γδ T-Cell Acute Lymphoblastic Leukemia/Lymphoma: Discussion of Two Pediatric Cases and Its Distinction from Other Mature γδ T-Cell Malignancies.

Gamma delta (γδ) T-cell antigen receptor (TCR) expression and its related T-cell differentiation are not commonly reported in T-cell acute lymphoblastic leukemia/lymphoma (T-ALL). Here we report two pediatric T-ALL cases and present their clinical features, histology, immunophenotypes, cytogenetics, and molecular diagnostic findings. The first patient is a two-year-old girl with leukocytosis, circulating lymphoblasts, and a cryptic insertion of a short-arm segment at 10p12 into the long-arm segment of 11q23 resulting in an MLL and AF10 fusion transcript, which may be the first reported in γδ T-ALL. She responded to the chemotherapy protocol poorly and had persistent diseases. Following an allogeneic bone marrow transplant, she went into remission. The second patient is an eleven-year-old boy with a normal white cell count, circulating blasts, and a normal karyotype, but without any immature cellular markers by flow cytometric analysis. He responded to the chemotherapy well and achieved a complete remission. These cases demonstrate the diverse phenotypic, cytogenetic, and molecular aspects of γδ T-ALL. Early T-precursor- (ETP-) ALL and their differential diagnosis from other mature γδ T-cell leukemia/lymphomas are also discussed.

ATYPICAL HEMOLYTIC UREMIC SYNDROME IN AN ADULT SUCCESSFULLY TREATED WITH ECULIZUMAB.

Atypical Hemolytic Uremic Syndrome is a triad of microangiopathic hemolytic anemia, thrombocytopenia and acute renal failure not associated with diarrhea. It is a rare condition associated with complement disorders in about 50 percent of cases. The first line of treatment is therapeutic plasma exchange. However, because clinical response to TPE varies, an anti-complement drug, eculizumab has been tried. We report a case of atypical HUS successfully treated with eculizumab.

Maximizing the diagnostic yield from bone marrow aspirate material using the cell block technique on clot sections.

BACKGROUND: Paraffin section of bone-marrow aspirate (clot section) is one of several components of bone marrow biopsy. Improper acquisition of aspirate material results in lack of diagnostic tissue and a waste of resources. OBJECTIVE: To detail a novel cell block method of aspirated marrow as a way to ensure maximum yield. This is of particular value when the material gathered via core biopsy is inadequate. METHOD: We used the cell block method to evaluate paraffin-embedded sections of hematopoietic tissue from bone marrow aspirate. RESULTS: The range of diagnoses possible from an adequate clot section parallels those from a comparable core biopsy. Examples of an adequate clot section include lesions assessed by routine hematoxylin-eosin (H&E) staining, special and immunohistochemistry (IHC) stains, and molecular diagnostic studies such as fluorescent in situ hybridization (FISH) and polymerase chain reaction (PCR). CONCLUSION: A bone marrow clot section comprised of sinusoidal blood is inadequate for morphological interpretation and is a waste of resources. Hence, we recommend the cell block technique for procurement; this method ensures maximum capture of material needed to establish a diagnosis.

Oligosecretory biclonal multiple myeloma.

Among the plasma cell dyscrasias, non-secretory myeloma is one of the rarest. This diagnosis is based on the absence of monoclonal proteins in the serum and urine. When serum free light chains are trace and the kappa: lambda ratio normal, clonality may however be established by PCR. We present a case of an oligosecretory myeloma confirmed by PCR, which would have hitherto been classified as non-secretory.

Large cell lymphoma associated with prosthetic joint debris.

Soft tissue reactions to materials in joint prostheses include discoloration, fibrosis, florid histiocytic reaction, and granulomatous inflammation with foreign body giant cell reaction. Clinical manifestations include pain and swelling. We report a case of temporomandibular joint Proplast-Teflon prosthesis, followed by the development of large cell lymphoma in the left parotid gland 10 years after joint replacement. While it is unclear whether the implant directly contributed to the development of lymphoma, this association has not been previously documented, prompting this report.