DISCUSSION
Based on one of the recent studies, primary vulvar DLBCL is bi-modally
distributed between the age group of 25 to 43 and 62 to 79 with a mean
age of 58. Our patient is a 79-year-old elderly woman. Clinically, the
patient with vulvar DLBCL may present with complaints of tender to
non-tender mass with or without ulceration. Erythema, edema, and
pruritus may also be present.4 Our patient presented
with the complaint of a hard nodule in the right labia majora, which
appeared to be an ulcerative peri-urethral mass on examination.
Since there are only a few reported cases of primary vulvar DLBCL in
medical literature, it might be diagnostically challenging. The
differential diagnosis for vulvar DLBCL ranges from inflammatory
lymphoid conditions (lichenoid dermatoses, extramedullary myeloid cell
tumor, Langerhans cell granulomatosis) to carcinomas (Neuroendocrine
carcinomas like Merkel cell or metastatic, lymphoepithelioma-like,
poorly differentiated squamous cell, Bartholin’s gland adenocarcinoma)
and other conditions like melanoma, rhabdomyosarcoma, extraosseous
Ewing’s sarcoma/primitive neuroectodermal tumor, lipoma, and Bartholin
gland cyst or abscess.5 Pelvic MRI emerges as the most
effective imaging tool for this purpose.6,7
In cases of DLBCL, the typical IHC analysis findings involve large,
abnormal lymphocytes that are negative for CD3 but positive for CD20,
exhibiting a Ki-67 labeling index surpassing 80%. To determine the cell
of origin, staining for CD10, Bcl-6, and MUM-1 is conducted using the
Hans algorithm.8 Confirmation of the double-expression
phenotype involves staining for Bcl-2 and c-myc.9Additionally, Epstein-Barr virus in situ hybridization staining assists
in identifying EBV-positive DLBCL. In some instances, DLBCL may be
suspected despite negative findings for CD3 and CD20 in H&E staining.
In such scenarios, it’s important to entertain the likelihood of a
poorly differentiated carcinoma or a small round-cell tumor as part of
the standard diagnostic process. Nevertheless, the spectrum of potential
diagnoses broadens to include CD20-negative DLBCL and anaplastic
large-cell lymphoma (ALCL) when lymphoma is under
consideration.10
In our case, immunohistochemistry analysis revealed the tumor cells were
positive for CD20, BCL6, MUM1, CMYC, and BCL2 and negative for CK, CD3,
CD10, SOX11, and Ki67 70%.
The primary treatment used for vulvar lymphoma is typically R-CHOP
therapy, sometimes followed by radiotherapy. Recent studies have
highlighted the significance of the cell type causing DLBCL, with
Activated B Cell (ABC) and Germinal Centre B Cell (GCB) DLBCLs showing
varying responses to standard treatment like rituximab and CHOP
chemotherapy (R-CHOP). Patients with GCB-DLBCL usually respond well to
R-CHOP, while those with ABC-DLBCL may not.11,12
In comparison to nodal NHL, genital lymphomas seem to be less aggressive
and show a very low incidence of recurrence. The prognosis of the
genital lymphomas appears to be very good with a 5-year survival rate
occurring between 80 and 90%.13–15