No diagnostic criterion is infallible. Occasionally the most dependable symptom or sign may be absent. When the cardinal signs of a given disease are present, the diagnosis is usually arrived at with facility. When the nature of an ailment remains obscure because of the absence of the classic occurrences peculiar to that disease, diagnostic criteria often thought to be of lesser import attain an unusual significance.
In his "Introduction to Surgery," Rutherford Morison1 mentions a diagnostic sign of gummatous ulcer that merits more serious attention by physicians in the differential diagnosis of such ulcers. Syphilitic ulcers, he says, choose the midline where the blood supply is normally the least.
In the case reported here, a diagnosis was arrived at solely through the presence of an ulcer in the midline over the sternum, suggesting the possibility that the ulcer as well as the major complaint of pain and ulceration in