3. Clinical presentation, diagnosis and staging

#### 3.1. Clinical presentation

Patients typically present with a rapidly enlarging single or multiple masses. In case of lymph nodes, enlargement usually involves cervical or the abdominal lymph nodes. The primary mediastinal DLBCL presents as a mediastinal mass. Patients with early stage (I/II) disease often presents with extranodal involvement. These comprise of about 40% of cases [42], while remainder 60% present with stages III/IV disease [43]. Extranodal disease is often seen in elderly patients with poor performance status and lower disease burden [42]. In a series published by Guillermo et al. extranodal gastrointestinal tract involvement was noted to be the most frequent in 12% of all cases, with majority of the lesions being in stomach; other regions included 4.5% soft tissue, 2.5% central nervous system (CNS), 2% each of liver and bone, 1% of skin, breast, kidney, testis/ovaries, and the remainder <1% each of thyroid, bone marrow, lung, prostate, uterus and pericardium [44]. Presenting symptoms may be related to the rapidly enlarging mass depending upon the site of the mass; B symptoms such as fever, night sweats, weight loss may be seen in about 30% of patients [43]. Some may present with hypercalcemia of unknown origin with imaging work up leading to diagnosis of lymphoma. Others may present with oncologic emergencies such as spinal cord compression, superior vena cava syndrome, acute airway obstruction, CNS mass lesions, renal failure due to hydronephrosis and liver failure.

#### 3.2. Diagnosis

Diagnosis of DLBCL needs an expert hematopathologist with expertise in hematologic malignancies. An incisional or excisional lymph node biopsy is recommended when possible, to establish the diagnosis. This allows evaluation of the lymph node architectural details. Core needle biopsy is not encouraged. FNA is not suitable for the initial diagnosis although it may be sufficient to establish the relapse.

#### 3.3. Immunophenotype

platform that can run on FFPE tissue. Twenty genes have been selected out of 93 candidate genes [38, 39] to identify COO using this platform. In NanoString technology, digitally colored code sets are attached to the sequence-specific probes to directly measure mRNA [28, 40]. This technique offers highly sensitive, quantitative and reproducible results on FFPE and frozen tissue samples. This requires a very small amount of RNA and covers a large number of genes enabling complex genetic analysis. Studies have demonstrated strong concordance between patient-matched frozen and FFPE materials. It showed 98% concordance for ABC/GCB and 95% in the unclassifiable cases when compared with GEP [38]. In a study on 82 patients, who were treated with R-CHOP the concordance rate between Lymph2Cx assay and Hans algorithm was 73.6%. The outcome of Lymph2Cx-defined ABC (77.1%) was significantly poor as compared to the GCB type (96.6%). On contrary, there was no difference in the outcome of two

Patients typically present with a rapidly enlarging single or multiple masses. In case of lymph nodes, enlargement usually involves cervical or the abdominal lymph nodes. The primary mediastinal DLBCL presents as a mediastinal mass. Patients with early stage (I/II) disease often presents with extranodal involvement. These comprise of about 40% of cases [42], while remainder 60% present with stages III/IV disease [43]. Extranodal disease is often seen in elderly patients with poor performance status and lower disease burden [42]. In a series published by Guillermo et al. extranodal gastrointestinal tract involvement was noted to be the most frequent in 12% of all cases, with majority of the lesions being in stomach; other regions included 4.5% soft tissue, 2.5% central nervous system (CNS), 2% each of liver and bone, 1% of skin, breast, kidney, testis/ovaries, and the remainder <1% each of thyroid, bone marrow, lung, prostate, uterus and pericardium [44]. Presenting symptoms may be related to the rapidly enlarging mass depending upon the site of the mass; B symptoms such as fever, night sweats, weight loss may be seen in about 30% of patients [43]. Some may present with hypercalcemia of unknown origin with imaging work up leading to diagnosis of lymphoma. Others may present with oncologic emergencies such as spinal cord compression, superior vena cava syndrome, acute airway obstruction, CNS mass lesions, renal failure due to

Diagnosis of DLBCL needs an expert hematopathologist with expertise in hematologic malignancies. An incisional or excisional lymph node biopsy is recommended when possible, to establish the diagnosis. This allows evaluation of the lymph node architectural details. Core needle biopsy is not encouraged. FNA is not suitable for the initial diagnosis although it may

groups classified by the Hans algorithm [41].

48 Hematology - Latest Research and Clinical Advances

3.1. Clinical presentation

hydronephrosis and liver failure.

be sufficient to establish the relapse.

3.2. Diagnosis

3. Clinical presentation, diagnosis and staging

It is essential for the differentiation of various subtypes of DLBCL. This is established either by flow cytometry or IHC. Flow cytometry can be employed in determining bone marrow involvement [45] when PET/CT is not readily available for staging and in determining CNS involvement by CSF flow cytometry [46]. Immunophenotype findings are usually combined with morphologic findings to arrive at a diagnosis. Tumor cells in DLBCL generally express pan B cell antigens (CD19, CD20, CD22, and CD79a) as well as CD45. The typical immunophenotype is CD20+, CD45+, and CD3. The panel should include CD20, CD3, CD5, CD10, CD45, BCL2, BCL6, Ki-67, IRF4/MUM1, and MYC. 50–75% of tumors express surface and cytoplasmic monoclonal immunoglobulin (Ig). The proliferative fraction of cells is usually higher than 40% and may occasionally be >90%. CD5 positive tumors are associated with a more aggressive disease and a higher incidence of CNS involvement and a worse prognosis. CD10+ and BCL6+ indicates GCB lymphoma while MUM1+ indicates ABC lymphoma. The three most common translocations noted in DLBCL include MYC, BCL2 and BCL6. MYC is an oncogene involved in pathogenesis of aggressive lymphomas based on partner gene translocation. MYC protein is a transcription regulator for cellular proliferation acting on metabolic and angiogenic mechanism. Genetic translocation involving MYC are considered primary events in 5–15% of DLBCL [47] and in around 20% on first relapse [48]. In DLBCL frequently the partner gene is BCL-2 or to a lesser extent BCL-6 or both, in the so-called double-hit or triple-hit lymphomas. Overexpression of MYC protein can be tested with IHC which can occur independent of translocation in 30% of cases; however for confirmation of specific translocation FISH studies are required [49]. Both, overexpression and translocation confer adverse outcome as documented in different studies [50]. More information on this translocation and their effect on outcome is detailed in Sections 2.3 and 6.2.

#### 3.4. Workup

Initial work up includes thorough physical examination with special attention to node bearing areas and evaluation of performance status (PS) and constitutional symptoms. Appropriate site for excisional/incisional biopsy should be earmarked as stated above. Laboratory assessments include complete blood count (CBC) with differential, complete metabolic profile (CMP), lactate dehydrogenase (LDH) and Beta-2 microglobulin. Additional tests including uric acid and phosphorus, in patients with high tumor burden. Hepatitis B virus (HBV) testing is also warranted as there is an increased risk of HBV reactivation in patients who may require Rituximab. Positron emission tomography (PET)/computed tomography (CT) scan is recommended for initial staging as upstaging can result in altered therapy. Also baseline PET/ CT is necessary to confirm the response on the post treatment PET scans. A systematic review and meta-analysis by Adams et al. showed that sensitivity and specificity of PET/CT for detection of bone marrow involvement ranged from 70.8 to 95.8% and from 99.0 to 100%, respectively [51]. There were 3.1% patients who were PET negative but had bone marrow involvement on bone marrow biopsy. On contrary 12.5% patients with negative bone marrow biopsies had marrow involvement on PET scan and PET/CT [51]. Bone marrow biopsy is not needed if the PET/CT is negative unless finding another concomitant lymphoma is important in treatment decision. Another study showed that the incidence of bone marrow involvement was 3.6% in 192 patients with stage I and II DLBCL [52]. Echocardiogram or multigated acquisition (MUGA) scan if required if anthracycline-based regimen is being considered. In selected cases discussion of fertility issues and sperm banking should be considered. Consider lumbar puncture if there is suspicion of CNS disease or if patient is at high risk of CNS involvement such in patients with testicular lymphoma, aggressive histology, human immunodeficiency virus (HIV) lymphoma, double-expressor lymphoma and in patients with 4–6 factors on the prognostic score which is discussed in the section on CNS prophylaxis. The role of various imaging modalities has been reviewed in detail elsewhere [53].

considers more than or equal to 7.5 cm as bulky disease. A single nodal mass of 10 cm or greater than third of the transthoracic diameter is the definition of bulky disease only for

Recent Advances in Diffuse Large B Cell Lymphoma http://dx.doi.org/10.5772/intechopen.74263 51

Staging has limited prognostic value due to the heterogeneity of the disease. To fully incorporate prognostic information several models have been developed to predict survival. The staging should generally be used with these prognostic models for accurate information.

In oncology, the focus of imaging modalities is drifting from morphological to functional imaging and combined PET/CT is making its foray in each step of DLBCL management. Bone marrow evaluation is a part of staging that upstages DLBCL to stage IV if positive. Focal positivity on PET/CT scan can obviate the need for bone marrow biopsy in staging these patients. In a study where it was compared to standard bone marrow biopsy, PET/CT showed higher sensitivity, accuracy and negative predictive value (94, 98 and 98%, respectively, for PET/CT vs. 24, 80 and 81% for bone marrow examination) [56]. Similarly PET/CT has established its role in response assessment (see Section 7.6). Interim PET/CT can be used as a predictive marker for prognosis with PET response in the interim denoting better outcomes. In a study [57] negative PET/CT after 2 cycles when compared to those who had positive scans, showed significantly higher CR (97.3 vs. 33.3%), 3-year PFS (75.8 vs. 38.2%) and 3-year OS rates (93.5 vs. 55.6%). This advantage was also seen in those patients whose PET/CT was negative after 4 cycles and showed higher CR (96.9 vs. 16.2%), 3-year PFS (75.3 vs. 24.7%) and 3-year OS rate (91.6 vs. 49.4%).

Includes wide range of pathologies that cause lymphadenopathy such as infectious mononucleosis, Carcinoma, anaplastic large cell lymphoma, gray zone lymphoma, Burkitt's lymphoma, rarely pathologies that cause small blue round cells such as Ewing's sarcoma may be

Several distinct subtypes of large B cell lymphoma need to be distinguished from DLBCL, NOS

Hodgkin's lymphoma.

4. Differential diagnosis

in the differential diagnosis.

5. Subtypes

(see sec 2.6 above) [8].

2. Gray zone lymphoma.

1. Primary mediastinal (thymic) B cell lymphoma

3. T cell/histiocytes rich large B cell lymphoma. 4. DLBCL associated with chronic inflammation.

3.6. Role of PET/CT in management of DLBCL

#### 3.5. Staging

Ann Arbor staging system was originally introduced for Hodgkin's lymphoma and was later adopted for NHL. Lister et al. classified patients with NHL into stages I (localized) to IV (extensive) disease [54]. Patients are classified into A or B depending on the absence or presence of B symptoms, respectively. B symptoms mainly include fevers, drenching night sweats or weight loss of 10% or more within 6 months of diagnosis. DLBCL is a noncontiguous disease while Hodgkin's lymphoma involves contiguous sites hence the Ann Arbor staging has limited utility in DLBCL. In 2014, the Lugano classification was proposed (Table 1) [55]. According to this classification, patients with stage I or II disease can be grouped and considered as having limited disease while patients with Ann Arbor stage III or IV disease can be grouped as advanced stage disease. The suffix A and B is only reserved for Hodgkin's lymphoma. The X for bulky disease is now replaced with the recording of the largest nodal diameter by CT scan. Limited evidence suggests that 6–10 cm should be considered as bulky disease in the rituximab era for DLBCL. National comprehensive cancer network (NCCN)


Note: Extent of disease in DLBCL is determined by PET-CT or CECT if former is not available. Tonsils, Waldeyer's ring, and spleen are considered nodal tissue.

1 The decision to treat stage II bulky disease as limited or advanced disease is determined by the histology and IPI.

Table 1. Revised staging system for primary nodal lymphomas.

considers more than or equal to 7.5 cm as bulky disease. A single nodal mass of 10 cm or greater than third of the transthoracic diameter is the definition of bulky disease only for Hodgkin's lymphoma.

Staging has limited prognostic value due to the heterogeneity of the disease. To fully incorporate prognostic information several models have been developed to predict survival. The staging should generally be used with these prognostic models for accurate information.
