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Conjunctival Biopsy in Sarcoidosis: Reply
Vol. 100, No.2
Correspondence
Reference 1. Nichols, C. W., Eagle, R. c., Yanoff, M., and Manocal, N. G.: Conjunctival biopsy as an aid in the evaluation of the patient with sarcoidosis. Ophthalmology 87:287, 1980.
_ _ _ _ _ _ _ Reply EDITOR:
_
We agree that conjunctival biopsy is not a useful test for all patients with sarcoidosis, but then few tests in medicine are diagnostic in all patients with a given disease. To quote from the excellent review of diagnostic tests and procedures by Griner and associates;' "The decision to do a given test or procedure is made on the assumption that the results will appreciably reduce the uncertainty relating to a given question." In our study, the uncertainty relating to diagnosis of sarcoidosis was calculated to be reduced 28% (incidence of positive conjunctival biopsy specimens) in patients with suspected sarcoidosis. Griner and associates also stated that, "The physician must decide what level of uncertainty warrants further study before therapeutic decisions can be made." The usefulness of our study is that the histopathologic confirmation of the disease is accomplished in approximately 28% of the patients, ending the "uncertainty" and the need for "further studies." In our opinion, this is important even if the incidence is less than 28%, because it spares many patients from other high-risk and high-cost invasive techniques "before therapeutic decisions can be made." We agree with Dr. Argus that false-negative results do not rule out sarcoidosis, but positive results are certainly useful. The other question raised by Dr. Argus is the practicality of the biopsy of a "suspicious" skin lesion as opposed to a random conjunctival biopsy. The biopsy of a "suspicious" skin lesion in a patient with questionable sarcoidosis shows a higher yield of histologic confirmation, but it represents a purposeful biopsy of a specific lesion and cannot be compared with random conjunctival biopsy done in the absence of "suspicious" lesions. Only the yield of randomly done skin biopsies without suspicious lesions can be compared to the randomly done conjunctival biopsies in our series.
347
Although clinical suspicion of sarcoidosis leads to further examination of the patient, the importance of the "strength of the initial clinical suspicion" is not clear, particularly in ocular disease. In our series, only four patients in Group 1 and three patients in Group 2 had clinical ocular findings consistent with sarcoidosis. Further, in eight cases the positive biopsy specimen diagnosis was based on extremely small «0.25 mm in diameter) granulomas that did not affect the overlying epithelium in any clinically observed way. Therefore, in our opinion, it is difficult to establish a clinicopathologic correlation to warrant the statement by Dr. Argus that "as the clinical suspicion approaches zero, so does the percentage of positive specimens."
ZEYNEL A. KARCIOGLU, M.D. RUSSELL BREAR, M.D.
New Orleans, Louisiana
Reference 1. Griner, P. F., Mayewski, R. J., Mushlin, A. 1., and Greenland, P.: Selection and interpretation of diagnostic tests and procedures. Ann. Intern. Med. 94:553, 1981.
Conjunctival Biopsy in Sarcoidosis EDITOR:
In the article, "Conjunctival biopsy in sarcoidosis" (Am. J, Ophthalmol. 99:68, Jan. 1985), Z. A. Karcioglu and R. Brear reconfirmed and extended the results of Nichols and associates,' suggesting that the chances of obtaining positive conjunctival biopsy specimens in sarcoidosis (that is, containing noncaseating epithelioid cell granulomas) is related to the volume of conjunctiva examined. According to the data presented, using conventional histologic techniques, they were able not only to distinguish between nonspecific follicular reactions and sarcoid lesions but also to assess the activity of the lesions. Reviewing the literature, they lament that the data on positive conjunctival biopsy specimens in sarcoidosis are confusing and the differences between study designs make the results difficult to compare. However, they did not indicate the race of their patients, a key
Correspondence
Reference 1. Nichols, C. W., Eagle, R. c., Yanoff, M., and Manocal, N. G.: Conjunctival biopsy as an aid in the evaluation of the patient with sarcoidosis. Ophthalmology 87:287, 1980.
_ _ _ _ _ _ _ Reply EDITOR:
_
We agree that conjunctival biopsy is not a useful test for all patients with sarcoidosis, but then few tests in medicine are diagnostic in all patients with a given disease. To quote from the excellent review of diagnostic tests and procedures by Griner and associates;' "The decision to do a given test or procedure is made on the assumption that the results will appreciably reduce the uncertainty relating to a given question." In our study, the uncertainty relating to diagnosis of sarcoidosis was calculated to be reduced 28% (incidence of positive conjunctival biopsy specimens) in patients with suspected sarcoidosis. Griner and associates also stated that, "The physician must decide what level of uncertainty warrants further study before therapeutic decisions can be made." The usefulness of our study is that the histopathologic confirmation of the disease is accomplished in approximately 28% of the patients, ending the "uncertainty" and the need for "further studies." In our opinion, this is important even if the incidence is less than 28%, because it spares many patients from other high-risk and high-cost invasive techniques "before therapeutic decisions can be made." We agree with Dr. Argus that false-negative results do not rule out sarcoidosis, but positive results are certainly useful. The other question raised by Dr. Argus is the practicality of the biopsy of a "suspicious" skin lesion as opposed to a random conjunctival biopsy. The biopsy of a "suspicious" skin lesion in a patient with questionable sarcoidosis shows a higher yield of histologic confirmation, but it represents a purposeful biopsy of a specific lesion and cannot be compared with random conjunctival biopsy done in the absence of "suspicious" lesions. Only the yield of randomly done skin biopsies without suspicious lesions can be compared to the randomly done conjunctival biopsies in our series.
347
Although clinical suspicion of sarcoidosis leads to further examination of the patient, the importance of the "strength of the initial clinical suspicion" is not clear, particularly in ocular disease. In our series, only four patients in Group 1 and three patients in Group 2 had clinical ocular findings consistent with sarcoidosis. Further, in eight cases the positive biopsy specimen diagnosis was based on extremely small «0.25 mm in diameter) granulomas that did not affect the overlying epithelium in any clinically observed way. Therefore, in our opinion, it is difficult to establish a clinicopathologic correlation to warrant the statement by Dr. Argus that "as the clinical suspicion approaches zero, so does the percentage of positive specimens."
ZEYNEL A. KARCIOGLU, M.D. RUSSELL BREAR, M.D.
New Orleans, Louisiana
Reference 1. Griner, P. F., Mayewski, R. J., Mushlin, A. 1., and Greenland, P.: Selection and interpretation of diagnostic tests and procedures. Ann. Intern. Med. 94:553, 1981.
Conjunctival Biopsy in Sarcoidosis EDITOR:
In the article, "Conjunctival biopsy in sarcoidosis" (Am. J, Ophthalmol. 99:68, Jan. 1985), Z. A. Karcioglu and R. Brear reconfirmed and extended the results of Nichols and associates,' suggesting that the chances of obtaining positive conjunctival biopsy specimens in sarcoidosis (that is, containing noncaseating epithelioid cell granulomas) is related to the volume of conjunctiva examined. According to the data presented, using conventional histologic techniques, they were able not only to distinguish between nonspecific follicular reactions and sarcoid lesions but also to assess the activity of the lesions. Reviewing the literature, they lament that the data on positive conjunctival biopsy specimens in sarcoidosis are confusing and the differences between study designs make the results difficult to compare. However, they did not indicate the race of their patients, a key