IgG4-related Disease Concomitant with Diffuse Large B-cell Lymphoma

Area of Science:

• Oncology
• Immunology
• Pathology

Background:

• Diffuse large B-cell lymphoma (DLBCL) and IgG4-related disease (IgG4-RD) are distinct conditions that can affect lymph nodes and salivary glands.
• Simultaneous occurrence of DLBCL and IgG4-RD is uncommon, posing diagnostic challenges.

Purpose of the Study:

• To report a rare case of concurrent DLBCL and IgG4-RD in a 77-year-old male.
• To highlight the importance of comprehensive histopathological evaluation in cases with unusual organ involvement.

Main Methods:

• Clinical presentation of right inguinal lymphadenopathy and bilateral parotid/submandibular gland swelling.
• Histopathological examination of inguinal lymph node revealing germinal center B-cell type DLBCL.
• Submandibular gland biopsy showing lymphocyte and plasma cell infiltration with elevated serum IgG4 levels, leading to IgG4-RD diagnosis.
• Assessment of treatment response using fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT).

Main Results:

• Diagnosis of DLBCL and IgG4-RD confirmed through biopsies.
• Systemic chemotherapy for DLBCL resulted in significant reduction of lymphadenopathy and submandibular gland swelling.
• FDG-PET/CT confirmed treatment efficacy.

Conclusions:

• Concurrent DLBCL and IgG4-RD, while rare, necessitates thorough investigation.
• Biopsy of all affected organs is critical for accurate diagnosis and management of simultaneous conditions.
• This case underscores the complexity of diagnosing overlapping lymphoproliferative and autoimmune disorders.