Large cell morphology, CMYC+ tumour cells, and PD-1+ tumour cell/intense PD-L1+ cell reactions are important prognostic factors in nodal peripheral T-cell lymphomas with T follicular helper markers.

BACKGROUND: The clinicopathological characteristics and prognostic factors in nodal peripheral T-cell lymphomas (PTCLs) with two or more T follicular helper markers (TFH+) are not adequately investigated. METHODS: Immunohistologically, we selected 22 patients with TFH+ lymphoma (PTCL-TFH) in 47 of PTCL-not otherwise specified (NOS), and subclassified into large and small cell groups. We compared the two groups with 39 angioimmunoblastic T-cell lymphoma (AITL) and seven follicular T-cell lymphoma (F-TCL) patients. Prognostic factors were analysed by overall survival in patients with three types of TFH+ PTCLs. RESULTS: Thirteen large cell and nine small cell PTCL-TFH patients had more than two TFH markers including programmed cell death-1 (PD-1). Large cell PTCL-TFH showed frequent CMYC expression in 10 patients (77%), and four of 11 large cell group (36%) had somatic RHOA G17V gene mutation by Sanger sequencing. Large cell PTCL-TFH patients showed significantly worse prognosis than those of the small cell group, AITL, and F-TCL (p < 0.05). In TFH+ PTCLs, CMYC+ tumour cells, and combined PD-1 ligand 1 (PD-L1) + tumour cells and intense reaction of PD-L1+ non-neoplastic cells (high PD-L1+ cell group) were significantly poor prognostic factors (p < 0.05). Combinations of CMYC+ or PD-1+ tumour cells and high PD-L1+ cell group indicated significantly poor prognosis (p < 0.01). CONCLUSION: Large cell PTCL-TFH indicated poor prognosis in TFH+ PTCLs. These data suggested that CMYC+ tumour cells and intense PD-L1+ cell reaction influenced tumour cell progression in TFH+ PTCLs, and PD-1+ tumour cell/intense PD-L1+ cell reactions may play a role in immune evasion.

[A case of intravascular malignant lymphomatosis presenting with epicornus syndrome and diagnosed by bone marrow biopsy].

A-46-year-old woman admitted to our hospital because of numbness of bilateral lower limbs and urinary incontinence. The initial neurological examination showed sensory impairment below S1 level with urinary incontinence, indicating epicornus syndrome. Spinal MR imaging demonstrated unremarkable on conventional and enhanced images with Gd-DTPA. Cerebrospinal fluid examination revealed slightly elevated protein level without pleocytosis. Thereafter, subacute ascending myelopathy including flaccid paraparesis and urinary retention, developed. Because the patient had low grade fever, fatigue, weight loss and elevated serum soluble IL-2 receptor and LDH titers, we investigated her for lymphoma. Although lymphadenopathy or mass lesions were not found on whole-body CT scan, bone marrow biopsy showed the presence of inravascular large B-cell lymphoma (IVL). Thus the patient's progressive myelopathy was probably caused by IVL invasion. Ten days after the initiation of chemotherapy, her neurological symptoms transiently improved; however, her paraparesis and urinary incontinence gradually worsened thereafter, despite of treatment. IVL often presents with neurological manifestations, including myelopathy. There have been a few reports of IVL presenting with lower lumbar spinal cord and conus medullaris. It should be noted that IVL can cause unidentified progressive ascending myelopathy without positive MRI findings.

Mitochondria are more numerous and smaller in pink-eyed dilution melanoblasts and melanocytes than in wild-type melanocytes in the neonatal mouse epidermis.

Abstract The mouse pink-eyed dilution (p) locus is known to control the melanin content in melanocytes. However, it was not known whether the p gene is involved in regulating the proliferation and differentation of melanocytes during development, especially the biogenesis of melanosomes and other organelles. Epidermal cell suspensions of neonatal dorsal skin derived from mice wild type for the p locus (black, C57BL/10JHir-P/P) and their congenic mutant phenotype (pink-eyed dilution, C57BL/10JHir-p/p) were cultured in serum-free melanocyte-proliferation medium (MDMD). The supplement of additional L-tyrosine (Tyr) into the MDMD stimulated the differentiation of p/p melanoblasts into melanocytes. Electron microscopy revealed that in p/p melanoblasts and melanocytes treated with L-Tyr, the number of stage II and III melanosomes dramatically increased. Moreover, p/p melanoblasts possessed smaller but more numerous mitochondria than P/P melanocytes. The treatment of p/p melanoblasts and melanocytes with L-Tyr decreased the number of mitochondria. The supplement of 2, 4-dinitrophenol (DNP), an inhibitor of mitochondrial function, into the MDMD stimulated both the proliferation and differentiation of p/p melanoblasts. Simultaneous treatment of DNP and L-Tyr dramatically stimulated the differetiation of p/p melanocytes. These results suggest that L-Tyr and some unknown factors related to mitochondrial function may influence the differentiation of melanoblasts in the epidermis of p/p mice.