[Application of digital pathology tools. An unusual case of non-Hodgkin lymphoma].

Currently, lymphoma diagnosis is based on a combination of morphology, immunophenotyping, and molecular testing. Using the example of an unusual case of malignant non-Hodgkin lymphoma, we show that improved visualization using digital pathology contributes to the convergence of these complementary diagnostic modalities. A 45-year-old woman presented with skin rash and cervical lymphadenopathy.

Isolated B-cell lymphoproliferative disorder at the dura mater with B-cell chronic lymphocytic leukemia immunophenotype.

Lymphoma manifestations of the dura mater are extremely rare and have mostly been attributed to extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) type. We report a patient with an isolated meningeal tumor, identified as a B-cell lymphoproliferative disorder with typical B-cell chronic lymphocytic leukemia immunophenotype. Because of the subclinical detection of trisomy 3 in the bone marrow by cytogenetic analysis and interphase fluorescence in situ hybridization, CD5(+) MALT is an important differential diagnosis; however, to our knowledge, this entity has never been reported in the context of dural lymphoma.

Use of oxytocin receptor expression in distinguishing between uterine smooth muscle tumors and endometrial stromal sarcoma.

The present study aimed to investigate oxytocin receptor (OTR) expression in the normal uterus, and particularly in uterine smooth muscle tumors and endometrial stromal sarcomas (ESSs) because these tumors can be difficult to distinguish. The expressions of OTR, CD10, h-caldesmon, calponin, smooth muscle actin, and desmin were analyzed in 10 conventional leiomyomas (LMs), 10 highly cellular leiomyomas (HCLs), eight leiomyosarcomas (LMSs), and nine ESSs. In five normal uteri and five cases of adenomyosis, OTR was strongly expressed in the myometrium and showed expression pronounced in the surface epithelium during the late proliferative phase and at the time of ovulation, whereas the endometrial stromal cells were negative.

Quality assurance in immunohistochemistry: results of an interlaboratory trial involving 172 pathologists.

The practicability of quality assurance in immunohistochemistry and its integration into the diagnostic process were both tested in this Germany-wide interlaboratory trial. One hundred seventy-two pathologists received one hematoxylin and eosin and five unstained slides from five cases; all cases were selected by a panel because immunohistochemistry was required for their final diagnosis. Participants rendered a morphologic diagnosis and then substantiated it immunohistochemically.

[Marginal zone lymphomas: extranodal MALT type, nodal and splenic].

Marginal zone B-cell lymphomas (MCL) of extranodal, nodal and splenic origin appear to be different lymphoma entities with a similar growth pattern in the marginal zone of the B-follicles. Decisive for the detection of MCL as a distinct lymphoma entity was the "MALT concept" for lymphoid infiltrates in the gastric and intestinal mucosa as described by Isaacson et al. in the 1980's.