Mycosis fungoides with focal CD 30 transformation in an adolescent

Is immunohistochemical expression of GATA3 helpful in the differential diagnosis of transformed mycosis fungoides and primary cutaneous CD30-positive T cell lymphoproliferative disorders?

Mycosis fungoides with large cell transformation (MFLCT) can be difficult to distinguish from primary cutaneous CD30+ T cell lymphoproliferative disorders (PC CD30+ LPD), especially primary cutaneous anaplastic large cell lymphoma (PC-ALCL). This diagnostic distinction is critical for appropriate patient management. GATA3 has been proposed to be useful in the discrimination between these two entities. We identified 25 cases of MFLCT and 24 cases of PC CD30+ LPDs (including lymphomatoid papulosis (n=14), PC-ALCL (n=6), and CD30+ LPD, not otherwise specified (n=4)) diagnosed at our institution from 2002 to 2019. Sections from archived specimens were stained to evaluate for GATA3 expression by immunohistochemistry and compared among cutaneous CD30+ T cell LPDs. The majority of the MFLCT cohort had strong, diffuse expression of GATA3 ranging from 0 to 100% of dermal T cells (mean 53.20%) with 15/25 cases (60%) showing GATA3 expression greater than 50%, while the PC CD30+ LPD group showed variable, moderate GATA3 labeling ranging from 0 to 60% of dermal T cells (mean 23.26%), with 5/6 cases (83%) showing GATA3 expression less than 40% (p =0.003). The calculated sensitivity and specificity were 56% and 74%, while positive and negative predictive values were 70% and 61%, respectively. Based on the percent staining of positive cells, using 50% as a cutoff value for expression, GATA3 might be a useful immunohistochemical marker to discriminate MFLCT from PC CD30+ LPDs, including PC-ALCL.

Mycosis fungoides in pediatric patients: Clinical features, diagnostic challenges, and advances in therapeutic management

Mycosis fungoides (MF) is the most common primary cutaneous lymphoma in pediatric patients. Given the indolent nature of MF, symptoms often present in childhood but may not be diagnosed as MF until adulthood. Delayed diagnosis is associated with poor long-term prognosis. Thus, increased clinician recognition and accurate diagnosis of early-stage MF in pediatric patients is critically important. In this review, we summarize the clinical features of the most common pediatric MF subtypes and highlight important differences between pediatric and adult MF. Moreover, we reviewed all pediatric MF case series published between 2008 and 2018 to analyze treatment modalities and identify emerging therapies. As treatment of pediatric MF is complex, selection of therapy varies significantly depending upon the specific clinical characteristics, disease severity, and patients' preferences.

Cutaneous Hematolymphoid and Histiocytic Proliferations in Children

This article focuses on cutaneous hematopoietic neoplasms that are more likely to be encountered in the pediatric age-group and includes both lymphoproliferative and histiocytic disorders. The cutaneous hematologic disorders in children have a different epidemiologic profile to what is seen during adulthood. Although mycosis fungoides is the most frequent form of cutaneous lymphoma in adults, it is very rare in children. Because lymphoblastic leukemias and lymphomas are more frequent in the pediatric setting, cutaneous leukemic infiltrates are relatively common in this age-group. Similarly, histiocytic disorders are more common in children, particularly Langerhans cell histiocytosis and juvenile xanthogranuloma. Notably, the histiocytic disorders have undergone significant modifications on their nomenclature in the basis of the molecular characteristics that are present in them. A summary of the most frequent cutaneous hematopoietic disorders in children will be discussed further in this review.

Juvenile mycosis fungoides with large-cell transformation: Successful treatment with psoralen with ultraviolet A light, interferon-alfa, and localized radiation

Mycosis fungoides with large-cell transformation is historically associated with a poor prognosis. Pediatric cases of mycosis fungoides with large-cell transformation are rare, with only three other cases reported in the literature. We present the first case of a child with almost complete remission of his mycosis fungoides with large-cell transformation shortly after administration of psoralen plus ultraviolet A, interferon-alfa, and localized radiation.