A pediatric translational perspective on the entity "progressive transformation of germinal centers (PTGC)"

How I approach: The workup and management of patients with progressive transformation of the germinal center

Progressive transformation of the germinal center (PTGC) is a common and underrecognized cause of pediatric lymphadenopathy. PTGC may be associated with numerous systemic medical conditions that require further workup and management, including malignancy, autoimmune conditions, lymphoproliferative conditions, immunodeficiency, and infection. Given the breadth and rarity of the associated conditions, workup should be tailored to the individual patient and occur in a tiered approach. Patients with PTGC require ongoing follow-up, given their long-term risk of malignancy and recurrent PTGC.

Chronic Generalized Lymphadenopathy in a Child—Progressive Transformation of Germinal Centers (PTGC)

Background: Enlarged lymph nodes are a common complaint in a Pediatrician’s office. Diagnosis of reactive lymphadenopathy secondary to infectious, inflammatory, immune dysregulation calls for clinical investigation, including a thorough history, physical exam, imaging, and less often, a biopsy of the lymph node. Here we discuss a rare presentation of extensive generalized, chronic, waxing, and waning lymphadenopathy diagnosed as Progressive Transformation of Germinal Centers (PTGC) and the course of illness over eight years follow up period. Discussion: Progressive Transformation of Germinal Centers (PTGC) is considered a benign condition, but extensive recurrent generalized lymphadenopathy in a very young child has not been reported before. This case demonstrates the importance of long-term follow-up and tailoring the diagnostic work-up and management based on new signs and symptoms. Here we focus on the clinical considerations and management of complex presentation of a common clinical finding.

Update on Pediatric and Young Adult Mature Lymphomas

After acute leukemia and brain and central nervous system tumors, mature lymphomas represent the third most common cancer in pediatric patients. Non-Hodgkin lymphoma accounts for approximately 60% of lymphoma diagnoses in children, with the remainder representing Hodgkin lymphoma. Among non-Hodgkin lymphomas in pediatric patients, aggressive lymphomas, such as Burkitt lymphoma, diffuse large B-cell lymphoma, and anaplastic large cell lymphoma, predominate. This article summarizes the epidemiologic, histopathologic, and molecular features of selected mature systemic B-cell and T-cell lymphomas encountered in this age group.

Progressive Transformation of Germinal Centers: Single-Center Experience of 33 Turkish Patients

Progressive transformation of germinal centers (PTGCs) is a benign disease of the lymph nodes that is rarely associated with Hodgkin disease. We reviewed the clinical and pathologic features of PTGCs and the relationship of PTGCs with lymphoid neoplasia in an adult population. The data from 33 patients who were diagnosed with PTCGs were retrospectively analyzed. Of the 33 PTGC patients, 48.5% were men and 51.5% were women, with a mean age of 43.8 years at diagnosis. Most of the enlarged and excised lymph nodes were cervical and axillary. Diffuse large B-cell lymphoma and nodular lymphocyte predominant Hodgkin lymphoma was detected concurrent with PTGC in 2 patients. Also, PTGCs was detected 3 years after the diagnosis of diffuse large B-cell lymphoma, nodular lymphocyte predominant Hodgkin lymphoma, and T-cell-rich B-cell lymphoma in 3 patients. No relapse was found in the patients with lymphoma, and no progression to lymphoma was detected during the follow-up of the other patients. PTGCs is not considered a premalignant entity; however, the development of lymphoma has been reported rarely. If PTGCs occurs in the follow-up process of patients with lymphoma, the follow-up intervals should be shortened.

Micronodular thymic neoplasms: case series and literature review with emphasis on the spectrum of differentiation

We report nine cases of micronodular thymoma with lymphoid B-cell hyperplasia and one case of micronodular thymic carcinoma with lymphoid hyperplasia from our institution. For a better understanding of these rare tumors, clinical records, and histological features of these cases were reviewed, with detailed review of additional 64 literature cases of micronodular thymic neoplasms. The joint analysis identified 64 cases of micronodular thymoma with lymphoid B-cell hyperplasia and 9 cases of micronodular thymic carcinoma with lymphoid hyperplasia. Both groups revealed slight male predilection, with male:female ratio of 1.3:1 and 5:4, and occurred at >40 years of age, with a mean of 64 (41-83) and 62 (42-78) years, respectively. Myasthenia gravis was noted in 3/64 (5%) and 1/9 (11%) patients, respectively. Other systemic, disimmune, or hematologic disorders were noted in 6/64 (9%) and 1/9 (11%) patients, respectively. Components of conventional thymoma were reported in 11/64 (17%) micronodular thymomas with lymphoid B-cell hyperplasia, with transitional morphology between the two components in most of them. Cellular morphology was predominantly spindle in micronodular thymoma with lymphoid B-cell hyperplasia when specified (30/43), and epithelioid in micronodular thymic carcinoma with lymphoid hyperplasia (6/9), and cytological atypia was more encountered in the latter. Dedifferentiation/transformation from micronodular thymoma with lymphoid B-cell hyperplasia to micronodular thymic carcinoma with lymphoid hyperplasia seems to occur in a small subset of cases. Three cases of micronodular thymomas with lymphoid B-cell hyperplasia were described with co-existent low-grade B-cell lymphomas. Follow-up data were available for 30 micronodular thymomas with lymphoid B-cell hyperplasia and 6 micronodular thymic carcinomas with lymphoid hyperplasia, with a mean of 47 (0.2-180) months and 23 (3-39) months, respectively. Patients were alive without disease, except for five micronodular thymoma with lymphoid B-cell hyperplasia patients (dead from unrelated causes), and one micronodular thymic carcinoma with lymphoid hyperplasia patient (dead of disease).

Poor chemotherapy-induced nausea and vomiting control in children receiving intermediate or high dose methotrexate

PURPOSE

Chemotherapy emetogenicity is the most important known determinant of chemotherapy-induced vomiting (CIV) in children. However, direct evidence regarding the emetogenic potential of chemotherapeutic agents in children is limited. This study describes the prevalence of complete control of acute and delayed phase chemotherapy-induced nausea and vomiting (CINV) in children receiving methotrexate. The prevalence of anticipatory CINV is described, and risk factors for CINV are explored.

METHODS

English-speaking children (4 to 18 years) receiving intermediate-dose (ID-MTX: >1 to <12 g/m(2)/dose) or high-dose methotrexate (HD-MTX: ≥12 g/m(2)/dose) participated in this prospective study. Emetic episodes, nausea severity, and antiemetic administration were documented for 24 h from the start of the methotrexate infusion (acute phase) and for up to a further 168 h (delayed phase). CINV prophylaxis was provided at the discretion of the treating physician. Anticipatory CINV was assessed in the 24 h preceding chemotherapy. Complete CINV control was defined as no emetic episodes and no nausea.

RESULTS

Thirty children (mean age, 11.8 ± 4 years; ID-MTX, 20; HD-MTX, 10) completed the study. CINV prophylaxis included the following: ondansetron/granisetron plus dexamethasone or nabilone. Few patients experienced complete CINV control (ID-MTX: acute phase 20%, delayed phase 5%; HD-MTX: acute phase 0%, delayed phase 30%). Complete emesis control was higher (ID-MTX: acute phase 70%, delayed phase 50%; HD-MTX: acute phase 70%, delayed phase 60%). Anticipatory CINV was reported by 6/28 patients (21%). Patient age, sex, and history of motion sickness were not significant predictors of CINV.

CONCLUSIONS

The poor complete CINV control rate in children receiving methotrexate confirms the classification of HD-MTX as highly emetogenic chemotherapy (HEC) and suggests that ID-MTX be reclassified as HEC.