Two children with extra-nodal Mycobacterium avium complex infection.

Mycobacterium avium complex (MAC) is usually considered an opportunistic organism, which infects immunocompromised children or those with structural airway abnormalities. We present two cases of MAC infection affecting immune competent children, likely from hot tubs with primary involvement of pulmonary and urinary systems. These cases highlight the importance of asking about hot tub use in immune competent children with suspected or confirmed MAC infections.

CD30-positive lymphomatous (nonleukemic) variant of adult T-cell leukemia/lymphoma, HTLV-1 associated.

Nonleukemic variant of HTLV-1-associated adult T-cell leukemia lymphoma (ATLL) is a rare variant, and herein, we describe a case with strong and diffuse positivity of neoplastic cells for CD30. Even though ATLL is aggressive entity with poor prognosis, in our case, there was very good clinical response achieved with brentuximab-containing regimen. Therefore, HTLV-1-associated ATLL can be included in the differential diagnostic approach of CD30-positive lymphoproliferative disorders.

Primary pulmonary/pleural melanoma in a 13 year-old presenting as pleural effusion.

Melanoma in children, adolescents, and young adults is uncommon and reported almost exclusively as cutaneous melanoma. Melanoma presenting as a pleural effusion is very rare in adults and not reported in the pediatric population. Additionally, primary pulmonary melanoma is overall very rare and undocumented in pediatric patients. Furthermore, the distinction between a primary pulmonary/pleural melanoma versus a regressed cutaneous melanoma with pulmonary/pleural metastases remains extremely challenging. We discuss a case of a previously healthy 13-year-old girl that presented with a left-sided pleural effusion. Investigations revealed a large mediastinal mass, left-sided pleural and pulmonary nodules, a sacral mass, and bone marrow infiltration. The neoplasm was subsequently diagnosed by morphology and immunocytochemistry with histological correlation as malignant melanoma. As no mucosal, eye, or cutaneous lesions were identified, we deliberate the likelihood of a regressed cutaneous melanoma with metastases versus primary pulmonary/pleural melanoma with pleural effusion and discuss its diagnostic approach.

Cancer stem cells: a review of potential clinical applications.

CONTEXT: Cancer stem cells (CSCs) comprise a minor cell population in a tumor; however, they possess self-renewal capacity and are responsible for tumor recurrence and the emerging issue of tumor resistance. Despite recent advances in the study of pathogenesis and mechanisms of CSC-mediated disease recurrence and multidrug resistance, many questions remain unanswered. OBJECTIVES: To provide an overview of CSC theory and to describe major methods of CSC detection and isolation, with the emphasis on those techniques that are potentially relevant in clinical laboratory practice. Particular attention is given to CSC markers, such as cancer testis antigens, which could become promising targets in the development of immunotherapy in settings of minimal residual disease. DATA SOURCES: The review is based on analysis of peer-reviewed literature cited in PubMed, as well as preliminary results of studies conducted in our laboratory. CONCLUSIONS: Despite a lack of consensus in the scientific community on research methodology, CSCs have demonstrated significant potential as therapeutic targets in the treatment of cancer. Further research of CSC biology and markers will eventually lead to the development of novel therapeutic approaches for targeting these cells to treat resistant and recurrent tumors and minimal residual disease.

Hashimoto encephalopathy with fulminant myocarditis.

There are very limited data concerning the association of lymphocytic thyroiditis with cardiomyopathy, and there is only one published report of fatal cardiomyopathy associated with autoimmune thyroiditis. An association of Hashimoto encephalopathy (HE) with autoimmune myocarditis has not yet been reported. Here we describe a case of a 31-year-old man with autoimmune thyroiditis complicated by HE, who succumbed to autoimmune myocarditis. This association raises the possibility that HE and myocarditis may share a common pathogenetic mechanism in some cases.

Primary pancreatic sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease): an unusual extranodal manifestation clinically simulating malignancy.

Abstract Sinus histiocytosis with massive lymphadenopathy (SHML), also called Rosai-Dorfman disease, is a rare entity. Its etiology and pathogenesis are still essentially unclear. The histologic hallmark of this disease is proliferation of distinctive histiocytes within lymph node sinuses and in extranodal sites. Approximately 23% of patients with SHML, documented in the SHML Registry, presented with disease primarily in extranodal sites, and very few cases of SHML (<1%) involving the gastrointestinal system have been described in the literature. We report an unusual case of primary pancreatic SHML with infiltration of the process into peripancreatic, perinephric, and perisplenic adipose tissue, simulating malignancy.