In patients with probable primary amyloidosis, multiple myeloma and rheumatoid arthritis, we studied whether lip biopsy was useful for definite diagnosis of amyloidosis, and whether there was a difference in the location and the degree of amyloid deposition between the minor salivary gland of the lip and the labial mucosa.
Amyloid deposition was seen in 20 (33, 3 %) of the examined 60 patients. In six of these 20 patients who were diagnosed as positive by lip biopsy, biopsy specimens were taken from other organs and they also showed amyloid deposition. In six of 40 cases having showed negative results by the lip biopsy, the biopsy of other organs was performed. Only one case that received stomach biopsy showed positive deposition.
In 25 cases, the biopsy specimens were simultaneously taken from the labial mucosa and the labial glands, and both tissues showed the same result about amyloid deposition. But, amyloid deposition in the labial gland was more apparent than that in the labial mucosa. In the labial gland, amloid depositi on was obvious in the periductal, periacinar and perivascular tissues, while in the labial mucosa it was recognized in the stroma and perivascular tissues.
The degree of amyloid deposition was compared among primary amyloidosis, multiple myeloma and rheumatoid arthritis, and in the patient with rheumatoid arthritis amyloid deposition was more apparent.
Lip biopsy provides reliable information on amyloid deposition. A biopsy procedure is simple and has no complications.
We think lip biopsy is the best examination choice for definite diagnosis of amyloidosis, and the minor salivary gland is more suitable for diagnosis.
