Mediastinoscopy: a diagnostic procedure in hilar and paratracheal lymphadenopathy

Diagnosis and Detection of Sarcoidosis. An Official American Thoracic Society Clinical Practice Guideline

Background: The diagnosis of sarcoidosis is not standardized but is based on three major criteria: a compatible clinical presentation, finding nonnecrotizing granulomatous inflammation in one or more tissue samples, and the exclusion of alternative causes of granulomatous disease. There are no universally accepted measures to determine if each diagnostic criterion has been satisfied; therefore, the diagnosis of sarcoidosis is never fully secure.

Methods: Systematic reviews and, when appropriate, meta-analyses were performed to summarize the best available evidence. The evidence was appraised using the Grading of Recommendations, Assessment, Development, and Evaluation approach and then discussed by a multidisciplinary panel. Recommendations for or against various diagnostic tests were formulated and graded after the expert panel weighed desirable and undesirable consequences, certainty of estimates, feasibility, and acceptability.

Results: The clinical presentation, histopathology, and exclusion of alternative diagnoses were summarized. On the basis of the available evidence, the expert committee made 1 strong recommendation for baseline serum calcium testing, 13 conditional recommendations, and 1 best practice statement. All evidence was very low quality.

Conclusions: The panel used systematic reviews of the evidence to inform clinical recommendations in favor of or against various diagnostic tests in patients with suspected or known sarcoidosis. The evidence and recommendations should be revisited as new evidence becomes available.

Comparison of biopsy procedures in intrathoracic sarcoidosis

A series of 78 patients, mainly young males, with intrathoracic manifestations of sarcoidosis, found on routine chest X-ray, were examined according to a prescheduled program including different biopsy procedures. In 76% the intrathoracic changes were isolated hilar adenopathy, in 9% isolated pulmonary lesions and in 15% hilar adenopathy plus pulmonary lesions. Lymph nodes containing granulomas were found by mediastinoscopy in 41 of 44 patients and by scalene fat pad biopsy in 20 of 34 patients. In 27 of 76 patients granulomas were found by liver biopsy. Complications to the biopsies were more frequent with mediastinoscopy than with the other two biopsy procedures, but no serious complications occurred. Biopsy through mediastinoscopy is thus preferable in patients of this kind. The necessity of doing biopsies to support the diagnosis of sarcoidosis is discussed on the basis of the literature and our own studies. In younger patients with asymptomatic, bilateral hilar adenopathy without pulmonary lesions it seems justifiable to omit biopsy, whereas biopsy is mandatory in patients with unilateral hilar lymph adenopathy and patients with pulmonary lesions. In all cases the course of the disease should be followed for a rather long period.

Thoracic lymphadenopathy in Asians resident in the United Kingdom: role of mediastinoscopy in initial diagnosis

Although the incidence of superficial glandular tuberculosis is high in Asian immigrants, a clinical diagnosis without biopsy has previously been shown to be inaccurate in 22% of cases. The role of diagnostic mediastinoscopy and biopsy in thoracic lymphadenopathy was therefore evaluated in 41 consecutive Asian patients. Tuberculosis was diagnosed by histological examination or culture (or both) of gland biopsy material in 24 (59%). A further 12 patients, however, also received antituberculous chemotherapy, with a response in 10 cases. If these are included, 34 (83%) were finally considered to have tuberculosis. The symptoms and ages of the patients with tuberculosis were similar to those typically seen in caucasians with sarcoidosis. Six had tuberculous bilateral hilar lymphadenopathy. In only four cases (10%) was a positive diagnosis other than tuberculosis established; in two (lymphoma and thymoma) mediastinoscopy confirmed preoperative suspicions, and saved only two more (with sarcoidosis and vascular anomaly) from unnecessary antituberculous treatment. Complications included severe haemorrhage (1) and chronic tuberculous sinus in the endoscopy tract (2). Mediastinoscopy is unlikely to change management in most patients, produces an appreciable amount of morbidity, and should be reserved for cases in which there is additional clinical doubt. Any future decline in the prevalence of tuberculosis in Asians may, however, require its further evaluation.

Sarcoidosis: histopathological definition and clinical diagnosis

Sarcoidosis is best defined in histopathological terms as 'a disease characterised by the presence in all of several affected organs and tissues of non-caseating epithelioid-cell granulomas, proceeding either to resolution or to conversion into hyaline connective tissue'. Although the defining characteristics are thus histopathological, diagnosis during life depends largely upon clinical, radiological, and immunological findings. The amount of support required from histology varies greatly from case to case. Though histology from one site cannot in itself establish the diagnosis of sarcoidosis, a generalised disease, detailed histological study of biopsy tissue makes an important and often essential contribution. In many instances, complete lack of necrosis, an intact reticulin pattern, and failure to demonstrate infective agents permit an unequivocal statement of compatibility with this diagnosis; however, a compatible clinical picture and absence of evidence of known causes of local granulomatous reactions or of other generalised granulomatous diseases are required for definitive diagnosis. In some, the histological pattern deviates in some particular from the accepted 'typical' pattern; there may be a little necrosis, the follicular pattern of the granuloma may be less than perfect, and exclusion of known infective agents can never be absolute. In such instances, subsequent surveillance, including possible response to treatment, may show a clinical course justifying a diagnosis of sarcoidosis, and necropsy may establish it; but it must be recognised that in a few cases, particularly those in which the clinical evidence of disease is confined to one organ, diagnosis is likely to remain in doubt for long periods. Reports on the histology of the Kveim test should be made without knowledge of clinical findings and in terms of the presence and quality of granulomatous response. A granulomatous reaction to a validated test suspension makes a contribution to diagnosis similar to the finding of granulomas in an additional organ or tissue.

The Kveim test: analysis of results of tests using colindale (K 12) materials

Results of an analysis are presented of the salient clinical, pathological, and Kveim-test data of importance in the diagnostic assessment of 839 patients in whom a Kveim test was made as part of their routine clinical investigation. From these analyses the following significant observations can be made: 1) The age distribution and negative tuberculin results in patients with sarcoidosis were in keeping with the diagnosis of sarcoidosis, whereas for those in whom a diagnosis other than sarcoidosis was made, they were not. 2) The findings of 64% positive tuberculin results in cases of confirmed sarcoidosis of less than 2 yr known duration and only 39% in those of greater than 2 yr duration are closely similar to those found in international Kveim-test studies reported by Siltzbach in 1966 and Hurley and Bartholomeusz in 1971. 3) The use of the material was helpful in confirming a diagnosis of sarcoidosis in patients with extrathoracic lesions, for positive results were obtained in 33% of those with uveitis 40% of those with erythema nodosum only (findings which are in keeping with those of other studies in the United Kingdom, and 60% among 27 patients presenting with lesions in various sites, including 2 with cranial nerve lesions and one with cardiac arrhythmia. 4) We found only 2 positive reactions (less than 1%) among 221 patients in whom a diagnosis other than sarcoidosis was reached. Clearly these findings show that the Kveim test material. Lots 19 and 22, of spleen K 12 exhibited not only a high degree of reactivity and selectivity for sarcoidosis, but also that they were of considerable practical value as an aid to diagnosis. The finding of only 2(0.9%) positive Kveim tests among 221 patients with diseases other than sarcoidosis is of special interest. Of the different diseases that were ultimately diagnosed only 6 patients tested had lymphoma, only 11 had either pulmonary or lymphatic tuberculosis, and only one had Crohn's disease. Although these numbers are small, it is relevant to compare the Kveim-test data of Lots 19 and 22 of K 12 with those of Lot 5 and of Lot 14 of the same spleen. In validation studies Lot 5 yielded the expected proportion of positive reactions at different stages of sarcoidosis and a negligible proportion of positive reactions with active or quiescent pulmonary tuberculosis or among healthy subjects. However, in subsequent studies in special groups of patients, those with Crohn's disease, ulcerative colitis, or lymphatic tuberculosis, a proportion of the Kveim tests performed with these lots were positive. Within the context of the present field study, the results of these analyses confirm that the last lots of K 12 material exhibited a high degree of selectivity for sarcoidosis and that they emphasize again the practical value of the Kveim tests with suspensions that have undergone careful validation.

Further observations on the transmissibility of Crohn's disease

In controlled experiments normal and immunologically deficient CBA mice were inoculated with whole fresh, fresh autoclaved, fresh supernatant, or filtered supernatant (0.2 mu) of whole Crohn's or non-Crohn's homogenate into footpads, intraperitoneally or intravenously. Epithelioid and giant-cell granulomas were present in a substantial proportion the footpads and in bowel or mesenteric lymph nodes of a proportion of given each fresh Crohn's homogenate by any of these routes 15-17 months after inoculation, but were not present in mice given non-Crohn's or autoclaved Crohn's homogenate. Successful passages were achieved following the inoculation of Crohn's mouse tissue homogenates, including passage from mice receiving filtered supernatant (0.2mu) or whole Crohn's homogenate, into footpads or intravenously. The epithelioid- and giant-cell granulomas evolved slowly over a period of many months following the inoculation of Crohn's tissue or passage homogenates and persisted thereafter. The transmissible agent is inactivated when homogenate from Crohn's tissue is autoclaved, can be passaged successfully into footpads or intravenously, and has been shown to pass an 0.2 mu membrane filter. It is therefore presumably viable and must approximate to the size of a virus or be capable of being deformed to pass a filter of such a pore size (0.2mu).

Validation and standardization of Kveim test suspensions prepared from two human sarcoid spleens

Single lots of a Chase-Siltzbach type I Kveim test material from each of two sarcoid spleens and designated lot 5 of spleen K12 and lot 1 of spleen K13 have been validated alongside a single lot (lot 10) of a 'standard' suspension provided by Dr L. E. Siltzbach and prepared identically from the spleen of patient J (SPLEEN J) in New York. Additionally, a half-dilution of lot 5, K12, was included in this comparison. The reactivity of each suspension was assessed among patients with active and inactive sarcoidosis. The selectivity of each suspension for sarcoidosis was assessed similarly by comparison with results in patients with active and quiescent pulmonary parenchymal tuberculosis and in healthy subjects. All patients were closely matched and two Kveim tests were made in each subject according to a prearranged statistical design. The reactivity of the K12, K12 1/2 dilution, and K13 suspensions among patients with active and inactive sarcoidosis was closely similar to that with the 'standard' S10 suspension and in accordance with the expected proportions of reactions in patients at different stages of sarcoidosis. The K12, K13, and 'standard' S10 suspensions yielded a negligible proportion of positive reactions among patients with active and quiescent pulmonary tuberculosis and among healthy subjects: thus, as judged by these tests each suspension showed a high degree of selectivity for sarcoidosis. The results of this validation study are discussed in relation to the results of other studies in which lots 5 and 14 of K12 and early and late batches of a suspension prepared from another sarcoid spleen at the Commonwealth Serum Laboratories designated CSL and provided by Dr T.H. Hurley in Melbourne were employed. Using lot 5 of K12 positive reactions were found in an appreciable proportion of patients with Crohn's disease, ulcerative colitis, and tuberculous lymphadenitis. A closely similar rate of positive reactions was encountered among patients with Crohn's disease following tests with batch 0025 of CSL suspension and with another lot (lot 14) derived from spleen K12. A close concordance of results was obtained with lot 5(K12) and with batch 0042 CSL among patients with ulcerative colitis, but at a lower rate of reactivity. We conclude that positive reactions also occur in some diseases other than sarcoidosis and consider that the difficulties in determining the criteria for an acceptable test suspension become increasingly apparent as additional Kveim tests are made with one particular lot and with seqential lots of material from a 'validated' tissue source.