Correspondence

Case 36-2008: A Man with Chronic Daily Headache

N Engl J Med 2009; 360:1153-1155March 12, 2009

Article

To the Editor:

In the discussion of the Case Record of a man with chronic daily headache, by Brass et al. (Nov. 20 issue),1 the thrombocytosis in this patient with giant-cell arteritis should have been noted.2 A platelet count of approximately 430,000 was present 2 to 3 months before admission, and it rose to 670,000 on the second hospital day. The presence of an elevated erythrocyte sedimentation rate, an elevated C-reactive protein level, and an elevated platelet count in the right clinical setting would also have strongly suggested giant-cell arteritis.

Francis J. Mwaisela, M.D.
St. Joseph Medical Center, Towson, MD 21204

2 References

1. 1

   Case Records of the Massachusetts General Hospital (Case 36-2008). N Engl J Med 2008;359:2267-2278
   Full Text | Web of Science | Medline

2. 2

   Lincoff NS, Erlich PD, Brass LS. Thrombocytosis in temporal arteritis rising platelet counts: a red flag for giant cell arteritis. J Neuroophthalmol 2000;20:67-72
   CrossRef | Web of Science | Medline

To the Editor:

Brass et al. discuss the case of a patient with giant-cell arteritis in whom the initial temporal-artery biopsy was negative and in whom the diagnosis was later established by means of contralateral biopsy. The discussants suggest performing bilateral temporal-artery biopsies, stating that “unilateral biopsy leads to underdiagnosis in 20 to 40% of cases.”

However, we wonder whether the references Brass et al. cite support this statement,1,2 given that other studies report that performing a bilateral simultaneous or sequential temporal-artery biopsy when the biopsy of the first side is negative improves the diagnostic yield in about 1 to 5% of cases.1-3 In a review of more than 2500 temporal-artery biopsies performed at the Mayo Clinic over a 10-year period, a contralateral biopsy was positive in 7.4% of cases in which the previous biopsy was negative.4

We suggest that in patients with suspected giant-cell arteritis, if frozen sections are available and the biopsy of the first site is negative, contralateral biopsy should be performed. If bilateral biopsy is performed routinely, one should recognize that the improvement in the diagnostic yield of bilateral biopsies may be lower than that cited by Brass et al.

Kenneth J. Warrington, M.D.
Eric L. Matteson, M.D., M.P.H.
Mayo Clinic, Rochester, MN 55905

4 References

1. 1

   Boyev LR, Miller NR, Green WR. Efficacy of unilateral versus bilateral temporal artery biopsies for the diagnosis of giant cell arteritis. Am J Ophthalmol 1999;128:211-215
   CrossRef | Web of Science | Medline

2. 2

   Pless M, Rizzo JF III, Lamkin JC, Lessell S. Concordance of bilateral temporal artery biopsy in giant cell arteritis. J Neuroophthalmol 2000;20:216-218
   CrossRef | Web of Science | Medline

3. 3

   Danesh-Meyer HV, Savino PJ, Eagle RC Jr, Kubis KC, Sergott RC. Low diagnostic yield with second biopsies in suspected giant cell arteritis. J Neuroophthalmol 2000;20:213-215
   CrossRef | Web of Science | Medline

4. 4

   Calamia KT, Matteson EL, Mazlumzadeh M, Michet CJ, Mertz LE, Hunder GG. Trends in the use of temporal artery biopsy for the diagnosis of giant cell arteritis (GCA): experience in 2539 patients at 3 centers over 11 years. Arthritis Rheum 2005;52:Suppl:S221-S221
   Web of Science

Author/Editor Response

We agree with Mwaisela's statement that the patient's rising platelet count in the months before diagnosis was consistent with giant-cell arteritis. However, to imply that a platelet count of 670,000 strongly suggests giant-cell arteritis overstates the diagnostic value of thrombocytosis. Platelets are acute-phase reactants. Giant-cell arteritis often causes thrombocytosis to the degree reflected by the patient's platelet count, but so do a host of other infectious, malignant, or idiopathic inflammatory conditions. For example, Wegener's granulomatosis, the major alternative diagnosis in this case, often causes thrombocytosis of this magnitude.

Warrington and Matteson suggest that our statement that “unilateral biopsy leads to underdiagnosis in 20 to 40% of cases” is not correct. In fact, the range supported by the studies we cite is 10 to 20%.1,2 In those retrospective studies of patients undergoing bilateral temporal-artery biopsy, unilateral involvement by giant-cell arteritis accounted for 20 to 40% of the cases that were positive for giant-cell arteritis. Assuming that the surgeon had an equal chance of selecting the wrong side for biopsy, then between 10 and 20% of the biopsy-proven cases would have been missed by unilateral procedures.

In the review of biopsies at the Mayo Clinic cited by Warrington and Matteson, 50% of the patients studied underwent unilateral biopsies and 50% underwent bilateral biopsies. In the latter group, among the patients in whom the initial biopsy on one side was negative, 7.4% had positive findings on a subsequent contralateral biopsy. Since overall, 27% of the patients in that study had positive biopsies, this would again indicate that 10 to 20% of the positive cases had been missed on the initial unilateral biopsy.

We believe that a risk of missing the correct diagnosis that ranges from 10 to 20% is too high to be ignored, considering the potential consequences of a missed diagnosis. We strongly encourage the routine performance of bilateral temporal-artery biopsies.

With regard to the use of frozen sections to determine the need for a contralateral biopsy, the usefulness varies considerably across institutions. In some settings, a frozen section can be useful. However, the preparation of frozen sections also consumes substantial portions of the biopsy specimen. In cases with only focal involvement by giant-cell arteritis, this loss of material may hinder the establishment of a definitive diagnosis based on permanent sections.

John H. Stone, M.D., M.P.H.
Steven D. Brass, M.D., M.P.H.
James R. Stone, M.D., Ph.D.
Massachusetts General Hospital, Boston, MA 02114

2 References

1. 1

   Boyev LR, Miller NR, Green WR. Efficacy of unilateral versus bilateral temporal artery biopsies for the diagnosis of giant cell arteritis. Am J Ophthalmol 1999;128:211-215
   CrossRef | Web of Science | Medline

2. 2

   Pless M, Rizzo JF III, Lamkin JC, Lessell S. Concordance of bilateral temporal artery biopsy in giant cell arteritis. J Neuroophthalmol 2000;20:216-218
   CrossRef | Web of Science | Medline