A simplified approach to diagnostic rectal biopsy in infants and children

Ninety-four patients underwent rectal biopsy with a suction capsule during a two year period. This painless procedure was performed in seventy-one patients for diagnosis of aganglionosis (Hirschsprung's disease). In nine patients, no ganglion cells were encountered, and subsequent surgery confirmed the diagnosis of Hirschsprung's disease in each of these patients. In twenty-three patients, biopsies were taken to search for neuronal storage disease. Six specimens contained abnormal material in the cytoplasm of the ganglion cells.     

CT-guided transthoracic needle biopsy: a comparison between automated biopsy gun and fine needle aspiration

AIMS: We retrospectively investigated the diagnostic accuracy and complication rate of transthoracic core biopsy using an automated biopsy gun and compared the findings with those of aspiration needle biopsy. PATIENTS AND METHODS: Seventy-three patients underwent 74 core biopsy procedures and 50 patients underwent 52 aspiration biopsy procedures. Of these, a final diagnosis was obtained in 107 lesions with surgery or clinical course. Fifteen patients in which a final diagnosis was not obtained were excluded from the study on diagnostic accuracy. Thus, in the study of diagnostic accuracy, 63 core biopsy procedures for 62 lesions are included. Core biopsy was performed with an 18 G cutting needle using an automated biopsy gun. Aspiration biopsy was performed with a 20 G aspiration needle. RESULTS: Core biopsy yielded sufficient material in 57/63 procedures (90.5%). A correct diagnosis was obtained in 36 procedures (85.7%) for malignant leisons and a specific benign diagnosis was obtained in 11 procedures (52.4%). Aspiration biopsy yielded a correct diagnosis in 26 procedures (81.3%) for malignant leisons and in seven (46.7%) for benign lesions. The overall correct diagnosis were 75.8% and 71.7% with core biopsy and aspiration biopsy, respectively. Core biopsy gave a higher predictive rate than that of aspiration biopsy for both benign and malignant lessons (P < 0.02). Pneumothorax occurred in 18/74 (24.3%) patients with core biopsy and in 18/45 (40.0%) patients with aspiration biopsy. Of these, three with core biopsy and two with aspiration biopsy needed tube drainage. The other complication was haemoptysis, which occurred in six patients following core biopsy and in three after aspiration biopsy. All nine cases subsided spontaneously. There were no fatal complications. CONCLUSIONS: Core biopsy with a biopsy gun increase the diagnostic accuracy with a higher histologic predictive rate and no obvious additional risk of complications.     

Blind pleural biopsy using a Tru-cut needle in moderate to large pleural effusion--an experience

BACKGROUND: Pleural biopsy is invaluable for the etiological diagnosis of pleural diseases in the presence of an exudative pleural effusion. Conventionally, pleural biopsy is either performed with the Cope's or the Abrams pleural biopsy needles. A few investigators have used the Tru-cut biopsy needle with or without ultrasound guidance. We report our experience in performing closed pleural biopsy using a Tru-cut needle without ultrasound guidance in moderate to large exudative pleural effusion. We used a perpendicular approach to biopsy the pleura instead of the tangential approach described earlier. METHODS: Closed Tru-cut biopsy was performed in 27 consecutive patients with exudative pleural effusion who volunteered to undergo the procedure. The biopsy specimen was sent for histopathology. Pleural fluid analysis and other relevant investigations required to obtain a specific diagnosis were carried out. RESULTS: A specific diagnosis of tuberculosis was obtained on histopathology of pleural tissue in 12 out of 16 patients (diagnostic yield 75%) and in 5 out of 7 patients with malignancy (diagnostic yield 71%). Among the other 4 patients, other causes of exudative pleural effusion were detected in 3 and in 1 patient, no specific diagnosis could be made, despite extensive investigation. CONCLUSION: Closed pleural biopsy using a Tru-cut needle is effective for the specific diagnosis of exudative pleural effusion. The use of a perpendicular approach to biopsy the pleura does not seem to increase the complication in moderate to large pleural effusion.     

Percutaneous needle aspiration of hilar and mediastinal masses

Needle aspiration biopsy of hilar and mediastinal masses was attempted in 100 patients and completed in 91. There were no major complications. In the group with completed biopsies, there were 83 patients with malignant neoplasms; a positive diagnosis of malignancy was established in 80 (96%). Two of the three false-negative results occurred in patients with Hodgkin disease. In all 8 patients with benign masses, the biopsy results were correct. Five of the nine incomplete biopsies occurred in patients with aortic aneurysms that simulated lung or mediastinal masses. In the other 4 patients, the needle biopsy was not completed for technical reasons. Needle biopsy can be performed in practically all areas of the mediastinum, does not require general anesthesia or hospitalization, and is well tolerated by the patient. In this series, the use of mediastinal needle biopsy made it possible to avoid surgery and mediastinoscopy in 72 patients with unresectable malignant neoplasms and 5 patients with innocuous benign mediastinal masses. Needle biopsy may be the preferred initial procedure to obtain a tissue diagnosis in patients with mediastinal masses.     

The applicability and diagnostic effectiveness of transjugular liver biopsy

BACKGROUND: The aim of this study was to evaluate the applicability, the diagnostic profitability and the incidence of complications associated with tranjugular liver biopsy associated with the measurement of the hepatic venous pressure gradient (HVPG). PATIENTS AND METHODS: The clinical histories of 829 consecutive patients in whom transjugular liver biopsy was performed from 1982 to 1993 were reviewed. The diagnostic value of the sample obtained was evaluated in all the patients and the HVPG determined. Moreover, the size of the greatest fragment obtained during biopsy was also determined. RESULTS: Material for histologic study was obtained in 95% of the cases. In 70% the biopsy was diagnostic, in 11% it provided data contributing to diagnosis and in 19% it was not useful. Potentially severe complications were presented in 0.8% of cases being fatal in one (0.1%). The obtention of a fragment of small size was significantly associated with the presence of disease with marked fibrosis and high HVPG. A HVPG > 10 mmHg in patients with a suspicion of liver disease had a sensibility of 92% and a specificity of 63% for the diagnosis of hepatic cirrhosis. In 83% of patients with a GPVH > 10 mmHg in whom the biopsy was not useful, the diagnosis of hepatic cirrhosis was performed by other methods. CONCLUSIONS: Transjugular biopsy in a safe, effective diagnostic method in patients with severe coagulation disorders. The appearance of the material obtained and the HVPG provide useful information for diagnosis although the biopsy is not diagnostic.     

Leg blood flow during slow head-down tilt with and without leg venous congestion

BACKGROUND AND STUDY AIMS: Endoscopy and biopsy from a suspicious Vater's papilla may establish an early preoperative diagnosis of a periampullary tumor. However, information regarding the diagnostic accuracy of this procedure is limited and variable. The aim of the present study was to evaluate retrospectively the accuracy of this procedure compared to that of other diagnostic methods. PATIENTS AND METHODS: Among 928 patients referred to our institute for endoscopic retrograde cholangiopancreatography (ERCP), a suspicious Vater's papilla was seen in 28. In each case comparison was made between the pre-ERCP clinical diagnosis, endoscopic appearance, histologic interpretation of endoscopic biopsies, and the final diagnosis. Two patients in whom a final diagnosis was not available were excluded from the study. RESULTS: A final diagnosis of an ampullary or periampullary carcinoma was established in 17 patients (65%), a carcinoma within an adenoma of the papilla in three patients (12%), and adenoma and a metastatic gallbladder carcinoma in one patient each. The remaining four patients (15%) were finally diagnosed as having "pseudotumors" (due to choledocholithiasis). Eight (38%) of the 21 patients with ampullary or periampullary neoplasm also had gallstones. A pre-ERCP diagnosis (by clinical evaluation and non-invasive imaging) of tumor versus choledocholithiasis was accurate in only 65% of all 26 patients. In these, the diagnostic accuracy of endoscopic appearance and endoscopic biopsy was 77% and 85%, respectively. Regarding the 21 patients with carcinomas, the diagnosis by endoscopic appearance was more accurate than that by endoscopic biopsy (90% vs 81%). Unlike the positive predictive values, the negative predictive values for malignancy were weak: 33% for the endoscopic appearance and 50% for the endoscopic biopsy. CONCLUSIONS: Because of a high incidence of concurrent cholelithiasis, many patients with a periampullary tumor seen during ERCP are misdiagnosed earlier (by clinical evaluation and non-invasive imaging) as having choledocholithiasis only. However, the accuracy of endoscopy and biopsy is also limited. This limitation must be considered when evaluating the optimal management of patients with suspected periampullary tumor.     

Metastatic seminoma simulating malignant lymphoma in an HIV infected hemophiliac

Although most common, malignant lymphoma and Kaposi's sarcoma are not the only malignancies encountered in lymph nodes from HIV-infected patients. An increased frequency of testicular germ cell tumors in HIV-infected individuals has been reported. We report here the first case, to our knowledge, of a metastatic seminoma in an HIV-infected hemophiliac. The atypical clinical presentation, cervical and axillary adenopathy, simulated malignant lymphoma. The diagnosis was first suspected when a fine needle aspiration biopsy from an enlarged cervical node revealed a mixture of benign appearing lymphocytes and loosely cohesive large tumor cells in a "tigroid" background. Immunocytochemistry and a subsequent excisional biopsy confirmed the cytologic diagnosis. Metastatic germ cell tumors should be considered in the differential diagnosis of HIV-related lymphadenopathy.     

The prevalence of Helicobacter pylori-positive serology in asymptomatic children

Surgeons frequently perform sural nerve biopsy as part of the work-up of patients with peripheral neuropathy. The indications for the procedure, therapeutic value, and complications associated with the procedure have received little attention in the surgical literature. A retrospective chart review of 60 patients with the suspected diagnosis of peripheral neuropathy undergoing sural nerve biopsy was performed. Vasculitis was suspected in 29 (48%) patients undergoing biopsy. This diagnosis was confirmed in 6 of the 29 patients and resulted in the alteration of therapy in 31% of patients with this suspected diagnosis. In 27 (45%) patients, the etiology of their peripheral neuropathy was unknown. Twelve (44%) patients in this group had sural nerve pathology; however, no change in therapy was required. Ten patients in our series had associated malignant tumors; some of these patients were diagnosed after referral for sural nerve biopsy. Twenty-five (42%) patients remained undiagnosed after biopsy. Nerve conduction studies were performed in 14 (22%) patients. Thirteen patients with abnormal lower extremity nerve conduction studies had 6 normal and 7 abnormal biopsy results. The one patient with a normal study had a normal nerve biopsy result. There were six (10%) patients with wound infections, seven (12%) patients with delayed wound healing, and three (5%) patients with new onset of chronic pain in the distribution of the sural nerve, for an overall complication rate of 27%. There was no correlation between the preoperative use of antibiotics, type of local anesthetic used, or length of nerve excised and complication rate. We conclude that the complication rate after sural nerve biopsy is significant. Strict criteria should be employed in selecting patients for sural nerve biopsy including a careful neurologic history and physical examination, nerve conduction studies, appropriate work-up for vasculitis if suspected, and implementation of a search for malignancy if this is not apparent. If the diagnosis is still in question, then sural nerve biopsy would seem appropriate, especially in patients with suspected vasculitis.     

Uveal lymphoid infiltration. Report of four cases and clinicopathologic review

PURPOSE: The purpose of the study was to report the clinicopathologic features of four patients with uveal lymphoid infiltration who were diagnosed by a conjunctival biopsy. DESIGN: A case series. PARTICIPANTS: Four patients at four institutions participated. MEASURES: The histopathologic findings of the conjunctival and episcleral biopsy specimens from four patients with the diagnosis of uveal lymphoid infiltration were recorded. The conjunctival specimens were placed in 10% neutral buffered formaldehyde solution or B5 solution and processed routinely for light microscopic examination and immunohistochemical analysis for B cells and T cells and kappa and lambda light chains. The clinical and histopathologic findings were compared with 47 previously reported cases of uveal lymphoid infiltration. RESULTS: Two men and two women (average age = 57 years) presented with diffuse punctate to coalescent yellow uveal infiltrates and epibulbar pink fleshy lesions. Ultrasonography of the lesions showed diffuse choroidal thickening and a lack of choroidal or scleral excavation. The conjunctival biopsy specimens showed diffuse infiltration of the substantia propria with B lymphocytes with variable kappa and lambda restriction. Scattered T lymphocytes also were present. Plasmacytoid cells and a prominent Grenz zone were present. CONCLUSIONS: Patients with solitary or multiple yellow uveal infiltrates should have careful conjunctival evaluation for the presence of pink conjunctival lesions. Biopsy specimens of the conjunctival lesion may establish the diagnosis of uveal lymphoid infiltration.     

Emergency open lung biopsy

Twenty-eight patients underwent open lung biopsy on an emergency basis. The clinical course in each case was deteriorating rapidly, and all were in respiratory failure. The correct diagnosis was established in 96% of the biopsies (27 of the 28 patients). The clinical diagnosis prior to biopsy was in error or incomplete in 15 (55%) of the patients. Specific therapy was lifesaving in 12 of the 28 patients. The value of the procedure outweighed the complications. Thrombocytopenia and positive end-expiratory pressure ventilation were not contraindications to biopsy.     

The new temperance movement in the United States: what happened to macrostructural factors in alcohol problems?

BACKGROUND: Pulmonary tuberculosis can produce unusual radiographic appearances and negative results of sputum and bronchoscopic examinations are common. This study assessed the value of ultrasound guided aspiration biopsy in the diagnosis of pulmonary tuberculosis with unusual radiographic appearances. METHODS: Thirteen patients, ultimately diagnosed as having tuberculosis, underwent a chest ultrasonographic examination between June 1984 and August 1991. All had sputum available for examination and nine were also examined by bronchoscopy. Ten patients who had a negative sputum smear and negative bronchoscopic brushing smears underwent ultrasound guided aspiration or biopsy. Percutaneous aspiration was performed with a 22 gauge needle. If the smear did not reveal acid fast bacilli, a biopsy sample was taken with a 16 gauge Tru-cut needle to obtain a histological diagnosis. RESULTS: The ultrasonographic examination delineated the more complex nature of the lesions better than the chest radiograph. Ultrasound guided aspiration biopsy provided the diagnosis in nine of 10 patients, while the sputum smear and culture provided diagnosis in five of 13, and bronchoscopy in four of nine. In terms of rapid diagnosis, ultrasound guided aspiration biopsy gave the diagnosis in eight of 10 cases. No patient developed a major complication. CONCLUSION: Ultrasonography can direct the needle to the most suitable part of a lesion to obtain the relevant specimens. The diagnostic yield is high and the procedure is relatively safe. It is especially helpful in patients with negative results of sputum and bronchoscopic examinations.     

Uterine myomata and outcome of assisted reproduction

BACKGROUND: Open lung biopsy (OLB) has long been considered the gold standard for the diagnosis of parenchymal lung disease. With recent advances in computed tomographic imaging and diagnostic techniques (eg, bronchoscopy), we thought it necessary to reevaluate the role of OLB in the management of patients with interstitial lung disease. METHODS: We carried out a retrospective analysis of 103 OLBs performed at Hadassah University Hospital, Jerusalem, and Carmel Medical Center, Haifa, between 1980 and 1994. Data gathered included demographic information, underlying condition, indications for biopsy, diagnosis before biopsy, final diagnosis, change in therapy, and mortality. "Benefit" was defined as a change in therapy resulting in survival. RESULTS: There were 45 immunocompetent patients (group 1), 39 immunocompromised patients (group 2), and 26 children (group 3), 7 of whom were included in group 2 for analysis. Overall, a diagnosis was reached after OLB in 85% of patients. An unexpected diagnosis was reached in 52%, and a change in therapy was instituted in 46%. The overall mortality rate was 20%. In group 1, the mortality rate was 13%, and "benefit" from OLB was reached in only 18%. In group 2, the mortality rate was 39%, and "benefit" was achieved in 46%, and in group 3, the mortality rate was 12% and "benefit", 50%. CONCLUSIONS: Open lung biopsy is an excellent diagnostic technique. In immunocompetent patients, the "benefit" is relatively low, as therapy (corticosteroids) is frequently used after biopsy. In immunocompromised patients, therapy changes substantially after OLB, but mortality is high. Therefore, OLB should be reserved for patients in whom the diagnosis is likely to lead to a change in therapy and in patients in whom the underlying condition has a reasonable prognosis according to the clinical impression by the attending physician.     

Nucleic acid detection as a diagnostic tool in polyomavirus JC induced progressive multifocal leukoencephalopathy

Procedures involved in the diagnosis of JC virus central nervous system infection range from detection of virus specific products in biopsy material to demonstration of viral DNA in cerebrospinal fluid by PCR. Despite the fact that PCR is the most sensitive method for the detection of virus in clinical specimens, diagnostic evaluation is increasingly difficult in view of the possible subclinical activation of persistent JCV infection in the central nervous system of high risk patients. Therefore, PML diagnosis by molecular detection of JCV DNA in biopsy material was compared with diagnosis by PCR on CSF of patients with and without PML. Evaluation of the diagnostic techniques revealed that stereotactic biopsy based PCR diagnosis at present combines speed and sensitivity with the highest specificity available. Although the non invasive technique of JCV detection in CSF by PCR is even more sensitive leading to detection of about 20 genome equivalents per 1 microl of CSF, the specificity of the method is limited by subclinical presence of JCV DNA in CSF of neurologically asymptomatic HIV infected patients. Additionally, autopsy proven PML cases remaining JCV negative in PCR on CSF become a common finding. Therefore, in cases where biopsy is not performed, diagnosis of PML can only be achieved in combination with neurological and radiological diagnosis.     

Fluoroscopically controlled transbronchial biopsy of solitary peripheral pulmonary lesions using the fibreoptic bronchoscope

Experience of fluoroscopically controlled transbronchial biopsy using the fibreoptic bronchoscope in 30 patients with solitary lesions in the peripheral lung fields beyond bronchoscopic vision is described. At the time of submitting this paper for publication (30 January 1978) no account of the technique has been reported in the British literature. In 21 patients with a final diagnosis of bronchial carcinoma a positive biopsy diagnosis was obtained in 14 (67%). Five of seven patients (71%) with a final diagnosis of an inflammatory condition showed evidence of acute or chronic inflammation on biopsy. There were no complications. The procedure is indicated when a definitive diagnosis is required for management planning in clinically inoperable patients, or when a tissue diagnosis is particularly desired in an attempt to obviate the need for thoracotomy. The relative safety makes this the biopsy technique of choice for the evaluation of isolated peripheral pulmonary opacities.     

Diagnosis of prostate carcinoma on biopsy specimens improved by basal-cell-specific anti-cytokeratin antibody (34 beta E12)

The identification of basal cells by the basal-cell-specific anti-cytokeratin antibody 34 beta E12 has been shown to be useful in the diagnosis of prostate carcinoma. To determine the usefulness of 34 beta E12 in prostate biopsies we examined formalin-fixed needle biopsy specimens. In a 17-month period 796 prostate needle biopsies obtained from 293 patients were evaluated on hematoxylin and eosin stains; all 796 biopsy specimens were immunostained as well. Immunostaining with 34 beta E12 reduced the rate of equivocal cases from 5.1% to 1.0% and additionally offered a means of quality assurance by confirming the diagnoses of 61 prostate carcinomas made on the basis of biopsy specimens.     

Together wherever we go: the ethnographic child and the developmentalist

We demonstrated immunohistochemical staining of a-fetoprotein (AFP) in small hepatocellular carcinoma (HCC). Fifty-six patients with HCC less than 2 cm in diameter were studied. Twenty-five HCCs (44.6%) were positive for AFP-staining. The positive rate of AFP-staining in HCC tissue was higher in the patients with serum AFP concentration above 20 ng/ml than that of the patients with below 20 ng/ml. AFP-staining was demonstrated on the rough endoplasmic reticulum of HCC cells by immuno-electron microscopy. AFP-staining of tissue specimens obtained by fine needle biopsy is useful in the histologic diagnosis of HCC.     

Identity in molecular structure between "differentiation enhancing factor" of murine erythroleukemia cells and the 30 kD heparin-binding protein of developing rat brain

Bone marrow involvement by anaplastic large cell anaplastic large cell (ALC) lymphoma can be difficult to detect on routine morphologic examination alone. In a series of 42 patients with ALC lymphoma, the authors analyzed: (1) the usefulness of a limited panel of monoclonal antibodies directed against CD30 (Ber-H2, HRS4) and epithelial marrow involvement on routinely processed biopsy specimens; and (2) the prognostic significance of bone marrow involvement as detected on both morphologic and immunohistochemical grounds. On conventional examination, 17% of the patients were found to have bone marrow involvement at diagnosis. However, after immunohistochemical analysis, occult malignant cells were detected in 23% of the patients with negative bone marrow biopsy on routine histology. The low percentage of positive cases on routine morphologic examination compared to immunohistochemical examination was related to: (1) the scarcity of neoplastic cells which were scattered among hematopoietic cells; (2) the difficulty of distinguishing malignant cells from immature hematopoietic elements; and (3) the absence of alteration of the reticulin network. The authors observed a significant association between marrow infiltration and the presence of hematologic abnormalities (mostly anemia or cytopenias) at diagnosis, both in children and adult patients. More importantly, a significant lower survival was seen in patients with bone marrow involvement compared to those without bone marrow involvement. Immunohistochemistry with anti-CD30 and anti-EMA antibodies should be performed systematically in bone marrow biopsies from patients with ALC lymphoma to reliably identify the presence of bone marrow involvement that appears to carry a poor prognosis.     

Diagnostic laparoscopy and liver disease: experience of 200 cases

BACKGROUND: Laparoscopy is an old technique that is frequently used by gastroenterologists in America and Germany. With modern equipment it is now possible to perform this technique under local anaesthesia. AIM: To evaluate the usefulness and safety of laparoscopic liver biopsy. METHODS: Liver biopsy was routinely performed by laparoscopy under local anaesthetic and sedation. A standard 5 mm laparoscope was used and a pneumoperitoneum induced with nitrous oxide. RESULTS: Two hundred consecutive patients were laparoscoped and underwent liver biopsy. In five patients the liver could not be visualised due to adhesions. Two patients had bleeds related to the procedure. Twenty-five patients had malignancy diagnosed by guided biopsy. Eight of these had been missed by ultrasound prior to laparoscopy. Cirrhosis was diagnosed laparoscopically in 72 patients. Histology was unable to confirm this diagnosis in four patients. CONCLUSION: Laparoscopy can be performed safely and comfortably on patients with local anaesthetic and sedation. The visualisation of the liver can add valuable information to liver biopsy.     

Bone marrow biopsy in the diagnosis of fever of unknown origin in patients with acquired immunodeficiency syndrome

BACKGROUND: Fever is commonly observed in patients with human immunodeficiency virus (HIV) disease and frequently eludes diagnosis. The role of bone marrow biopsy in the diagnosis of fever of unknown origin in patients infected with HIV remains controversial. PATIENTS AND METHODS: One hundred twenty-three consecutive patients with 137 episodes of fever lasting 10 or more days without diagnosis after 1 week of hospitalization were evaluated by bone marrow biopsy. RESULTS: Overall, a specific diagnosis was achieved in 52 episodes by means of culture and histopathological examination (diagnostic yield, 37.9%). Three types of disease were found: mycobacterial infections (n = 36, 69% of documented episodes), including 18 patients with disseminated tuberculosis and 14 with Mycobacterium avium-intracellulare complex infections; non-Hodgkin lymphomas (n = 12, 23%); and visceral leishmaniasis (n = 4, 8%). Although bone marrow cultures were more sensitive than microscopic examination with special stains for the diagnosis of mycobacterial infections, the pathological examination of bone marrow led to a more rapid diagnosis of disease. In addition, the histopathological examination of bone marrow alone led to the diagnosis of a specific condition in 43 episodes (31.3% of all episodes). CONCLUSIONS: Bone marrow biopsy is a useful procedure for the diagnosis of fever in patients with advanced HIV disease, particularly in areas where tuberculosis and leishmaniasis are prevalent. Involvement of the marrow may be the first indication of the existence of extranodal non-Hodgkin lymphoma. For Mycobacterium avium-intracellulare complex infection, blood cultures were more sensitive than bone marrow biopsy.     

The ankle and hindfoot of rheumatoid arthritis patients: study with computerized tomography]

According to the recommendations of the Bethesda System, the diagnosis of atypical squamous cells of undetermined significance (ASCUS) should be further qualified, when possible, as to whether a reactive or a squamous intraepithelial lesion (SIL) is favored. To determine the utility of this recently proposed terminology, we undertook this study to correlate the diagnosis of ASCUS (with or without qualifiers) with results obtained from examination of biopsy specimens. All patients were identified for the study who had a coloposcopically obtained cervical biopsy specimen or endocervical curettage specimen recorded in the surgical pathology files at Beth Israel Hospital, Boston, Massachusetts, from April 1994 through September 1994 and had either prior or concurrent Pap smear(s) reported as ASCUS, ASCUS-favor reactive, ASCUS-favor SIL, or SIL-low grade (SIL-LG). Patients with a cytologic diagnosis of SIL-LG served as a reference group. A total of 435 patients with 485 Pap smears were included. The prevalence rates of biopsy-proven SIL in patients with a cytologic diagnosis of ASCUS-favor reactive, ASCUS, ASCUS-favor SIL, and SIL-LG were 10, 28, 36, and 55%, respectively. The difference between cases diagnosed as ASCUS (with or without qualifiers) and SIL-LG, with respect to the presence of SIL at examination of the biopsy specimen, was statistically significant (P < 0.001 for all correlations). Cases diagnosed as ASCUS-favor reactive had a significantly lower rate of biopsy-proven SIL compared with those diagnosed as ASCUS and ASCUS-favor SIL (P < 0.01 for both correlations). A significant proportion of biopsy specimens with Pap smear diagnosis of ASCUS-favor SIL had SIL-high grade (15%). In contrast, an underlying SIL-high grade is much less likely in patients with ASCUS (unqualified) (3%) or when a reactive process is favored (3%). It seems justified to manage patients with ASCUS-favor SIL in a manner similar to those with SIL-LG. A conservative management seems appropriate for patients with ASCUS and ASCUS-favor reactive.