Primary Bone Marrow B-Cell Lymphoma Undetected by Multiple Imaging Modalities That Initially Presented with Hypercalcemia

Missed diagnosis of lymphoma presenting with humoral hypercalcemia of malignancy due to cessation of oncological workup after negative computed tomography scans

Malignancy is the most common cause of hypercalcemia among hospitalised patients and is frequently caused by elevations in parathyroid hormone-related peptide (PTHrP). The most common PTHrP-producing cancers are carcinomas of the head, neck and lung. Hypercalcemia can be the presenting sign of cancer and, in these cases, solid tumours are usually discovered on CT scan. In rare cases, lymphoma may also present with hypercalcemia. CT scan is less sensitive for lymphoma than for most solid tumours and the diagnosis may be missed. We present the case of a 69-year-old woman who presented with hypercalcemia in the setting of severe weight loss and elevated PTHrP. Oncological workup was stopped after unrevealing CT scans and an underlying lymphoma was missed. Our case emphasises the need for a comprehensive oncological workup for patients with unexplained hypercalcemia and elevated PTHrP, even when CT scans are unrevealing.

Aggressive Diffuse Intermediate Size B-Cell Lymphoma With P53 Mutation Presented as Primary Bone Marrow Lymphoma

Primary bone marrow lymphoma (PBML) is a disease entity in which lymphoma primarily originates in the bone marrow without signs of involvement of lymph nodes, spleen, liver, or any other organs, and excludes leukemia/lymphoma. PBML has been a rare presentation of malignant lymphoma, and most of the cases have a poor prognosis and require rapid diagnoses and treatments. Among all PBMLs, diffuse large B-cell lymphoma (DLBCL) is the most common pathological subtype. Over 25 years and from 7 institutions, the International Extranodal Lymphoma Study Group retrospectively collected PBML cases and, in 2012, published these 21 cases, including 19 cases of B-cell lymphoma and 2 cases of peripheral T-cell lymphoma. Among the B-cell types, DLBCL accounted for 79% and follicular lymphoma (FL) for 21%. DLBCLs were characterized by the existence of large cells. In this article, we present a rare case of high-grade aggressive type with P53 mutation, intermediate-sized B-cell lymphoma, excluded FL by the absence of FL lymphoma markers, presented as PBML. Our patient had rapid progression and succumbed to the disease shortly after diagnosis. Upon literature review, 62 B-cell lymphoma cases were identified that presented as PBML (51 high-grade and 11 low-grade)—mostly case reports. Among these, only one case was reported as intermediate-sized DLBCL-like lymphoma but not with aggressive features. Our case represents the first case of aggressive intermediate-sized lymphoma, not a FL, with P53 mutation, highly elevated lactate dehydrogenase, and Ki-67 presented as PBML. Such a profile would need to be quickly recognized and aggressive treatment applied, such as CART (chimeric antigen receptor T-cells) therapy or DA-EPOCH-R (dose-adjusted EPOCH [etoposide-prednisone-oncovin-cyclophosphamide-hydroxydaunorubicin] and rituximab) with or without venetoclax.

Bone Marrow Burkitt Lymphoma in a Child

Burkitt lymphoma (BL) is a highly aggressive but potentially curable disease as long as adequately treated within due time. BL may occur primarily and exclusively in the bone marrow as a form of peripheral and extranodal disease. BL cases with isolated bone marrow involvement are challenging in regard to a prompt diagnostic process. We report a case of a sporadic extranodal subtype of isolated bone marrow BL in an 11-year-old boy. Bone marrow aspiration and biopsy, flow cytometry, and immunohistochemistry along with cytogenetics are compulsory in order to achieve the adequate diagnosis.

Hypercalcemia in T-Cell/Histiocyte-Rich Large B-Cell Lymphoma: An Unusual Presentation of a Rare Disease and Literature Review

T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) is an extremely rare morphologic subtype of diffuse large B-cell lymphoma (DLBCL), accounting for only 1-3% of total cases. It is considered an aggressive lymphoma with a poor prognosis. Hypercalcemia has been described as an uncommon presenting symptom of patients with DLBCL in several case reports. Here, we report an unusual case of severe hypercalcemia in a patient who was ultimately diagnosed with T-cell/histiocyte-rich B-cell lymphoma. A 69-year-old male patient presented to our hospital with nausea, vomiting, weakness and unintentional weight loss. His initial blood tests showed a serum calcium level of 16.1 mg/dL and serum creatinine level of 3.25 mg/dL. He had high intact parathyroid hormone (PTH, 6.8 pg/mL), mildly elevated 25-hydroxyvitamin D and serum PTH-related peptide (PTHrP). To exclude malignancy, computed tomography (CT) scans of the chest, abdomen and pelvis were performed which were unremarkable. A bone marrow biopsy was performed to detect any hidden hematologic malignancy which showed large mononuclear cells with prominent nucleoli and occasional Reed-Sternberg cells, consistent with the diagnosis of THRLBCL. Subsequent positron emission tomography demonstrated diffuse fluorodeoxyglucose (FDG) uptake. This case reports a unique presentation of a rare subtype of non-Hodgkin's lymphoma. We highlight the importance of pursuing a thorough workup for causes of hypercalcemia as well as understanding the underlying mechanisms of severe hypercalcemia in malignancy.