Precursor B-cell lymphoblastic leukemia as a cause of a bilateral nephromegaly

A rare cause of posterior reversible encephalopathy syndrome: Acute lymphoblastic leukemia

Key Clinical Message

The presentation of posterior reversible encephalopathy syndrome (PRES) as the initial presenting sign of acute lymphoblastic leukemia is unusual, as PRES is more often a complication of therapy. This case highlights the importance of maintaining a broad differential diagnosis for pediatric hypertension and its complications.

Abstract

A 6-year-old male presented with a seizure-like episode. Evaluation revealed hypertension and brain imaging showed findings consistent with posterior reversible encephalopathy syndrome. Complete blood count showed lymphoblasts, and the cause of his hypertension was determined to be renal infiltration of leukemia cells due to B-cell acute lymphoblastic leukemia.

Acute Lymphoblastic Leukemia Presenting as Fanconi Syndrome

Acute lymphoblastic leukemia (ALL) presenting as Fanconi syndrome (FS) is extremely rare. Here, we report a case of ALL presenting as bilateral nephromegaly following FS. A 2-year-old girl was unexpectedly diagnosed with bilateral nephromegaly. After 2 weeks, she developed general fatigue, thirst, and polyuria. Laboratory examinations revealed renal tubular acidosis, hypokalemia, hypophosphatemia, and aminoaciduria, and FS was diagnosed. Replacement of bicarbonate and potassium did not improve her condition. Two weeks after the onset of FS, leukemic cells appeared on a peripheral blood smear, and the patient was diagnosed with precursor B-cell ALL presenting as nephromegaly and FS. Chemotherapy brought about a prompt resolution of acidosis and electrolyte abnormalities, without renal dysfunction. The patient remains well 4 years after the onset of the disease. Although extremely rare, FS should be recognized as one of the emerging renal complications of ALL.

TdT-positive Infiltrate in Inflamed Pediatric Kidney: A Potential Diagnostic Pitfall

We encountered a patient with infantile nephrotic syndrome associated with a dense interstitial inflammatory infiltrate and prominent extramedullary hematopoiesis. Immunohistochemical analysis revealed numerous terminal deoxynucleotidyl transferase (TdT)-positive cells, which may raise concern for lymphoblastic lymphoma. Thus, we further characterized a group of pediatric kidneys with inflammation. TdT-positive nuclei were quantitated, and dual immunostains for TdT/CD79a, TdT/CD3, and TdT/CD43 were performed in a subset of cases; flow cytometry was performed in 1 case. TdT-positive nuclei were present in inflamed pediatric kidneys in 40 of 42 patients. TdT counts (average of 3 maximal high-power fields) ranged from 1 to >200, with a mean of 47. The presence and number of TdT-positive nuclei showed a strong association with younger patient age. Extramedullary hematopoiesis was identified in 11/42 patients, all under the age of 1. The presence of extramedullary hematopoiesis did not correlate with TdT count (P=0.158). Dual immunostaining and flow cytometric analysis in 1 case showed weak expression of B-cell markers and favored normal precursor B cells. Although TdT is a common marker of lymphoblastic lymphoma, we have demonstrated that TdT-positive cells may be part of the inflammatory milieu in infant kidneys. Together with cytologic, architectural, and clinical features, these data can help to avoid misinterpretation of involvement by lymphoblastic lymphoma/leukemia.

Lymphoblastic lymphoma presenting as bilateral renal enlargement diagnosed by percutaneous kidney biopsy: Report of three cases

Renal involvement by lymphoma can be a diagnostic challenge. Acute kidney injury (AKI) is an unusual manifestation of lymphomatous infiltration in the kidneys. We report three cases of lymphoblastic lymphoma, a very rare form of lymphoma, presenting with AKI and bilateral enlargement of kidneys, diagnosed by percutaneous kidney biopsy. Lymphomatous infiltration should be suspected with such clinical presentation. Kidney biopsy is a valuable diagnostic tool, to establish the correct diagnosis and subtype of lymphoma for timely initiation of therapy for these aggressive hematological malignancies.

Acute kidney injury and bilateral symmetrical enlargement of the kidneys as first presentation of B-cell lymphoblastic lymphoma

Lymphoblastic lymphoma is an uncommon subtype of lymphoid neoplasm in adults. Acute kidney injury at initial presentation due to lymphoblastic lymphoma infiltration of the kidneys has rarely been described. We report a 19-year-old woman who presented with acute kidney injury due to massive lymphomatous infiltration of the kidneys. The diagnosis of B-cell lymphoblastic lymphoma was established by immunohistochemical study of the biopsied kidney. The patient had an excellent response to the VDCLP protocol (vincristine, daunomycin, cyclophosphamide, asparaginase, and dexamethasone) with sustained remission. We recommend that lymphomatous infiltration be considered in patients presenting with unexplained acute kidney injury and enlarged kidneys.

Common and less-common renal masses and masslike conditions

As an increasing number of imaging examinations are performed, a greater number of incidental renal lesions are detected. Apart from the usual cysts and solid renal cell carcinomas, a variety of unusual benign and malignant renal lesions exist. Imaging is invaluable in characterizing these lesions and is confirmatory in some benign lesions. Renal cell carcinoma remains the diagnosis of exclusion; however, assessment of the imaging pattern in the appropriate clinical context can improve diagnostic accuracy. The objective of this article is to familiarize the radiologist with the imaging appearance of unusual non-neoplastic and neoplastic lesions and correlate with histopathologic studies when available.

Hematuria and decreased kidney function as initial signs of acute B-cell lymphoblastic leukemia

We report the case of a 14-year-old boy who presented with hematuria and decreased kidney function as initial manifestations of acute lymphoblastic leukemia (ALL). Computed tomography of the abdomen showed extensive retroperitoneal lymphadenopathy and bilateral nephromegaly. The patient's kidney biopsy specimen showed a dense monomorphous interstitial infiltrate of small round blue cells with significant nuclear atypia. Immunohistochemical workup showed positive staining for CD20, CD10, and terminal deoxynucleotidyl transferase (TdT), consistent with ALL. The patient underwent induction chemotherapy, attained remission 4 weeks after induction, and presently is stable in the consolidation phase of chemotherapy. This is an unusual case of ALL involving both kidneys with initial presenting signs of hematuria and decreased kidney function.

Isolated renal relapse in acute lymphoblastic leukemia

Current therapy for acute lymphoblastic leukemia have resulted in cure rates over 80%. Relapses occur most frequently in the bone marrow. We report the unusual case of a young man who presented with an isolated kidney relapse after maintaining remission from acute lymphoblastic leukemia for over 6 years. Sites of extramedullary relapse and a review of the literature are discussed.

Bilateral nephromegaly simulating wilms tumor: a rare initial manifestation of acute lymphoblastic leukemia

A 7-year-old boy was referred with a provisional diagnosis of bilateral Wilms tumor. Peripheral smear revealed elevated leukocyte count with 90% blasts. Bone marrow aspiration and biopsy were hypercellular with sheets of blasts. Immunohistochemistry on paraffin sections showed a pre-B phenotype of acute lymphoblastic leukemia. Computerized tomographic scan of the abdomen showed moderate bilateral renal enlargement. Ultrasound-guided fine needle aspiration cytology of both kidneys showed blasts similar to those seen in the bone marrow. Finally, a diagnosis of pre-B acute lymphoblastic leukemia infiltrating both the kidneys was made. This case is being presented because of its rarity.

Pediatric renal leukemia: spectrum of CT imaging findings

BACKGROUND

The kidneys are a site of extramedullary leukemic disease that can be readily detected by CT.

OBJECTIVE

To demonstrate the spectrum of CT findings in children with renal leukemic involvement.

MATERIALS AND METHODS

Twelve children were identified retrospectively as having renal leukemic involvement by contrast-enhanced CT of the abdomen. Contrast-enhanced CT images through the kidneys of each patient were reviewed by two pediatric radiologists. Pertinent imaging findings and renal lengths were documented. The electronic medical record was accessed to obtain relevant clinical and pathologic information.

RESULTS

Five patients with renal leukemic involvement presented with multiple bilateral low-attenuation masses, while three patients demonstrated large areas of wedge-shaped and geographic low attenuation. Four other patients presented with unique imaging findings, including a solitary unilateral low-attenuation mass, solitary bilateral low-attenuation masses, multiple bilateral low-attenuation masses including unilateral large conglomerate masses, and bilateral areas of ill-defined parenchymal low attenuation. Two patients showed unilateral nephromegaly, while eight other patients showed bilateral nephromegaly. Two patients had normal size kidneys. Two patients had elevated serum creatinine concentrations at the time of imaging.

CONCLUSION

Renal leukemic involvement in children can present with a variety of CT imaging findings. Focal renal abnormalities as well as nephromegaly are frequently observed. Most commonly, renal leukemic involvement does not appear to impair renal function.

A rare case of enteropathy-associated T-cell lymphoma presenting as acute renal failure

Enteropathy-associated T-cell lymphoma (EATCL) is a high grade, pleomorphic peripheral T-cell lymphoma usually with cytotoxic phenotypes. We describe a first case of patient with EATCL that is remarkable for its fulminant course and invasion of both kidneys manifested as acute renal failure. The patient was a 23 year old woman with a long history of celiac disease. She was presented with acute renal failure and enlarged mononuclear infiltrated kidneys. Diagnosis of tubuloi-nterstitial nephritis and polyserositis was confirmed with consecutive pulse doses of steroid therapy. After reco-very, she had disseminated disease two months later. Magnetic resonance imaging showed thickened intestine wall, extremely augmented kidneys, enlarged intra-abdominal lymph nodes with extra-luminal compression of common bile duct. Laparotomy with mesenterial adipous tissue and lymph glands biopsy was done. Consecutive pathophysiological and immunohistochemical analyses confirmed the diagnosis of EATCL: CD45RO+, CD43+, CD3+. The revision of renal pathophysiology sub-stantiated the diagnosis. The patient received chemotherapy, but unfortunately she died manifesting signs of pulmonary embolism caused by tumor cells.