21 September 2026
: Case report 
Simultaneous Thyroid Eye Disease and IgG4-Related Orbital Disease in a Patient With Diabetes Mellitus: A Case Report
Challenging differential diagnosis, Diagnostic / therapeutic accidents, Management of emergency care, Educational Purpose (only if useful for a systematic review or synthesis), Rare coexistence of disease or pathology
Brenda Hayatulhaya ABCDEF 1*, Tomoyuki Kashima ABCDEFG 2DOI: 10.12659/AJCR.952068
Am J Case Rep 2026; 27:e952068
Table 1 Histopathological criteria for IgG4-related orbital disease.
| Histopathological feature | Findings in IgG4-RD | Findings in this case |
|---|---|---|
| Lymphoplasmacytic infiltrate | Dense infiltrate of lymphocytes and plasma cells | Present |
| Fibrosis | Storiform or irregular fibrosis | Present |
| Obliterative phlebitis | Can be present, not mandatory in orbital disease | focally suspected |
| IgG4-positive plasma cells | Increased number on immunohistochemistry | Present |
| IgG4+ / IgG+ plasma cell ratio | > 40% (diagnostic threshold) | > 40% |
| Serum IgG4 level | Can be elevated or normal | Elevated (123 mmg/dL) |
| Evidence of malignancy | Absent | Absent |