Gray zone lymphoma effectively treated with cyclophosphamide, doxorubicin, vincristine, prednisolone, and rituximab chemotherapy: A case report

Abstract

Background: B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and classical Hodgkin lymphoma (BCLu-DLBCL/cHL), also referred to as gray zone lymphoma (GZL), is known to share features with cHL and DLBCL. However, GZL is often difficult to diagnose. There is no consensus regarding the optimal therapeutic regimen. Most reported cases of GZL have been in Caucasian and Hispanic individuals, and its incidence is lower in African-American and Asian populations, including the Japanese population.

Case summary: A 69-year-old female presented at our hospital with a growing mass on the right side of her neck. An elastic, soft mass measuring 9 cm × 6 cm was palpable in the right cervical region. Laboratory analyses showed pancytopenia, increased serum lactate dehydrogenase levels, and markedly increased levels of soluble interleukin-2 receptor. Enhanced computed tomography (CT) and fluorodeoxyglucose positron emission tomography (PET)/CT revealed multiple lesions throughout her body. She was diagnosed with GZL based on the characteristic pathological findings, the immunophenotype [CD20+, PAX5+, OCT2+/BOB1 (focal+), CD30+, CD15-], and the strong positive expression of neoplastic programmed cell death protein ligand 1 (PD-L1) in her lymphoma cells. The lymphoma was stage IV according to the Lugano classification and high-risk according to the International Prognostic Index for aggressive non-Hodgkin lymphoma. The patient received cyclophosphamide, doxorubicin, vincristine, prednisolone, and rituximab (R-CHOP) chemotherapy because the tumor cells were CD20+. She has remained in complete remission for 3 years.

Conclusion: GZL was diagnosed based on histopathology and immunophenotyping with ancillary PD-L1 positivity. R-CHOP chemotherapy was an effective treatment.

Keywords: Case report; Classical Hodgkin lymphoma; Diffuse large B-cell lymphoma; Gray zone lymphoma; Programmed cell death protein ligand 1; R-CHOP.

Figure 1

Enhanced computed tomography showing a right cervical mass (A) and multiple low-density lesions in the liver and spleen (B).

Figure 2

Fluorodeoxyglucose positron emission tomography/computed tomography revealed multiple lesions throughout the patient’s body. A: Abnormal lymph node enlargement in the right neck, right clavicular region, and anterior mediastinum; B: Abnormal lymph node enlargement around the hepatic portal region, pancreatic head, and paraaortic region. Multiple nodular lesions in the liver and spleen; C: Multiple bone lesions in the left skull, thoracic and lumbar vertebrae, bilateral ribs, right clavicle, bilateral scapulae, lower end of the sternum, sacrum, bilateral ilia, left pubis, and bilateral femora.

Figure 3

Large lymphoma cells in the biopsied right supraclavicular lymph node. A: Sheet-like growth of atypical and pleomorphic cells and centroblastic cells (× 400). Inset: Fibrosis around the sheets of lymphoma cells (× 20); B: Large, atypical cells with some retracted pale cytoplasm scattered among the inflammatory cells (× 400).

Figure 4

Immunohistochemical staining of lymphoma cells. A: The cells were strongly and uniformly positive for CD20 (× 400); B: Strongly positive for PAX5 (× 400); C: Variably positive for CD30 [weakly positive (C1) or moderately to strongly positive (C2)] (× 400); D: Moderately to strongly positive for MUM1 (× 400); E: OCT2 was strongly positive for large atypical cells (80%); F: BOB1 strongly positive large atypical cells (inserted) were found in small numbers (< 10%).

Figure 5

Programmed cell death protein ligand 1 expression by lymphoma cells. Scattered large lymphoma cells, but not nonlymphoma cells, were strongly positive for programmed cell death protein ligand 1 (clone SP142) (× 200). Insert: Positive staining of the large lymphoma cell membrane was observed (× 400).