High incidence of lymphoid infiltration on labial salivary gland biopsy in non-Hodgkin's lymphomas: clinical implications.

Sjögren's syndrome (SS) is characterized by an increased risk of developing a non-Hodgkin's lymphoma (NHL). We performed labial salivary gland biopsy (LSGB) in 103 patients with untreated NHL, negative for human immunodeficiency virus. Median age was 58 years (range 21-79) and M/F 1.3. Using the Working Formulation, 37 patients had low-grade NHL and 66 had intermediate- or high-grade NHL. Dense lymphocytic infiltration (positive focus score 3 or 4) was found in 28 patients. 10 (35%) of these 28 patients fulfilled criteria for possible SS. 15/28 patients had an identical monotypic infiltrate on LSGB and NHL tissue (including two of the 10 patients with criteria for SS). The significance of the lymphoid infiltrate of LSGB was unknown in the five remaining patients with positive focus score. Significant correlations were found between positive focus score and presence of two or more extranodal sites of disease (P = 0.02), impaired performance status (P = 0.004), splenomegaly (P = 0.05), increased gammaglobulin level (P = 0.03), and beta 2 microglobulin (P = 0.004). Considering intermediate- or high-grade NHL, we found significant correlation between positive focus score and unfavourable prognosis according to the two Dana Farber Cancer Institute indexes (P < 0.04), to the LNH-84 index (P = 0.05), and to the international index (P = 0.003). In conclusion, systematic evaluation of LSGB in 103 patients with NHL found lymphoid infiltration in 28% of them, but possible SS could be considered in only 10%. This lymphoid infiltration, though not correlated with any particular histological subtypes, was associated with unfavourable clinical prognostic factors, especially in intermediate- or high-grade NHL.