several cases and in one a cavernous transformation of the i.v.c. In all patients, the MRI studies provided better information than that from CT.

CONCLUSION

MRI, and particularly MRA, is a comparatively new technique that is non-invasive and offers the potential of evaluating vascular structures with no need for ionizing radiation or contrast media. This technique, if available, should be chosen for imaging the i.v.c. in patients suspected of having compression or occlusion of the i.v.c.

Redefining the genital abnormality in the Robinow syndrome. -004

PURPOSE

We defined the anatomical structure of the male genital abnormality in the Robinow syndrome. Features of this syndrome include mesomelic brachymelia of the arms, bifid terminal phalanges of the hands and feet, characteristic facies, skeletal anomalies and hypoplastic external genitalia.

MATERIALS AND METHODS

Penile anatomy of 3 patients with the Robinow syndrome was assessed using computerized tomography and magnetic resonance imaging. Results were compared to those of 4 controls who underwent imaging for pelvic malignancies.

RESULTS

Cross-sectional imaging showed that normal penile crura were inserted onto the anteromedial aspect of the pubic bone. In contrast, in the Robinow syndrome they were inserted inferiorly and posteriorly onto the medial aspect of the ischial tuberosity. In addition, the crura in the Robinow syndrome extended posterior to a line intersecting both femoral shafts. Compared to controls, there was a significant gap between the symphysis pubis and dorsal aspect of the penis.

CONCLUSIONS

The penile anomaly in the Robinow syndrome is due to abnormal insertion of the penile crura, resulting in a penis that appears shorter and more inferiorly placed between the legs.

Validation of a high-performance liquid chromatographic assay method for pharmacokinetic evaluation of busulfan

The development and validation of a high-performance liquid chromatographic (HPLC) assay for determination of busulfan concentrations in human plasma for pharmacokinetic studies is described. Plasma samples containing busulfan and 1,6-bis(methanesulfonyloxy)hexane, and internal standard, were prepared by derivatization with sodium diethyldithiocarbamate (DDTC) followed by addition of methanol and extraction with ethyl acetate. The extract was dried under nitrogen and the samples reconstituted with 100 microl of methanol prior to HPLC determination. Chromatography was accomplished using a Waters NovaPak octadecylsilyl (ODS) (150 x 3.9 mm I.D.) analytical column, NovaPak ODS guard column, and mobile phase of methanol-water (80:20, v/v) at a flow-rate of 0.8 ml/min with UV detection at 251 nm. The limit of detection was 0.0200 microg/ml (signal-to-noise ratio of 6) with a limit of quantitation (LOQ) of 0.0600 microg/ml for busulfan in plasma. Calibration curves were linear from 0.0600 to 3.00 microg/ml in plasma (500 microl) using a 1/y weighting scheme. Precision of the assay, as represented by C.V. of the observed peak area ratio values, ranged from 4.41 to 13.5% (13.5% at LOQ). No day-to-day variability was observed in predicted concentration values and the bias was low for all concentrations evaluated (bias: 0 to 4.76%; LOQ: 2.91%). The mean derivatization and extraction yield observed for busulfan in plasma at 0.200, 1.20 and 2.00 microg/ml was 98.5% (range 93.4 to 107%). Plasma samples containing potential busulfan metabolites and co-administered drugs, which may be present in clinical samples, provided no response indicating this assay procedure is selective for busulfan. This method was used to analyze plasma concentrations following administration of a 1 mg/kg oral busulfan dose.

Combination of "patch, drain, and wait" and home total parenteral nutrition for midgut volvulus with massive ischemia/necrosis

The successful use of a combination of "patch, drain, and wait" (PDW) and home total parenteral nutrition (TPN) in the management of a case of acute, catastrophic midgut volvulus in a 2-year-11-month-old boy with near-total ischemia/necrosis of his small intestine is reported. The PDW approach to the highly effective management of acute midgut ischemia/necrosis in infancy and childhood (necrotizing enterocolitis and midgut volvulus) involves maximum gut salvage by avoidance of resection, stoma formation, or both through the use of extensive peritoneal cavity drainage by Penrose drains, TPN, and broad-spectrum antibiotics. The extensive peritoneal drainage fosters capture of enteric fistulas with the formation of enterostomies at drain exit sites, while adhesions and ischemia/inflammation-induced hypervascular obliteration of the peritoneal cavity diminish the potential for peritonitis (no peritoneal cavity, no peritonitis) and facilitate impressive salvage of seemingly hopelessly lost ischemic/necrotic gut (a simulation of the in utero ischemic gut process leading to atresias and some varying, but generally mild, gut loss) while simultaneously contributing to the resorption of absolutely non-salvageable gut and the creation of a remarkably clean and adhesion-free peritoneal cavity resembling that of a newborn infant with midgut intestinal atresia.

T- and T/natural killer-cell lymphomas of the salivary gland: a clinicopathologic, immunohistochemical and molecular study of six cases

Primary salivary gland lymphomas are almost always of B lineage, with most being represented by low grade B-cell lymphoma of mucosa-associated lymphoid tissue. This study characterizes the rare non-B-cell lymphomas of the salivary gland based on an analysis of six cases. All patients were men, with a mean age of 53.5 years. They presented with submandibular or parotid mass, which on histological examination showed extensive interstitial infiltration by small, medium-sized, or large lymphoid cells. There was prominent invasion and expansion of the ducts and acini in five cases. Angioinvasion was evident in two cases. Three cases were of T lineage and were CD56 negative; one of these cases expressed CD30. Three cases showed an immunophenotype of CD2+ CD3(f)- CD3(p)+ CD56+, consistent with T/natural killer (NK) cell lymphoma. In situ hybridization for Epstein-Barr virus (EBV)-encoded early nuclear RNA (EBER) showed positive reaction exclusively in the three CD56+ cases. Clonal T-cell populations were shown in two CD56-negative cases by polymerase chain reaction on paraffin sections using primers for the T-cell-receptor (TCR) gamma-chain gene, but not in the other four cases (the three CD56+ cases and one CD56- case). Four patients (two CD56+ and two CD56-) died within 3 years, and two were disease free at 4 and 1.5 years, respectively. This study shows that salivary gland T- or T/NK-cell lymphomas cannot be reliably distinguished from B-cell lymphomas on morphological grounds alone, because both can show prominent lymphoepithelial lesions. It appears that T/NK-cell lymphomas, which are often extranodal in localization and strongly associated with Epstein-Barr virus (EBV), show a predilection to involve the salivary glands as well.

Aggressive T/natural killer cell lymphoma presenting as testicular tumor

BACKGROUND

Nonnasal CD56+ T/natural killer (NK) cell lymphomas with morphologic and immunogenetic features similar to those of the distinctive nasal T/NK cell lymphoma are uncommon and have been characterized only recently. They show predominantly extranodal presentation, high stage disease, a highly aggressive course, strong association with Epstein-Barr virus (EBV), and lack of T cell receptor gene rearrangement. Only one previously reported case had a testicular presentation, although the testis is not uncommonly involved during the course of disease in both nasal and nonnasal T/NK cell lymphomas.

METHODS

Three patients with T/NK cell lymphoma who presented initially with a testicular mass are reported.

RESULTS

The three patients underwent orchidectomy for testicular tumor. Histologically, the testes showed diffuse dense infiltration of medium-sized or large lymphoma cells. Antiocentric growth and necrosis were prominent in two cases. The lymphoma had the following immunophenotype: CD2+ CD3 epsilon+ CD56+ compatible with T/NK cell lymphoma; two lacked staining with Leu4 (CD3), and one had weak staining. With immunohistochemical preparations, it was noted that the rete testis stained consistently for CD56, and the Leydig cells and Sertoli cells showed patchy staining. The neoplastic cells harbored EBV, as demonstrated by in-situ hybridization. Additional sites of disease were detected at the time of the diagnosis in one patient (nose) or appeared soon afterwards in all three patients (skin or gastrointestinal tract). All three patients died within 5 months.

CONCLUSIONS

This study confirms that testicular CD56+ T/NK cell lymphoma tends to disseminate early, pursues an aggressive course, and is strongly associated with EBV. CD56 recognizes the neural cell adhesion molecule (NCAM), which exhibits homophilic binding properties. The expression of CD56 in the normal testicular constituents can perhaps explain the tendency for T/NK cell lymphoma to localize in this organ.

Utility of a paraffin section-reactive CD56 antibody (123C3) for characterization and diagnosis of lymphomas

Although expression of CD56 (neural cell adhesion molecule, a natural killer cell marker) is uncommon among lymphomas, this feature has defined a distinctive and important category of lymphoma: the putative natural killer (NK) cell lymphoma, which shows a predilection for the upper aerodigestive tract, skin, skeletal muscle, and other extranodal sites and pursues an aggressive clinical course. Thus far, CD56 expression can be reliably analyzed only on fresh or frozen tissues. In this study, we evaluated the sensitivity and specificity of a CD56 antibody, 123C3, when applied on routine formalin-fixed, paraffin-embedded tissues for analysis of lymphomas, by comparing the staining results with those obtained on frozen tissues using the CD56 antibody NKH1. The 123C3 antibody worked on paraffin sections only with prior antigen retrieval using a pressure cooker or a microwave oven. Among 32 CD56+ T/NK cell lymphomas and one CD56+ B-lymphoblastic lymphoma, the neoplastic cells showed crisp membrane staining with 123C3 in all cases. None of the 24 CD56- T-cell lymphomas and 50 CD56-B-cell lymphomas stained with 123C3. In normal or reactive lymphoid tissues from a variety of sites, there were few small lymphocytes (< 0.1%) that showed cell membrane staining with 123C3, although occasional plasma cells might show cytoplasmic staining. We conclude that with suitable antigen retrieval procedures, 123C3 can be reliably applied on routine paraffin sections for detection of CD56 expression in lymphomas. Furthermore, this antibody can be used to support a diagnosis of lymphoma or to detect residual disease for cases of CD56+ T/NK cell lymphoma in which the neoplastic lymphoid cells are small and show minimal atypia, especially in small biopsies.

Hepatosplenic gamma delta T-cell lymphoma. A distinctive aggressive lymphoma type

The T-cell receptor (TCR) expressed on the surface of most T-lymphocytes is of alpha beta type, and only a minority bear the gamma delta-TCR. Similarly, postthymic T-cell lymphomas rarely express gamma delta-TCR. Hepatosplenic gamma delta T-cell lymphoma is an uncommon entity that has so far not been widely recognized. We report one such case that has been comprehensively studied by multiple modalities and showed the unique occurrence of leukemic picture at presentation. The 39-year-old man presented with fever, marked weight loss, and massive splenomegaly. Peripheral blood showed thrombocytopenia and a white cell count of 5.8 x 10(9)/l, with 66% medium-sized lymphoid cells that had a round or folded nucleus, condensed chromatin and a moderate amount of pale blue cytoplasm. Splenectomy was performed and histologic examination of the spleen, bone marrow, liver, and abdominal lymph nodes demonstrated lymphoma infiltration with a predominantly sinusoidal pattern. Immunohistochemical studies of the lymphoma cells showed a T-cell phenotype: CD2+ CD3+ CD5+ CD7+ gamma delta-TCR+ alpha beta-TCR- CD56+ CD4- CD8- CD16- CD57-. Cytogenetic studies showed complex clonal chromosomal abnormalities of 44,X, -Y, -11, -22, + mar in 3/16 cells. Rearrangement of the TCR gamma chain gene was demonstrated by polymerase chain reaction; the TCR beta chain gene was partially chain reaction; the TCR beta chain gene was partially rearranged. The patient did not respond to single agent chemotherapy, but achieved clinical remission with combination chemotherapy. Based on the available data in the literature, hepatosplenic gamma delta T-cell lymphoma exhibits distinctive clinicopathologic features, and probably represents the neoplastic counterpart of splenic gamma delta T-lymphocytes. This disease is associated with a poor prognosis and usually relapses despite initial response to chemotherapy.

A study of the association of Epstein-Barr virus with Burkitt's lymphoma occurring in a Chinese population

There is a strong association (approximately 95%) of endemic Burkitt's lymphoma with Epstein-Barr virus (EBV), whereas the association is weak for the sporadic form occurring in Western countries (approximately 15%). In the Middle East, North Africa and South America, 60-80% of Burkitt's lymphomas harbour EBV. These epidemiological differences suggest that either the endemicity of EBV or socio-economic conditions, or both, may influence the pathogenetic role of EBV in Burkitt's lymphoma. Since only meagre data are available on Asians, this study was performed to address this issue by studying cases from Hong Kong, where EBV seroconversion occurs in the first few years of life but the socio-economic conditions approach those of Western countries. In situ hybridization for EBV encoded RNAs (EBERs) was performed on paraffin sections of 18 cases of Burkitt's lymphoma. Labelling of the neoplastic cells was detected in five cases (27.7%). In contrast, among 54 cases of B-cell lymphomas of various subtypes studied for comparison, signals for EBER were detected in only one case each of T-cell-rich large B-cell lymphoma, anaplastic large cell lymphoma and Reed-Sternberg-like cells occurring in B-cell chronic lymphocytic leukaemia/small lymphocytic lymphoma. The strong labelling with oligo-dT probe (which hybridized with the polyadenylated ends of mRNA) in all cases suggested that the negative results were genuine and not due to poor preservation of RNA in the tissues. Thus, among B-cell neoplasms occurring in Chinese, Burkitt's lymphoma shows a statistically stronger association (P < 0.01) with EBV than with other types of B-cell lymphoma.(ABSTRACT TRUNCATED AT 250 WORDS)

Coccoid forms of Helicobacter pylori in the human stomach

Helicobacter pylori (HP) may transform from helical bacillary forms to coccoid forms after several days' in vitro incubation. The authors examined 111 consecutive gastrectomy specimens for the presence of coccoid forms of H pylori. Tissues from 64 stomachs (57.7%) showed colonization by H pylori, including 49 cases (76.6%) of adenocarcinoma, 14 cases (21.9%) of benign peptic ulcer, and 1 case (1.6%) of malignant lymphoma. Of these, coccoid forms of H pylori were identified in 53 cases (82.8%). In hematoxylin-and-eosin-stained sections coccoid forms of H pylori appeared as solid, round, basophilic dotlike structures. Under an electron microscope, coccoid forms of H pylori appeared as U-shaped bacilli, with the ends of the two arms joined by a membranous structure. Ultrastructural findings were identical to those from cultures of H pylori. With anti-Helicobacter antibody, coccoid forms of H pylori were positively stained by immunoperoxidase. Helical bacillary forms of H pylori invariably coexisted with the coccoid forms. By semiquantitative analysis, the number of coccoid forms in adenocarcinoma was significantly (P > .01) greater than that in benign peptic ulcers. This study confirms that H pylori can exist in coccoid forms in the human stomach. Coccoid forms should be distinguished from the pathogenic or nonpathogenic bacterial cocci, fungal spores, and cryptosporidia that may colonize the human stomach.

Epstein-Barr virus-associated gastric lymphoma in Hong Kong Chinese

We report 11 cases of gastric lymphoma that harbor the Epstein-Barr virus (EBV) encoded small messenger RNA, EBER-1, detected by in situ hybridization. The cases represented 18% of 61 consecutive gastric lymphomas from three institutions in Hong Kong between 1988 and 1993. The mean age of patients was 62 years (range, 33 to 87). The male to female ratio was 5:6. Nine of the 11 (81.8%) EBER-1+ gastric lymphomas were diffuse large cell lymphomas of B-cell type without low grade components. Macroscopically these lymphomas appeared either as large noncleaved cell (centroblastic) or immunoblastic type. From the available follow-up data, five of the nine patients with B-cell lymphoma were alive and well 48, 40, 14, 13, and 12 months, respectively, after gastrectomy and chemotherapy. One patient died of postoperative pneumonia and one died of a second malignancy (esophageal squamous carcinoma) 40 months after gastrectomy. None of the EBER-1+ B-cell gastric lymphomas showed histological features characteristic of low grade lymphoma of the mucosa-associated lymphoid tissue (MALT) type reported to be common in some Western countries. Of the two patients with T-cell lymphoma, one had a pleomorphic T-cell lymphoma and the other had an angiocentric lymphoma. The former was lost to follow-up after the biopsy and the latter presented with gastric perforation and died 1.5 months after gastrectomy. It is concluded that a significant proportion of gastric lymphomas in Hong Kong Chinese are EBV-related and that they show histological features more akin to conventional node-based lymphomas than to MALT-type lymphomas.

Detection of Epstein-Barr viral RNA in malignant lymphomas of the upper aerodigestive tract

Recent studies have suggested a probable etiologic association between Epstein-Barr virus (EBV) and nasal lymphomas, irrespective of geographic location. This study was performed to investigate the strength of association of EBV with non-Hodgkin's lymphomas of the upper aerodigestive tract, based on a large series of cases that have been thoroughly immunophenotyped on frozen tissues. A sensitive in situ hybridization technique was used to detect EBV encoded RNA (EBER) in paraffin sections. Among 30 cases of nasal/nasopharyngeal T-cell lymphoma, 25 (83.3%) were EBER-positive. In the positive cases, most of the neoplastic cells showed strong nuclear signals. Further analysis of this group of tumors showed that all 21 cases (100%) with a CD56+ CD3-phenotype were EBER positive, whereas four of nine cases (44.4%) with a CD56-negative immunophenotype were positive. Only one of 10 cases (10%) of nasal/nasopharyngeal B-cell lymphoma was EBER positive; the positive case was a diffuse mixed-cell lymphoma and could not be distinguished morphologically from the negative cases. Among the 21 cases of lymphoma of the tonsils and back of the tongue (20 B-lineage and one T-lineage), none was EBER positive. In the normal mucosa of the nose/nasopharynx or tonsil (20 cases studied), only very rare EBER-positive small lymphocytes were found in two cases. The almost exclusive detection of EBER in nasal/nasopharyngeal T-cell neoplasms among the lymphomas of the upper aerodigestive tract suggests that EBV probably plays an etiologic role in the pathogenesis of this group of tumors and is not simply a passenger virus, and neither is this merely a site-dependent phenomenon in view of the weak association with nasal/nasopharyngeal B-cell lymphoma.

In situ localization of Epstein-Barr virus encoded RNA in non-nasal/nasopharyngeal CD56-positive and CD56-negative T-cell lymphomas

We recently reported a group of non-nasal/nasopharyngeal hematolymphoid malignancies expressing the natural killer cell marker CD56, characterized by frequent extranodal localization, angiocentricity, and aggressive clinical course (HUM PATHOL 23:798-804, 1992). Because we have shown a very strong association of Epstein-Barr virus (EBV) with CD56-positive T-cell lymphomas of the nose nasopharynx, we asked whether a similar association also occurs with the non-nasal CD56-positive T-cell lymphomas. In situ localization of EBV encoded RNA (EBER) was performed on paraffin sections of 15 such cases, including the nine previously reported cases and six new cases (three showing prominent hepatosplenic involvement and three showing involvement of one or more extranodal sites, such as the parotid gland, tonsils, gastrointestinal tract, skeletal muscle, and testis). A case was considered positive when the majority of the tumor cells showed nuclear signal. Ten cases showed EBER positivity, and all but one of them were negative for CD3 and other T-cell markers, except CD2. Only one of four cases showing a CD3-positive phenotype was EBER positive. Of the remaining two CD3-negative EBER-negative cases, one showed a histiocytic phenotype and the other was positive for multiple T-cell markers. Among 15 cases of CD56-negative non-nasal peripheral T-cell lymphoma studied for comparison, six were CD3-negative, among which three showed EBER positivity. All nine CD3-positive cases were EBER negative. Five cases (three CD3 positive and two CD3 negative) showed rare isolated (< 1%) EBER-positive tumor cells. We conclude that among non-nasal T-cell lymphomas, EBV is strongly correlated with CD56 positivity (66.7% v 20%), and the positive cases almost always show an immunophenotype identical to that commonly observed in nasal lymphomas (CD2 positive, CD3 negative, and CD56 positive). Thus, EBV may play an etiologic role in these CD56-positive lymphomas. There is also a correlation between EBER positivity and CD3 negativity, irrespective of the CD56 status. The presence of isolated EBER-positive cells in CD56-negative T-cell lymphomas, occurring at a frequency similar to that reported in the European population, probably represents secondary infection of tumor cells.

CD56 (NCAM)-positive malignant lymphoma

CD56, a natural killer cell marker reactive with the neuronal-cell adhesion molecule (NCAM), identifies a group of lymphomas with distinctive clinicopathologic features. The disease affects mostly middle-aged adults who often present with fever, skin rash and hepatosplenomegaly in the absence of peripheral lymphadenopathy. Extranodal involvement is common, particularly the skin, aerodigestive tract and central nervous system. Histologically, an angiocentric and angiodestructive pattern of infiltrate is often seen, but the cytological spectrum of the lymphoma cells is very broad. Cytoplasmic granules, however, are frequently found when Giemsa-stained cytologic preparations are examined. Immunologically, CD56-positive lymphomas can be sub-classified into CD3-positive (T-cell) and CD3-negative (probably true natural killer cell) subtypes. T-cell receptor gene rearrangement can be demonstrated in the former cases, but not in the latter. Clinically, CD56-positive lymphomas are aggressive neoplasms.

Follicular dendritic cell tumor and vascular neoplasm complicating hyaline-vascular Castleman's disease

The localized form of hyaline-vascular Castleman's disease may rarely be complicated by a vascular neoplasm, which appears to arise in a background of vascular hyperplasia. We report a case complicated by follicular dendritic cell tumor, a hitherto undescribed occurrence that is expected from the presence of a "dysplastic" component of follicular dendritic cells in Castleman's disease. The patient had a large tumor mass in the mesocolon, associated with multiple small peritoneal deposits. The lesion showed typical histologic features of follicular dendritic cell tumor with storiform arrangement of spindly cells and admixture of small lymphocytes. The follicular dendritic cell nature of the tumor was confirmed by immunoreactivity with CD21 and CD35 antibodies and by ultrastructural demonstration of cell processes connected by desmosomes. Hyaline-vascular follicles were identified at the peripheral portion or occasionally scattered in the center of the tumor. Rarely, follicle-like structures were formed by tumor cells, possibly representing in situ malignant change. In addition, there was a small focus of vascular neoplasm comprising well-formed pericyte-rich small blood vessels devoid of cellular atypia. This report of the development of follicular dendritic cell tumor in Castleman's disease therefore completes the picture in that tumors corresponding to each cell type that proliferates in Castleman's disease have now been documented.

Nodular desmoplastic variant of trichoblastoma

A case of an unusual, previously unreported, nodular desmoplastic variant of trichoblastoma (hair germ neoplasm) in the scalp of a 65-year-old woman is reported. Four discrete nodules were present in close proximity at presentation. Another nodule developed in the same vicinity 3 1/2 years after excision, and there was no further recurrence 2 1/2 years later. The tumors were located in the dermis, made up of cords of primitive hair germ-like structures radiating down from discrete hyalinized nodules located in the superficial dermis. There were small foci of keratinization or mucoid change within the epithelial islands. Toward the deep portion of the tumor, the epithelial cells became spindly and grew in a more dispersed pattern, within a desmoplastic stroma. There was also infiltration of the epineurium of the cutaneous nerves and arector pili muscle. This uncommon benign neoplasm of hair germ merits wider recognition; in particular, this desmoplastic variant may mimic invasive carcinoma, morphea-type basal cell carcinoma, desmoplastic trichoepithelioma, and desmoplastic trichilemmoma. Distinguishing this variant from the former two possibilities is particularly important in order to avoid unduly aggressive treatment.

Odorant binding by a pheromone binding protein: active site mapping by photoaffinity labeling

The bacterially expressed recombinant pheromone binding protein (PBP) of Antheraea polyphemus was photoaffinity labeled with (6E,11Z)-[3H]hexadecadienyl diazoacetate, a photoactivatable analog of the naturally occurring acetate pheromone. Radiolabeled peptides were separated from an endoproteinase Lys-C digestion by HPLC and characterized by Edman degradation. The label was exclusively found in the Asp39-Lys58 fragment. Cleavage of this peptide (DDYVMTDRLAGCAINCLATK) with Arg-C gave a single radiolabeled peptide (DDYVMTDR), which was predicted to be alpha-helical. The adjoining LAGCAINCLATK fragment, which is highly conserved in PBP sequences, was predicted to be a hydrophobic beta-strand and has been proposed to be important in recognition of the alkadienyl chain. Edman degradation confirmed the location of the covalently attached ligand at Thr44 of the smaller hydrophilic peptide. In addition, the synthesis of the newly identified pheromone component (4E,9Z)-tetradecadienyl acetate and its photoaffinity analog, (4E,9Z)-[3H]tetradecadienyl diazoacetate, is also described. Mapping of PBP photoaffinity labeled by (4E,9Z)-[3H]14:Dza revealed that the hydrophobic region Asp21-Lys38 adjacent to the primary binding domain Asp39-Lys58 contained a second modification site. The 14-carbon odorant molecule thus had two binding positions within the recognition site, while only a single binding position was available to the 16-carbon pheromone.

Kikuchi's lymphadenitis. A morphologic analysis of 75 cases with special reference to unusual features

Seventy-five cases of Kikuchi's lymphadenitis, a self-limiting pseudomalignant condition, were reviewed to determine the spectrum of histologic findings. There were 55 females and 20 males; ages ranged from 9 to 57 years (mean, 25.5). Most patients presented with cervical lymphadenopathy (68 cases). Associated clinical findings were fever (20/52) and leukopenia (15/33). Serum antinuclear antibodies were negative in 15 patients among 16 tested. Among 32 patients with follow-up information, 31 remained well, including one who developed recurrence after 2 years. One patient died of fatal myocardial disease during the active disease. Histologically, the lymph nodes showed paracortical hyperplasia, often associated with a starry-sky appearance resulting from interspersed histiocytes and immunoblasts. The consistent finding was the presence of variable-sized discrete or confluent nodules in the paracortex composed of the following: (a) karyorrhectic and eosinophilic granular debris; (b) histiocytes, many of which were phagocytic and possessed distinctive peripherally placed crescentic nuclei and voluminous cytoplasm containing eosinophilic or karyorrhectic debris (for which we propose the designation crescentic histiocytes), mixed with nonphagocytic histiocytes having twisted or reniform nuclei which were often centrally placed; (c) plasmacytoid monocytes, which were medium-sized cells with eccentrically placed round nuclei and amphophilic cytoplasm; and (d) variable numbers of immunoblasts, which sometimes showed atypia such as irregular nuclear foldings and coarse chromatin. Neutrophils were absent or very sparse. In some nodules, coagulative necrosis was present in the center (45 cases). Foamy histiocytes were found in 23 cases, and they predominated in 11. Small clusters of plasmacytoid monocytes were noted in the paracortex in 40 cases. Perinodal inflammation was a common finding, and perinodal involvement by the karyorrhectic process occurred in 15 cases. In addition, we found a number of previously unreported features. Signet-ring histiocytes with clear or homogeneous lightly amphophilic cytoplasm and nuclei compressed into thin crescents, found in seven cases, could mimic signet-ring cell adenocarcinoma. In three cases, some germinal centers were involved by the karyorrhectic process. Foci of lymphocyte-depleted fibrovascular organization were present in eight cases, probably representing the resolving phase of the karyorrhectic process. Despite the broad morphologic spectrum, the intermingling of the distinctive crescentic histiocytes, karyorrhectic debris, and plasmacytoid monocytes in the form of nodules, together with the paucity of neutrophils, are the consistent findings that should permit a confident histologic diagnosis of Kikuchi's lymphadenitis.

Follicular dendritic cell tumors of the oral cavity

Follicular dendritic cell tumors are uncommon, and all the reported cases have occurred as primary lymph node tumors. We report two cases in the oral cavity, one in the soft palate and one in the tonsil. The tumors were characterized by sheets, whorls, and storiform arrays of spindly and syncytial-appearing cells with oval nuclei, fine chromatin, distinct nucleoli, and occasional nuclear pseudoinclusions. Multinucleated forms were present and were prominent in one case. An unusual feature was the presence of irregular pseudovascular spaces, which could raise a concern for vascular neoplasm. Because the tumors showed cohesive growth and a sharp interface with the fibrous stroma, they could also be mistaken for carcinoma, sarcoma, or melanoma. After radiation therapy, the palatal tumor showed a greater degree of nuclear pleomorphism, numerous nuclear pseudoinclusions, and striking nuclear grooving and foldings, mimicking interdigitating reticulum cell tumors. The diagnosis in both cases was confirmed by immunoreactivity with CD21 and CD35 and by ultrastructural demonstration of interdigitating cell processes with desmosomes. Both tumors also showed unexpected immunoreactivity with muscle-specific actin. Follicular dendritic cell tumor merits wider recognition of its possible extranodal occurrence as well as its full morphological spectrum in order to better define its behavior.

Rehydration of air-dried smears with normal saline. Application in fluid cytology

Ninety fluid specimens (30 each of urine, ascitic and pleural fluid) were studied by preparing three comparable smears. One was air dried for Giemsa stain, one wet fixed in 95% ethanol and one dried on a hot plate at 37 degrees C, rehydrated in normal saline for 30 seconds and fixed in ethanol. The latter two were stained with Papanicolaou stain, and a comparison was made of the (1) retention of red blood cells, (2) retention of epithelial or mesothelial cells, and (3) cytologic preservation. The Giemsa-stained smear was used as a control for (1) and (2). Complete lysis of red blood cells was noted in the rehydration smears as compared with 70% red blood cell retention in the wet-fixed smears (P < .01). The rehydration smears retained 78% urothelial cells as compared with 55% in the wet-fixed smears (P < .01). For ascitic and pleural fluid the cell retention did not differ significantly. The wet-fixed smears scored better for overall cytologic preservation, but the difference was not significant. The rehydration smears showed a decrease in the chromaticity of staining, more flattened cell clusters and slight cell enlargement. The rehydration method was beneficial for urine and blood-stained body cavity fluids.