Perinephric xanthogranulomatosis: CT diagnosis and confirmation by CT-guided percutaneous biopsy.

Xanthogranulomatosis is an idiopathic, rare process in which lipid-laden histiocytes may deposit in various locations in the body, which if systemic is called Erdheim-Chester disease. A rare case of isolated retroperitoneal, bilateral perinephric xanthogranulomatosis is reported. The diagnosis was suspected on cross-sectional imaging and was confirmed by CT-guided percutaneous core biopsy.

The use of fine-needle aspiration biopsy under ultrasound guidance to assess the risk of malignancy in patients with a multinodular goiter.

PURPOSE: Fine-needle aspiration biopsy (FNAB) is a commonly performed procedure used in the evaluation of solitary thyroid nodules, in which the risk of malignancy is approximately 5% in most patients. Recently, the use of ultrasound (US) guidance in FNAB has been shown to enhance the diagnostic efficacy of this procedure. However, the risk of malignancy in thyroid nodules occurring within a multinodular goiter (MNG) has not been completely clarified, nor has the optimal means of investigating such nodules using FNAB. SUBJECTS AND METHODS: We performed a retrospective study of all patients seen over a 4-year period with a MNG that had one or more nodules who underwent FNAB under US guidance. The results from the history and physical examination, thyroid function and antibody tests, radionuclide studies, thyroid sonogram, cytology of aspirated nodules, and surgical pathology were recorded and analyzed. RESULTS: A total of 93 nodules were aspirated in 61 patients with MNG. Adequate material was obtained in 96% of aspirates on the first attempt. Sixty-seven aspirates in 44 patients yielded benign cytology and 22 aspirates in 15 patients yielded suspicious cytology. All patients with suspicious cytology underwent thyroid surgery. Thyroid cancer was found in 5 of these nodules, including 4 cases of papillary cancer and 1 case of Hürthle cell cancer, and 1 additional patient had occult papillary cancer discovered. The overall malignancy rate in thyroid nodules among the patients with MNG was approximately 5%. CONCLUSIONS: FNAB under US guidance is a useful diagnostic modality in the evaluation of thyroid nodules in selected patients with MNG. Because the risk of thyroid malignancy in these nodules is comparable to that which exists in solitary thyroid nodules, the possibility of thyroid malignancy should be considered in all patients with MNG.

Diagnostic significance of papillary structures and intranuclear inclusions in Hurthle-cell neoplasms of the thyroid.

Papillary structures and intranuclear inclusions, features which are not ordinarily associated with Hurthle-cell lesions, are occasionally noted within Hurthle-cell-rich aspirates. The diagnostic significance of these features in this setting, if any, is unknown. The purpose of this study was to determine whether these features are diagnostically useful. Specifically, since fine-needle aspiration cytology cannot distinguish between Hurthle-cell adenoma and carcinoma, we wanted to know whether the presence of either feature might aid in preoperatively assessing the likelihood of carcinoma vs. adenoma. We identified 12 cases in which a diagnosis of Hurthle-cell lesion was made by thyroid fine-needle aspiration biopsy. All cases had subsequent surgery. For every case, all cytology slides were reviewed for the presence or absence of papillary structures and intranuclear inclusions, after which the findings were correlated with the final surgical pathological diagnosis. Seven of the 12 cases had identifiable papillary structures, ranging from cases where papillary structures comprised the predominant architectural pattern to cases where rare papillary structures were found amidst a predominance of sheets and single Hurthle cells. Four of the 12 cases had intranuclear inclusions. In all cases, intranuclear inclusions were uncommon. Of 6 cases that proved to be Hurthle-cell carcinoma, 5 had papillary structures on the antecedent fine-needle aspirate cytology, and 2 had intranuclear inclusions. Of 6 cases that proved to be Hurthle-cell adenoma, 2 had papillary structures, and 2 had intranuclear inclusions. Papillary structures had a sensitivity of 83% for the presence of carcinoma, a specificity of 66%, a positive predictive value of 71%, and a negative predictive value of 80% (P = 0.2). Intranuclear inclusions had a sensitivity of 33%, a specificity of 66%, and positive and negative predictive values of 50%. Papillary structures are more common in Hurthle-cell aspirates than previously recognized. Their presence is not diagnostic of carcinoma, but neither does their absence rule out carcinoma. However, when found, the likelihood of an ultimate diagnosis of Hurthle-cell carcinoma is increased. On the other hand, intranuclear inclusions, when rare, appear to have no diagnostic value.

Utility of cytokeratin 7 and 20 subset analysis as an aid in the identification of primary site of origin of malignancy in cytologic specimens.

This study was undertaken to assess the utility of combined cytokeratin (CK) 7/20 immunoprofile determination in malignant cytologic cell blocks as an aid to the identification of tumor primary site of origin. Fifty-one cases in which CK 7/20 immunocytochemistry was performed as part of the initial workup were retrieved. Their contribution to the final cytologic diagnosis of tumor primary site of origin was analyzed. CK reactivity patterns were 7+/20- (n = 34), 7-/20+ (n = 9), 7-/20- (n = 7), and 7+/20+ (n = 1). The CK 7+/CK 20- immunophenotype was the most common one obtained, and due to its wide expression in a number of common carcinomas, the least informative. The second most common immunophenotype was CK 7-/20+, which is associated with colorectal origin, and as such was very useful when obtained. The CK immunoprofile was more useful in the setting of a prior carcinoma, being a major diagnostic determinant in 13 cases (55%) from group 1 (those with a prior history of malignancy), compared to 8 cases (29%) from group 2 (those with no prior history of malignancy). In the setting of prior carcinoma, the CK immunoprofile is most useful when carcinomas under consideration have different expected immunoprofiles (e.g., CK 7+/CK20- carcinomas, including lung, breast, ovary, endometrium, and others, vs. CK 7-/CK 20+ carcinomas, primarily colorectal). When similar immunoprofiles are obtained, their usefulness is greater if they are immunoprofiles other than the most common 7+/20- pattern. Similarly, in newly diagnosed carcinomas, the CK immunoprofile either helps to narrow the differential diagnosis or points to a specific diagnosis.

Comparison of aspiration, touch and scrape preparations simultaneously obtained from surgically excised specimens. Effect of different methods of smear preparation on interpretive cytologic features.

OBJECTIVE: To determine whether three commonly used methods of obtaining and preparing cells for cytologic evaluation--touch preparation (TP), fine needle aspiration (FNA) and scrape preparation--yield essentially comparable material for evaluation or whether important differences exist between them that may influence interpretation. STUDY DESIGN: FNA, TP and scrape preparations were made simultaneously on surgically excised specimens. Thirty breast, 6 lung and 12 colon lesions were studied. Each slide was assessed for qualitative and quantitative features. Cellularity was semiquantitatively scored. RESULTS: Scrape preparations were the most cellular (P < .0001). Scrape and TPs often had larger tissue fragments than FNA. However, fragmentation of epithelial groups into smaller clusters and single cells was often noted on scrape preparations. FNAs tended to have cleaner backgrounds than the other two methods. CONCLUSION: Most often, there are few differences between smears prepared by the three techniques studied. However, scrape preparations may yield smears with smaller clusters and single cells as compared to the other two methods; that is a potential source of diagnostic confusion, particularly with respect to benign breast lesions. Scrape preparations uniformly yield more cellular smears. To the extent that cellularity is an interpretive factor in assessing cytologic specimens, it is important to be aware of the increased cellularity of scrape preparations as compared to the other two techniques.

Correlation of cytologic and histologic findings in fibrosing thyroiditis. A case report.

BACKGROUND: Fibrous thyroiditis is the rarest form of thyroiditis. Consequently, needle aspiration biopsy experience is limited. Aspirates generally yield paucicellular smears with, at the most, only occasional, small fragments of connective tissue. CASE: A 35-year-old man presented with a firm right thyroid mass. Aspiration yielded cellular smears with round and irregularly shaped, cellular aggregates. Coarse cytoplasmic granules and intranuclear inclusions were also noted. The lesion was surgically excised, and pathologic examination was consistent with fibrous thyroiditis. CONCLUSION: As confirmed by histopathologic examination, the aspirated atypical cellular aggregates represented thyroid follicular units that were distorted by entrapment within fibrous tissue. Fibrosing thyroiditis may yield an atypical smear pattern.

Fine-needle aspiration as the initial diagnostic modality in malignant lung disease.

Cytologic detection of lung cancer is accepted, accurate, and time-honored. Typically, cytologic workup of a radiologic abnormality proceeds sequentially from sputum to bronchoalveolar cytology, and, if necessary, to fine-needle aspiration biopsy (FNA). Initial use of FNA in lung cancer diagnosis is controversial, but increasingly popular. We therefore decided to objectively assess current practice in cytologic lung cancer diagnosis at our institution. All pulmonary cytologic diagnoses for 1993 and the first half of 1994 were retrieved. Positive diagnoses were then used to access all patient data. Patients were stratified according to the specimen from which the first positive diagnosis was obtained. Of 542 pulmonary cytology specimens, 15% were sputa, 65% were bronchoalveolar, and 20% were FNAs. One hundred sixty-one of 172 malignant diagnoses were first diagnoses. Three percent of first malignant diagnoses were made from sputa, 47% were from lavages, and 50% were from FNAs. Although FNAs comprised just 20% of all pulmonary cytologies, 50% of all new malignant cytologic diagnoses were made by FNA. Initial use of FNA is successful, has a high diagnostic yield and low complication rate, and offers the most direct approach to diagnosis.

Neuroendocrine differentiation in gastric adenocarcinomas. An immunohistochemical study.

BACKGROUND: The stomach contains a wide variety of neuroendocrine cells. Early studies with argyrophilic stains documented the presence of these cells in gastric adenocarcinomas. Immunohistochemical techniques for demonstrating hormones are more sensitive and specific and have been applied only sporadically to gastric adenocarcinomas. Thus, the true incidence of neuroendocrine cells in gastric adenocarcinomas is questionable. METHODS: Formalin-fixed, paraffin-embedded archival tissue specimens from 48 gastric adenocarcinomas were immunostained with antibodies to chromogranin A, synaptophysin, serotonin, gastrin, and neuron-specific enolase. The percentage of cells staining positively was evaluated semiquantitatively. RESULTS: Among 48 gastric adenocarcinomas, 36 (75%) stained positively for chromogranin A, 33 (69%) stained for synaptophysin, 29 (60%) stained for neuron-specific enolase, 17 (36%) stained for gastrin, and 15 (31%) stained for serotonin. The distribution of positivity was highest for chromogranin A (7 cases positive in 26% to 75% of cells) and lowest for serotonin (14 out of 15 cases stained in fewer than 1% of the cells present). CONCLUSIONS: Immunohistochemical evaluation of neuroendocrine markers in gastric adenocarcinomas indicates that a high percentage of tumors contain widely scattered single cells with neuroendocrine differentiation. Most often, however, such cells constitute only a small percentage of the total number of tumor cells present.

Neuroanatomy of the external urethral sphincter: implications for urinary continence preservation during radical prostate surgery.

Post-prostatectomy urinary incontinence probably is multifactorial and sphincteric nerve injury could be a contributing cause. Controversy still exists regarding the innervation of the external sphincter, and currently pudendal nerve injury is not believed to be an etiological factor in post-prostatectomy urinary incontinence. To understand better the sphincter and its innervation, we undertook an anatomical and histological study of 18 adult male cadavers, which revealed that the external urethral sphincter receives part of its innervation through special branches originating from the dorsal nerve of the penis after it splits from the pudendal nerve. These nerve branches were located 0.3 to 1.3 cm. from the prostatic apex, and in 50% of the cadavers they were identified only unilaterally or had only 1 branch on each side. The proximity of these nerves to the prostatic apex may make them liable to injury during radical prostatectomy. These nerves are most likely sensory in nature although the presence of motor components cannot be completely ruled out. Injury to these nerves may explain several features of post-prostatectomy urinary incontinence.

Ploidy status correlates with outcome in stage B prostate adenocarcinoma.

1. While there are extensive data showing that aneuploidy is associated with adverse outcome in stage D prostate cancer, the utility of ploidy analysis in stage B disease is unclear. We determined ploidy in radical prostatectomy specimens from 28 patients with clinical stage B prostate cancer, and with a mean follow-up of 4.1 years (2-10 years). Patients who had no recurrences had a minimum 5 years of follow-up. Patients who had only 2 years of follow-up were included if they had developed bone metastases during this period. 2. Ploidy determinations were done on Feulgen-stained 5-microns paraffin-embedded sections using a CAS 200 image analyzer. At least 400 tumor cells were counted in every case. Tumors with at least 70% diploid cells were classified as diploid, while those with less than 70% diploid cells were classified as aneuploid. The mean percentage of diploid cells in tumors classified as diploid was 90.6 +/- 7.4, while the mean percentage of diploid cells in tumors classified as aneuploid was 36 +/- 21.9. 3. Ploidy status correlated with disease progression: seven of the 10 patients (70%) with disease recurrence had aneuploid tumors, while 13 of 18 patients (72%) who remained disease-free had diploid tumors (P = 0.03, Chi-square test). 4. These data show that patients with stage B disease with aneuploid tumors at the time of prostatectomy are more likely to have recurrent disease within a mean of 3 years (2-6 years) compared to patients with diploid tumors.(ABSTRACT TRUNCATED AT 250 WORDS)

Ploidy status correlates with outcome in stage B prostate adenocarcinoma

1. While there are extensive data showing that aneuploidy is associated with adverse outcome in stage D prostate cancer, the utility of ploidy analysis in stage B disease in unclear. We determined ploidy in radical prostatectomy specimens from 28 patients with clinical stage B prostate cancer, and with a mean follow-up of 4.1 years (2-10 years). Patients who had no recurrences had a minimum 5 years of follow-up. Patients who had only 2 years of follow-up were included if they had developed bone metastases during this period. 2. Ploidy determinations were done on Feugen-stained 5-µm paraffin-embedded sections using a CAS 200 image analyzer. At least 400 tumor cells were counted in every case. Tumors with at least 70 percent diploid cells were classified as diploid, while those with less than 70 percent diploid cells were classified as aneuploid. The mean percentage of diploid cells in tumors classified as diploid was 90.6 ñ 7.4, while the mean percentage of diploid cells in tumors classified as aneuploid was 36 ñ 21.9. 3. Ploidy status correlated with disease progression: seven of the 10 patients (70 percent) with disease recurrence had aneuploid tumors, while 13 of 18 patients (72 percent) who remained disease-free had diploid tumors (P= 0.03, Chi-square test). 4. These data show that patients with stage B disease with aneuploid tumors at the time of prostatectomy are more likely to have recurrent disease within a mean of 3 years (2-6 years) compared to patients with diploid tumors. Ploidy determination done at the time of surgery may offer useful prognostic information

HLA expression by benign and malignant prostatic epithelium: augmentation by interferon-gamma.

Chronic prostatitis is a poorly understood entity that is characterized by lymphocytic infiltration of benign prostatic epithelium. Previously, we and others have shown that prostatic epithelium involved by prostatitis is phenotypically different from uninvolved epithelium. In addition, we have shown that malignant prostatic epithelium is rarely, if ever, infiltrated by lymphocytes. We now report that benign prostatic epithelium expresses HLA-DR only in the presence of lymphocytic inflammation, and that benign epithelium without chronic prostatitis and malignant prostatic epithelium do not express HLA-DR. In order to determine whether HLA-DR expression is inducible on malignant prostatic epithelium and therefore, at least theoretically, susceptible to immune regulation, we studied the DU-145 cell line in culture under various conditions. DU-145 cells did not express HLA-DR under routine culture conditions. However, the addition of interferon-gamma (100 to 6000 U/ml.) resulted in HLA-DR expression by DU-145 cells at 24 hours with maximal expression by 72 hours. In contrast, other cytokines (tumor necrosis factor, interleukin-1, interleukin-2) had no effect on HLA-DR expression. These investigations show that interferon-gamma induces HLA-DR expression on the DU-145 prostatic adenocarcinoma cell line, raising the theoretical possibility that malignant prostatic cells may be induced in vivo to express HLA-DR and thus become susceptible to immune regulation.

Tumor angiogenesis correlates with metastasis in invasive prostate carcinoma.

Tumor growth and metastasis require angiogenesis; and microvessel density, a measure of tumor angiogenesis, correlates with metastasis in breast and lung carcinoma. To determine how microvessel density correlated with metastasis in prostate carcinoma, we counted microvessels within the initial invasive carcinomas of 74 patients (29 with metastasis, 45 without). Microvessels were highlighted by immunostaining endothelial cells for factor VIII-related antigen. Without knowledge of the patient's cancer stage, microvessels were counted in a 200 field (0.739 mm2) in the most active areas of neovascularization. The mean microvessel count in tumors from patients with metastases was 76.8 microvessels per 200 field (median, 66; standard deviation, 44.6). The counts within carcinomas from patients without metastasis were significantly lower, 39.2 (median, 36; standard deviation, 18.6) (P < 0.0001). Microvessel counts increased with increasing Gleason's score (P < 0.0001), but this increase was present predominantly in the poorly differentiated tumors. Although Gleason's score also correlated with metastasis (P = 0.01), multivariate analysis showed that Gleason's score added no additional information to that provided by microvessel count alone. Assay of microvessel density within invasive tumors may prove valuable in selecting patients for aggressive adjuvant therapies in early prostate carcinoma.

The challenge of Pneumocystis carinii culture.

Published and unpublished data on the cultivation of P. carinii were reviewed by a panel of investigators convened by the National Institutes of Health. Although several cell culture systems allow propagation of P. carinii for a limited time with modest rates of replication, these have not proved adequate for isolation of P. carinii in sufficient quantity to explore important basic biological investigation. Attempts at cell-free culture have yielded only transient proliferation. Because much of the unsuccessful work on cultivation of the organism has been unpublished, the panel agreed that these data may be useful to other investigators in designing experimental strategies for cultivation. Therefore, the purpose of this report is to make available this information to researchers, lest others unknowingly repeat unsuccessful methods. It is hoped that by documenting the history and the complexities of Pneumocystis culture, renewed interest and efforts will be directed toward this fundamental scientific challenge.

Fine needle aspiration of abdominal fat for the diagnosis of amyloidosis.

Amyloidosis is a dysproteinemia characterized by extracellular deposition of amyloid fibrils. Its diagnosis depends on the demonstration of the characteristic apple-green birefringence in tissue stained with Congo red. Aspiration of subcutaneous fat as a means of procuring tissue has received attention in the internal medicine literature. However, this application of fine needle aspiration biopsy has not been investigated extensively by cytopathologists. We therefore report our experience. Over the past two years we performed 18 aspirations of subcutaneous fat on 17 patients in whom amyloidosis was clinically suspected. Eight aspirates were positive for amyloid, and nine were negative. There were no known false-negative results. False positives were more problematic, occurred early in our experience and were due to overinterpretation of occasional long, slender, green strands representing collagen. The true positives were all characterized by large numbers of short, apple-green strands intimately associated with the fat, oriented in multiple directions and occurring in much, if not all, of the aspirated fat. Attention to details of the aspirated material other than the presence or absence of apple-green birefringence can lead to a correct distinction between amyloid and collagen. We conclude that abdominal fat pad aspiration is useful in the workup of suspected amyloidosis, especially since it is a safe, easily performed procedure.

Incidental lymphocytic prostatitis. Selective involvement with nonmalignant glands.

We documented the presence of lymphocytic prostatitis in all prostate specimens received over a 4-month period. Lymphocytic prostatitis was present in 44% of biopsy specimens (n = 77), 95% of transurethral prostatic resection specimens (n = 20), and 100% of total prostatectomy specimens (n = 9). The patchiness of the prostatitis within the prostate in part explains the lower prevalence in the biopsy specimens, which sample a much smaller portion of the gland compared with the other procedures. Lymphocytic prostatitis was seen in prostates both with and without adenocarcinoma. However, in specimens containing carcinoma, the lymphocytic aggregates rarely involved malignant glands. Instead, the aggregates were either stromal or involved nonmalignant glands either adjacent to or away from the tumor, including glands with hyperplasia, atrophy, and prostatic intraepithelial neoplasia. Even when malignant and nonmalignant glands were in close proximity, there was a sharp demarcation with respect to lymphocytic inflammation. Immunohistochemical staining with B-cell and T-cell markers disclosed that the vast majority are T lymphocytes. The localization of lymphoid aggregates to nonmalignant (including prostatic intraepithelial neoplasia) glands but not frankly neoplastic glands, suggests a selective escape of immune detection by neoplastic glands.

Metastasis-associated alterations in phospholipids and fatty acids of human prostatic adenocarcinoma cell lines.

Metastatic variants of human prostatic adenocarcinoma cell lines (DU-145, LNCaP, and ND-1) were studied by using soft agar colony forming efficiency, nude mice tumorigenicity, in vitro invasion assay, and type IV collagenase assay. The DU-145 and ND-1 cell line showed higher metastatic potential than LNCaP. Lipids from DU-145, ND-1, and LNCaP cells were extracted and analyzed by thin-layer chromatography and gas-liquid chromatography. The major lipids were phosphatidylcholine, phosphatidylethanolamine, sphingomyelin, fatty acids, and cholesterol. The sphingomyelin level was significantly higher in highly metastatic cells (DU-145 and ND-1) compared with the lower metastatic variant (LNCaP). The increase in the synthetic pathway and decrease in degradation pathway of sphingomyelin in microsomal fractions was sufficient to account for the measured increase in sphingomyelin in DU-145 cells compared with LNCaP cells. The major fatty acids of these lipids were palmitic (16:0), stearic (18:0), oelic (18:1), and arachidonic acid (20:4). The arachidonic acid level was significantly decreased in DU-145 and ND-1 compared with LNCaP cells. Electron microscopic studies showed no significant changes in the morphology of DU-145, ND-1, and LNCaP cells. The results of these investigations demonstrate for the first time that sphingomyelin and arachidonic acid contents are different in high and low metastatic variants of human prostatic adenocarcinoma cell lines.

Correlation of Pneumocystis carinii cyst density with mortality in patients with acquired immunodeficiency syndrome and pneumocystis pneumonia.

Fifteen percent to 20% of patients with the acquired immunodeficiency syndrome and pneumocystis pneumonia do poorly despite early intervention. It is not known what distinguishes those who die, despite early intervention and aggressive therapy, from those who readily respond to therapy. We used image analysis to determine the relative abundance of cysts within aggregates of Pneumocystis carinii found in induced sputa (21 patients) and bronchoalveolar lavage fluid (14 patients) from 35 patients with pneumocystis pneumonia. We calculated a cyst density (number of cysts per area of aggregate) for each aggregate and a mean cyst density for all of the aggregates on the smear. Six patients died within 2 weeks of diagnosis; four of these six patients who had autopsies all had residual P carinii. The mean cyst density for those who died was 9.7 +/- 3.9 (range, 5 to 15 x 10(-3)). The 29 patients who survived beyond 2 weeks had a mean cyst density of 18.4 +/- 8.7 (range, 5 to 35 x 10(-3); P = .01). Mean cyst density was not influenced by the number of aggregates present in the smear, the variation in cyst density among aggregates in a smear, or the episode of pneumocystis pneumonia. Cyst density determinations alone should not be used to predict outcome for individuals with P carinii pneumonia until further study is completed. Nevertheless, the current study suggests that a low cyst density specimen, which may indirectly indicate a greater proportion of trophozoites compared with a high cyst density specimen, may be associated with an unfavorable outcome in acquired immunodeficiency syndrome-associated pneumocystis pneumonia.

Detection of antibodies to Pneumocystis carinii in bronchoalveolar lavage fluid by immunoreactivity to Pneumocystis carinii within alveoli, granulomas, and disseminated sites.

Although Pneumocystis carinii pneumonia (PCP) is the most common major opportunistic infection in the acquired immunodeficiency syndrome (AIDS), its immunopathogenesis is not fully understood. It is known that anti-pneumocystis antibodies are present in the sera of individuals with and without PCP. In order to determine whether anti-pneumocystis antibodies are also present in bronchoalveolar lavage fluid (BAL), we looked for them, by immunoreactivity with tissue sections of intra-alveolar P. carinii, in the BAL of (a) HIV-seropositive patients with PCP (n = 18); (b) HIV-seropositive patients without PCP (n = 11); and (c) HIV-seronegative patients with nonpneumocystis lung disease (n = 5). BALs from 19 of 29 HIV-seropositive patients were deficient in at least one isotype (13 with PCP, six without PCP), while only one of five HIV-seronegative patients was deficient. Despite the considerable documentation of atypical presentations of disease caused by P. carinii, little is known concerning the mechanisms involved. To determine whether there is any relationship between BAL anti-pneumocystis antibodies and diverse host responses, we studied antibody binding to P. carinii in different settings. IgG antibodies in BAL bound P. carinii within spleen, liver, skin, and muscle, as well as within pulmonary alveoli and granulomas. However, IgA antibodies in BAL bound intraalveolar and disseminated P. carinii but did not bind to P. carinii within pulmonary granulomas.(ABSTRACT TRUNCATED AT 250 WORDS)

Correlation of morphologic diagnosis of Pneumocystis carinii with the presence of pneumocystis DNA amplified by the polymerase chain reaction.

We compared the presence of P. carinii in clinical specimens as detected by standard cytomorphologic techniques with amplification of P. carinii-specific DNA by the polymerase chain reaction (PCR). Results correlated in 33 of 37 instances (89%): nine specimens were positive by both PCR and morphology; 24 specimens were negative by both techniques. Two specimens from one patient were obtained 3 days apart. The first specimen was both cytologically and PCR negative, while the second specimen was both cytologically and PCR positive for P. carinii. At least in some instances, therefore, PCR is no more sensitive than morphology, and other factors such as specimen adequacy are more important. Twelve of the 24 negative specimens were from patients with prior histories of P. carinii pneumonia, suggesting that recurrent disease may be from reacquisition of organisms in previously exposed individuals, rather than reactivation of latent organisms. Discrepant results included three morphologically negative specimens that were positive by PCR. It remains to be determined whether the increased sensitivity of PCR in these cases is real or artifactual. One morphologically positive specimen was negative by PCR. Polymerase chain reaction correlates well with cytomorphologic diagnosis of P. carinii pneumonia and may be a valuable diagnostic and epidemiologic tool.