Introduction

Lymphoma with Mott cell differentiation (MCL) is known to be an uncommon variant of canine lymphoma. Although it has been described in several case reports/series, there is no comprehensive study to characterize this type. In Japan, we sometimes experience cases with MCL in Miniature Dachshunds (MDs), a popular breed in our country. This study was aimed to demonstrate its clinical characteristics and outcomes.

Methods

Medical records of MDs diagnosed with lymphoma at Veterinary Medical Center of the University of Tokyo (2008–2017) were evaluated. MCL was diagnosed when cytology revealed neoplastic cells in lymphoma to differentiate into Mott cells having abundant Russel bodies in cytoplasm.

Results

Medical records of 113 MDs diagnosed with lymphoma were collected. Cytology specimens could be re- evaluated in 87 dogs. Of the 87 dogs, 9 dogs (10%) were diagnosed with MCL. All 9 dogs were categorized into alimentary lymphoma from the tumor locations (small and/or large intestine, 6 dogs; mesenteric lymph node, 3 dogs). Median age was 3 years old (range, 1–9 years). All 9 dogs were treated with chemotherapies including (L-)CHOP, melphalan and chlorambucil. Overall response rate was 78% (7/9). Overall survival in these 9 dogs ranged from 6 to >1,513 days (median: 240 days), significantly longer than that in 29 MDs with alimentary large cell lymphoma other than MCL (range: 0–>3,801 days, median: 57 days) (P=0.0491).

Conclusion

Alimentary MCL was occasionally diagnosed in relatively young MDs. Its prognosis was better than that of alimentary lymphoma other than MCL.

Funding Information

No funding was used for this project.