Clinical, haematological, and radiological features in T-cell lymphoblastic malignancy in childhood

Evaluation of Chest Radiographs of Children with Newly Diagnosed Acute Lymphoblastic Leukemia

OBJECTIVE

To evaluate the diagnostic yield of baseline chest radiographs (CXRs) of children with acute lymphoblastic leukemia (ALL).

STUDY DESIGN

We reviewed the CXR findings at diagnosis for 990 patients aged 1-18 years with ALL treated during the Total XV and XVI studies at St. Jude Children's Research Hospital and evaluated the associations of these findings with clinical characteristics and initial management.

RESULTS

Common findings were peribronchial/perihilar thickening (n = 187 [19.0%]), pulmonary opacity/infiltrate (n = 159 [16.1%]), pleural effusion/thickening (n = 109 [11.1%]), mediastinal mass (n = 107 [10.9%]), and cardiomegaly (n = 68 [6.9%]). Portable CXRs provided results comparable with those obtained with 2-view films. Forty of 107 patients with a mediastinal mass (37.4%) had tracheal deviation/compression. Mediastinal mass, pleural effusion/thickening, and tracheal deviation/compression were more often associated with T-cell ALL than with B-cell ALL (P < .001 for all). Pulmonary opacity/infiltrate was associated with younger age (P = .003) and was more common in T-cell ALL than in B-cell ALL (P = .001). Peribronchial/perihilar thickening was associated with younger age (P < .001) and with positive central nervous system disease (P = .012). Patients with cardiomegaly were younger (P = .031), more often black than white (P = .007), and more often categorized as low risk than standard/high risk (P = .017). Patients with a mediastinal mass, pleural effusion/thickening, tracheal deviation/compression, or pulmonary opacity/infiltrate were more likely to receive less invasive sedation and more intensive care unit admissions and respiratory support (P ≤ .001 for all). Cardiomegaly was associated with intensive care unit admission (P = .008). No patients died of cardiorespiratory events during the initial 7 days of management.

CONCLUSIONS

The CXR can detect various intrathoracic lesions and is helpful in planning initial management.

Paediatric lymphoblastic T-cell leukaemia and lymphoma: one or two diseases?

There is ongoing discussion on whether paediatric acute T-cell lymphoblastic leukaemia (T-ALL) and paediatric lymphoblastic T-cell lymphoma (T-LBL) are two distinct entities or whether they represent two variant manifestations of one and the same disease and the distinction is arbitrary. Both show overlapping clinical, morphological and immunophenotypic features. Many clinical trials use the amount of blast infiltration of the bone marrow as the sole criterion to distinguish between T-ALL and T-LBL. The current World Health Organization classification designates both malignancies as T lymphoblastic leukaemia/lymphoma. However, subtle immunophenotypic, molecular and cytogenetic differences suggest that T-ALL and T-LBL might be biologically different in certain aspects. The current review summarizes and discusses the recent advances and understanding of the molecular profile of paediatric T-ALL and T-LBL.

Lateral position prevents respiratory occlusion during surgical procedure under general anesthesia in the patient of huge anterior mediastinal lymphoblastic lymphoma

Lymphoblastic lymphoma, an aggressive mediastinal mass, is recognized as serious threat to the patient in developing cardiac tamponade or airway obstruction. Surgical procedure is often required to relieve clinical emergency and to establish prompt pathological diagnosis. However, in such a patient, acute respiratory occlusion in the spine position can be a life-threatening complication during general anesthesia. We describe a 17-year-old man whose cardiac tamponade was treated by pericardial-pleural window through a left anterior thoracotomy in the lateral position. The patient recovered from hemodynamic compromise without showing respiratory occlusion during general anesthesia and remained in the lateral position until extubation. Pathological diagnosis was precursor T-lymphoblastic lymphoma. There were no complications attributable to the operative procedure. Further chemotherapy reduced the mediastinal mass in size after two weeks when the patient developed sepsis and died. Lateral position prevents respiratory occlusion during surgical procedure under general anesthesia in the patient of huge anterior mediastinal tumor with airway obstruction.

Two Entities of Precursor T-Cell Lymphoblastic Leukemia/Lymphoma Based on Radiologic and Immunophenotypic Findings

Precursor T-cell lymphoblastic leukemia/lymphoma (T-ALL/LBL) presents a mediastinal mass in one half of cases. Although the immunophenotypic features of T-ALL/LBL have been analyzed in several studies, few studies have been focused on the relationship between the anatomic distribution of lesions and immunophenotypic findings. We analyzed the clinicopathologic findings for 17 patients with T-ALL/LBL diagnosed since 1993 and whose radiologic findings were available. Data on 14 men and 3 women with a median age of 26 years (range, 10-61 years) were analyzed. On the basis of radiologic findings, the cases were divided into thymic type (n = 8) and nonthymic type (n = 9). Patients with the thymic type of T-ALL/LBL had a large mediastinal mass and minimal systemic lymphadenopathy only in the supradiaphragmatic region. Those with the non-thymic type had predominantly systemic lymphadenopathy that included infradiaphragmatic lesions. Expression of CD8 (6/7 versus 0/9) was more frequently found in the thymic type (P < .001), whereas expression of CD56 (0/7 versus 5/9) was more frequent in the nonthymic type (P = .034). In conclusion, T-ALL/LBL was divided into 2 entities, thymic type and nonthymic type, on the basis of radiologic findings and immunophenotypic features. Analysis of the expression of CD8 and CD56 would be useful for biologically classifying T-ALL/LBL into the 2 types. This study was performed in a single institution, was retrospective, and had a limited number of patients; multicenter confirmatory studies are warranted.

Lymphomatous presentation of childhood acute lymphoblastic leukemia. A subgroup at high risk of early treatment failure

Multivariate analyses of the clinical course of 1537 children with acute lymphoblastic leukemia (ALL) identified a subgroup which experienced short remission duration and a high incidence of extramedullary relapse. The patients differed from other ALL patients by the presence at diagnosis of two or more of a constellation of clinical and laboratory features: organomegaly or mass disease, E-rosette positivity, hemoglobin level greater than 10 g/dl, leukocyte count greater than 50,000/microliters, male predominance, and older age. This type of presentation of ALL is referred to as the "lymphoma syndrome" (LS) since such patients exhibit a pattern of several clinical and laboratory features which were observed repeatedly but in differing combinations, and some of which clinically resemble lymphoma. A subsequent database from 2231 patients was analyzed. Patients with a mediastinal mass, massive splenomegaly, or massive adenopathy, alone or in combination, had a worse outcome when the patient also had either leukocytosis, E-rosette-positive lymphoblasts, or a normal or near normal hemoglobin (Hb) level at diagnosis. Similarly, the above three laboratory features alone or in combination did not predict less than 40% disease-free survival (DFS) unless they were accompanied by at least one of the clinical features of mass disease. When at least one clinical feature and at least one laboratory feature were present, the overall DFS was 36% 6 years after diagnosis versus 64% for all other patients. The association of these features with poor prognosis remained significant after adjusting for the level of leukocyte count at diagnosis, age at diagnosis, and sex of the patients. Patients with this recurrent syndrome of features do not represent a homogeneous biologic entity but they constitute a subgroup of patients with ALL having a high risk of treatment failure using current therapies, including failure to achieve remission, early relapse, and increased frequency of relapse in extramedullary sites. They deserve early recognition at diagnosis and selection of treatment strategies appropriate for very high risk ALL.

Mediastinal mass and tracheal obstruction during general anesthesia

A 24-year-old man had a large anterior mediastinal mass and a nonproductive cough of 6 weeks' duration. With the patient under general anesthesia, a diagnostic mediastinoscopy was performed with endotracheal intubation. During the procedure, acute respiratory failure developed as a result of tracheal obstruction. Fiberoptic bronchoscopic examination of the patient in the supine position revealed almost total extrinsic compression of the trachea and no evidence of intraluminal disease. Reexamination of the trachea with the patient in sitting and semiprone positions showed resolution of the extrinsic compression and respiratory distress. Flow-volume curves obtained before treatment of the mediastinal mass (histologically diagnosed as Hodgkin's lymphoma) disclosed major airway compression with the patient in the supine position; the abnormality disappeared after chemotherapy. The mechanisms responsible for tracheal compression by mediastinal masses during general anesthesia may include the following: (1) the effect of anesthesia on pulmonary mechanics, (2) the supine body position, (3) the elimination of glottic regulation of airflow by endotracheal intubation, (4) changes related to the surgical manipulation of the tumor itself, (5) the size and location of the mediastinal mass, (6) the young age of the patient, and (7) preexisting airways disease. Anticipation and prevention of potential respiratory complications and preparedness to treat them appropriately are important aspects of the management of these patients.