Case report highlights DWI MRI signal in feline orbital lymphoma
Bottom line
A new case report in Veterinary Radiology & Ultrasound describes a 10-year-old Turkish Angora cat with an orbital mass and a pulmonary mass evaluated with MRI plus diffusion-weighted imaging, or DWI. The authors report restricted diffusion in both lesions, a pattern consistent with lymphoma, and say this is the first published description of restricted diffusion on DWI in feline orbital lymphoma and presumptive pulmonary lymphoma. The report adds to a small but growing veterinary literature suggesting DWI can help distinguish feline lymphoma from other tumor types when conventional imaging findings overlap. (onlinelibrary.wiley.com)
Why it matters: For veterinary professionals, the practical takeaway is about diagnostic confidence. Orbital neoplasia in cats is common, and lymphoma is among the diagnoses clinicians routinely consider in orbital and retrobulbar disease, but imaging findings can be nonspecific. Prior feline studies have shown low apparent diffusion coefficient values and DWI hyperintensity in CNS, nasal, and nasopharyngeal lymphoma, while human orbital imaging literature also supports restricted diffusion as a useful clue for lymphoma over inflammatory or other mass lesions. This case extends that concept to the feline orbit, and potentially to pulmonary involvement, which has historically shown variable appearance on thoracic imaging. (pubmed.ncbi.nlm.nih.gov)
What to watch: Watch for larger case series that test whether DWI and ADC thresholds can reliably separate feline lymphoma from other orbital and thoracic masses in everyday referral practice. (journals.sagepub.com)
Key facts
- Journal
- Veterinary Radiology & Ultrasound
- Species
- Cat
- Age
- 10-year-old
- Breed
- Turkish Angora
- Findings
- Orbital mass and pulmonary mass
- Imaging
- MRI with diffusion-weighted imaging (DWI)
- Key result
- Restricted diffusion in both lesions
- Interpretation
- Consistent with lymphoma
- First report
- First published description of restricted diffusion on DWI in feline orbital lymphoma and presumptive pulmonary lymphoma
A newly published feline imaging case report points to a potentially useful MRI marker for a difficult diagnostic problem: telling lymphoma apart from other orbital and thoracic masses. In Veterinary Radiology & Ultrasound, Sang-Kwon Lee, Sunjun Jung, Min Jang, and Kija Lee describe a 10-year-old Turkish Angora cat with orbital and pulmonary masses in which diffusion-weighted MRI showed restricted diffusion in both lesions, supporting a diagnosis of orbital lymphoma with presumptive pulmonary lymphoma. The authors identify it as the first report of this imaging pattern in those feline disease sites. (onlinelibrary.wiley.com)
The report lands in an area where veterinary evidence is still fairly thin. In cats, DWI has previously been described in CNS lymphoma, nasopharyngeal lymphoma, and nasal lymphoma, with those reports suggesting lymphoma tends to appear hyperintense on DWI and to have relatively low apparent diffusion coefficient, or ADC, values compared with other lesions. A 2021 Journal of Feline Medicine and Surgery study, for example, found all seven cats with nasal lymphoma were hyperintense on DWI and had a median ADC of 0.45 × 10−3 mm²/s, lower than the two nasal adenocarcinomas in that series. (pmc.ncbi.nlm.nih.gov)
That matters because orbital disease in cats can be diagnostically messy. A review of feline orbital neoplasia found lymphoma among the most common diagnoses, and a larger retrobulbar neoplasia series reported lymphoma as the most common diagnosis overall, accounting for 19 of 37 cases. Imaging can help localize disease, but it doesn't always cleanly separate neoplasia from inflammation or distinguish one tumor type from another. Older MRI review data also noted that feline orbital lymphoma was generally unilateral and often originated from the ventromedial orbit. (pubmed.ncbi.nlm.nih.gov)
The pulmonary component adds another layer of interest. The case report describes the lung lesion as presumptive pulmonary lymphoma, and that label is important because pulmonary lymphoma in cats has long been recognized as radiographically variable. In a Veterinary Radiology & Ultrasound study of confirmed pulmonary lymphoma in cats and dogs, thoracic radiographic findings ranged from normal to alveolar or interstitial infiltrates, nodules or masses, bronchial changes, pleural effusion, and lymphadenopathy. In other words, thoracic imaging can raise suspicion, but pattern recognition alone may not be enough. (onlinelibrary.wiley.com)
Outside veterinary medicine, the broader diffusion-MRI literature helps explain why this finding is plausible. Human orbital imaging studies have shown that lymphoma often demonstrates restricted diffusion and low ADC values because of high cellularity, and DWI has been reported as useful for distinguishing orbital lymphoma from inflammatory lesions and other orbital masses. That doesn't make direct veterinary extrapolation automatic, but it does provide biologic support for what this feline case observed. (pubs.rsna.org)
Why it matters: For veterinary radiologists, oncologists, neurologists, and ophthalmology teams, this report is less about changing standard of care tomorrow and more about sharpening the diagnostic toolkit. When a cat presents with exophthalmos, retrobulbar disease, or a mass with possible thoracic spread, DWI may offer another noninvasive data point that helps prioritize lymphoma on the differential list, guide biopsy planning, and frame conversations with pet parents earlier in the workup. The catch is that this is still a single case report, and veterinary MRI access, protocol consistency, and validated ADC cutoffs remain limiting factors. (pubmed.ncbi.nlm.nih.gov)
There doesn't appear to be a separate institutional press release or broad industry reaction tied to this paper, which is common for niche clinical imaging case reports. Still, the publication fits a visible trend: diffusion-weighted MRI is gradually gaining traction in veterinary oncology and neurology, including recent proof-of-concept work in canine lymphoma staging and earlier work in feline nasal and CNS disease. (link.springer.com)
What to watch: The next meaningful step will be replication in larger feline cohorts, especially studies that compare orbital lymphoma with inflammatory disease, carcinoma, sarcoma, and other retrobulbar masses, and that test whether ADC values can be standardized enough to support routine clinical decision-making. (pubmed.ncbi.nlm.nih.gov)