[1463] Salivary Gland Lymphoproliferative Disorders: A Canadian Experience

Manisha Lamba, Aleksandra Paliga, Isabelle Bence-Bruckler, James Farmer. The Ottawa Hospital, Ottawa, Canada

Background: Salivary gland lymphoproliferative disorders (SGLD) include a spectrum of disorders ranging from benign lymphoepithelial lesions to overt low and high grade B-cell lymphoma. These are very rare tumors and clinicopathological data is sparse. We looked at SGLD in the Canadian population.
Design: 30 cases were extracted from the surgical pathology files of the Ottawa Hospital between 1990 and 2011. We conducted clinical, histopathological, and immunophenotypic analysis on all cases, and molecular genetic analysis in a subset of cases.
Results: 22/30 patients presented with enlargement of the parotid gland (PG) while 7/30 presented with submandibular gland (SG) enlargement, and 1/30 with a mass of the hard palate. There were 15 primary lymphomas with lesions confined to PG (11) and SG (4). Please refer to table 1 for classifications and median age. All primary lymphomas were stage IE, all were treated with excision, and most received additional radiation and/or chemotherapy. Follow-up varied from 1-16 years (median 4). 6 patients had recurrent disease at a distant site, varying from 1-9 years (median 3.5), but there were no lymphoma related deaths.
7 secondary lymphomas were identified; 5 in the PG and 2 in the SG. All patients presented with stage IV disease except one who had stage IIIE disease. Lymphomas were classified as described in table 1. Most were treated with chemotherapy, including 4 with the addition of Rituximab. All, but one, relapsed.

Table 1: Comparison of Primary vs. Secondary Salivary Gland Lymphoma Histology

	Primary (15 Total)	Secondary (7 Total)
Mean age in years (median)	67(63)	66(57)
Male	40%	43%
Histology
MALT	6/15
Follicular	5/15	2/7
DLBCL	4/15	3/7
SLL		2/7

5/30 patients were diagnosed with lymphomas originating from intra-parotid lymph nodes. Finally, the remaining 3/30 cases represented reactive sialadenitis.
Molecular genetic analysis was performed in 9 cases with small lymphocytic morphology. 7 had a monoclonal rearrangement in the immunoglobulin heavy chain gene IgH, while 4 lymphomas showed the t (14;18) translocation typical of follicular lymphoma.
Conclusions: SGLD's are predominantly B-cell lymphomas that develop in older adults. Primary tumors, which have MALTL and low grade FL characteristics, have a favorable survival. Molecular genetic studies may be useful in cases with small lymphocytic morphology.
Category: Hematopathology

Monday, March 19, 2012 1:00 PM

Poster Session II # 218, Monday Afternoon