[Molecular pathology of tuberculosis : Status, methodology, and limits]. / Molekularpathologie der Tuberkulose : Stellenwert, Methodik und Grenzen.

In the diagnosis of mycobacterioses, microbiological examination with culture and antibiogram, possibly in combination with molecular biological testing of the fresh material, still represents the gold standard. However, these methods are not available for formalin-fixed paraffin-embedded (FFPE) material or other fixed samples. For this reason, the first step in pathology is to attempt microscopic pathogen detection (ZN/Fite/rhodamine-auramine). Subsequently, molecular pathological examination for the detection of mycobacterial gene sequences should also be considered mandatory today. Although this has clear limits due to the material, it is nevertheless well suited, if carried out correctly, to detect a mycobacterial infection or make it unlikely. A negative result may favor an alternative diagnosis but does not completely rule out mycobacteriosis.For the therapy of tuberculosis or nontuberculous mycobacterial (NTM) disease, the reliable detection of the species and the determination of resistance is of utmost importance. With regard to therapy, the clinician cannot afford to make a false diagnosis. In case of doubt, a rebiopsy for sampling native material, particularly for microbiological testing, should be discussed.

Comparison of PD-L1 expression between paired cytologic and histologic specimens from non-small cell lung cancer patients.

Expression of programmed death ligand 1 assessed on histologic samples is a confirmed predictive biomarker for anti-PD-1 immunotherapy, but its evaluation is not approved for immunocytochemistry. We investigated if PD-L1 expression shows comparable results on paired cytologic and histologic tumor specimens and interobserver variability. Percentage of PD-L1-positive tumor cells of 247 paired samples of non-small cell lung cancer was evaluated by three independent investigators. Samples were compared on the basis of the continuous values and also categorized with the tumor proportion score (TPS). Concordance was defined if continuous values were both within a deviation of 10% and if categorized values were identically grouped. Interobserver variability was assessed by the standard deviation of the mean. Based on continuous values between paired samples, perfect concordance rate was approximately 53%. With categorization of PD-L1 expression based on TPS, category was identical in 74.1%. However, defining the continuous values of PD-L1 expression between paired samples within a deviation of 10% as concordant, concordance rate was 82%. Interobserver variability was significantly higher in evaluation of cytologic specimens. Evaluation of PD-L1 expression in paired histologic and cytologic tumor specimens shows comparable results if a deviation of 10% between the values is tolerated. Interobserver variability demonstrates a much more challenging interpretation of PD-L1 expression for cytologic samples.

Improved diagnostics targeting c-MET in non-small cell lung cancer: expression, amplification and activation?

BACKGROUND: Several c-MET targeting inhibitory molecules have already shown promising results in the treatment of patients with Non-small Cell Lung Cancer (NSCLC). Combination of EGFR- and c-MET-specific molecules may overcome EGFR tyrosine kinase inhibitor (TKI) resistance. The aim of this study was to allow for the identification of patients who might benefit from TKI treatments targeting MET and to narrow in on the diagnostic assessment of MET. METHODS: 222 tumor tissues of patients with NSCLC were analyzed concerning c-MET expression and activation in terms of phosphorylation (Y1234/1235 and Y1349) using a microarray format employing immunohistochemistry (IHC). Furthermore, protein expression and MET activation was correlated with the amplification status by Fluorescence in Situ Hybridization (FISH). RESULTS: Correlation was observed between phosphorylation of c-MET at Y1234/1235 and Y1349 (spearman correlation coefficient rs = 0.41; p < 0.0001). No significant correlation was shown between MET expression and phosphorylation (p > 0.05). c-MET gene amplification was detected in eight of 214 patients (3.7%). No significant association was observed between c-MET amplification, c-MET protein expression and phosphorylation. CONCLUSION: Our data indicate, that neither expression of c-MET nor the gene amplification status might be the best way to select patients for MET targeting therapies, since no correlation with the activation status of MET was observed. We propose to take into account analyzing the phosphorylation status of MET by IHC to select patients for MET targeting therapies. Signaling of the receptor and the activation of downstream molecules might be more crucial for the benefit of therapeutics targeting MET receptor tyrosine kinases than expression levels alone.

[Cancer-to-cancer metastasis: amelanotic melanoma into renal cell carcinoma]. / Karzinom-in-Karzinom-Metastasierung eines amelanotischen Melanoms in ein Nierenzellkarzinom.

HISTORY AND PHYSICAL FINDINGS: A 54-year old man was admitted because of motor aphasia, behavioral changes and weight loss and suffered from a widely disseminated cancer with unknown primary origin (CUP) syndrome. DIAGNOSIS: The autopsy revealed that he was affected by two malignant neoplasms simultaneously: an amelanotic malignant melanoma metastasizing into a localized renal cell carcinoma. CONCLUSION: Cancer-to-cancer metastasis is an exceedingly rare, but well documented phenomenon. This is the third reported case of a malignant melanoma as donor tumor spreading into a renal cell carcinoma. Well-vascularized and slowly growing renal tumors are typical recipients for cancer-to-cancer metastases. The amelanotic character of the melanoma exerted a special diagnostic challenge. Clinical and autopsy findings as well as the immunophenotypical features of the metastatic amelanotic melanoma (HMB-45, Melan-A/MART-1, S100) and the renal cell carcinoma are described with a review of the relevant literature.

Imaging of human brain tumor tissue by near-infrared laser coherence tomography.

INTRODUCTION: Intraoperative detection of residual tumor remains an important challenge in surgery to treat gliomas. New developments in optical techniques offer non-invasive high-resolution imaging that may integrate well into the workflow of neurosurgical operations. Using an intracranial glioma model, we have recently shown that time domain optical coherence tomography (OCT) allows discrimination of normal brain, diffusely invaded brain tissue, and solid tumor. OCT imaging allowed acquisition of 2D and 3D data arrays for multiplanar analysis of the tumor to brain interface. In this study we have analyzed biopsy specimens of human brain tumors and we present the first feasibility study of intraoperative OCT and post-image acquisition processing for non-invasive imaging of the brain and brain tumor. METHODS: We used a Sirius 713 Tomograph with a superluminescence diode emitting light at a near infrared central wavelength of 1,310 nm and a coherence length of 15 microm. The light is passed through an optical mono mode fiber to a modified OCT adapter containing a lens system with a working distance of 10 cm and an integrated pilot laser. Navigation-registered tumor biopsies were imaged ex vivo and the intraoperative site of optical tissue analysis was registered by marker acquisition using a neuronavigation system. RESULTS: Optical coherence tomography non-contact measurements of brain and brain tumor tissue produced B-scan images of 4 mm in width and 1.5-2.0 mm in depth at an axial and lateral optical resolution of 15 microm. OCT imaging demonstrated a different microstructure and characteristic signal attenuation profiles of tumor versus normal brain. Post-image acquisition processing and automated detection of the tissue to air interface was used to realign A-scans to compensate for image distortions caused by pulse- and respiration-induced movements of the target volume. Realigned images allowed monitoring of intensity changes within the scan line and facilitated selection of areas for the averaging of A-scans and the calculation of attenuation coefficients for specific regions of interest. CONCLUSION: This feasibility study has demonstrated that OCT analysis of the tissue microstructure and light attenuation characteristics discriminate normal brain, areas of tumor infiltrated brain, solid tumor, and necrosis. The working distance of the OCT adapter and the A-scan acquisition rate conceptually allows integration of the OCT applicator into the optical path of the operating microscopes. This would allow a continuous analysis of the resection plain, providing optical tomography, thereby adding a third dimension to the microscopic view and information on the light attenuation characteristics of the tissue.

A non-midline spheno-orbital encephalocele in a newborn.

Basal encephaloceles in western countries occur in 1 of every 35 000-40 000 live births; with an incidence of less than 10% they are the least common of all encephaloceles. Certain subtypes such as transsphenoidal variants may be as rare as 1 in 700 000 live births. These rare encephaloceles are classified into five anatomic types: spheno-ethmodial, transsphenoidal, spheno-orbital, transethmoidal, and spheno-maxillary. Here we present an exceedingly rare variant of a non-midline basal encephalocele of the spheno-orbital type, which was treated by resection of the encephalocele, which contained dysplastic central nervous system tissue, on day four post partum. The patient had no neurological deficits and a six year follow-up showed a normal intellect and a good cosmetic result.

Surgery for right-sided colonic diverticulitis: results of a 10-year-observation period.

INTRODUCTION: In contrast to sigmoid diverticular disease, right colonic diverticulitis is a rare disease in Western countries. The clinical presentation is often similar to acute appendicitis. OBJECTIVE: The aim of this study was to analyze surgical challenge in right-sided diverticulitis. MATERIALS AND METHODS: All patients who underwent resection for both right-sided and sigmoid diverticular disease were registered prospectively in a database (observation period, 1996-2005). A retrospective analysis of all patients who underwent resection for right-sided colonic diverticulitis (ileocolic resection, right colectomy) was performed. Special focus was set on incidence, clinical symptoms, indication, procedure, clinical outcome, and histopathologic findings including immunohistochemistry. RESULTS: From a total of 593 patients treated surgically for recurring or acute complicated diverticular disease, the majority (97.8%) suffered from sigmoid diverticulitis (n = 580), whereas 2.2% (n = 16) underwent surgery for right-sided diverticulitis (including three patients with combined sigmoid and cecal diverticulitis). Related to the total number of appendectomies (n = 1167), this represented an incidence of 1.4%. In five of 16 patients, acute appendicitis was presumed preoperatively. Most common diagnostic was ultrasonography. In the group of patients with right-sided diverticulitis, the most common procedure was right hemicolectomy (n = 10), followed by ileocolic resection (n = 3) and combined right colonic resection with sigmoid resection (n = 3). Histopathological investigation confirmed complicated diverticulitis of the cecum with local perforation or abscess in 75% of the patients (12/16). Hypoganglionosis or aganglionosis was diagnosed in seven of the 16 resected specimens. DISCUSSION: As right-sided diverticulitis is a rare colonic disease in Western countries, the differentiation from acute appendicitis may be difficult. In general, there is no difference in the treatment of right-sided diverticulitis compared to left-sided diverticulitis. As most cases will remain clinically unimminent, surgery is only indicated in complicated right-sided cases. Resection of the inflamed colonic segment with primary anastomosis is safe and can be performed laparoscopically. It can only be speculated whether hypoganglionosis or aganglionosis is a causative factor in the etiology of right-sided diverticulitis.

"Occult" mastocytosis with activating c-kit point mutation evolving into systemic mastocytosis associated with plasma cell myeloma and secondary amyloidosis.

A case of a 70-year-old man presenting with exsudative enteropathy due to light-chain-associated amyloidosis is reported. The diagnosis of systemic mastocytosis associated with IgG/lambda plasma cell myeloma and secondary generalised amyloidosis was carried out by morphological evaluation of bone marrow biopsy. The c-kit point mutation D816Y was detected by molecular analysis. Two years before, a cystadenolymphoma of the left parotid gland had been removed. A moderate increase of loosely scattered spindle-shaped mast cells, a subpopulation of them expressing CD25, an antigen that is not expressed by normal or reactive mast cells, was shown by retrospective analysis carried out on an intraparotideal lymph node. The c-kit mutation D816Y was shown by the molecular analysis of the lymph node. In summary, the notion that systemic mastocytosis may very rarely be associated with B cell neoplasms and that neoplastic mast cell infiltrates may be obscured because of only a minimal increase of atypical mast cells, which are outnumbered by other non-neoplastic cells in the same tissue, is supported by this case. This finding was preliminarily termed "occult" mastocytosis.

An unusual case of systemic mastocytosis associated with chronic lymphocytic leukaemia (SM-CLL).

AIMS: Whereas focal accumulations of reactive lymphocytes around mast cell (MC) infiltrates are often seen in indolent systemic mastocytosis (ISM) involving the bone marrow, an association of systemic mastocytosis (SM) with malignant lymphoma/lymphatic leukaemia is very rare. This report contributes to the differential diagnosis of ISM by demonstrating that such lymphocytic aggregates may be neoplastic. METHODS: Biopsy specimens (bone marrow and gastrointestinal mucosa) of a 69 year old woman with mild blood lymphocytosis and a history of urticaria pigmentosa-like skin lesions that had disappeared a few years earlier, were investigated immunohistochemically using antibodies against CD3, CD5, CD20, CD23, CD25, CD34, CD117, chymase, and tryptase. Rearrangements of the IgH and TCRy genes were studied by seminested PCR. Mutation analysis of c-kit was performed by melting point analysis of nested PCR using amplified DNA from pooled microdissected single cells (MC and B cells) of both sites. RESULTS: The histomorphological features of the bone marrow corresponded to that of ISM with multifocal accumulations of MC surrounded by clusters of lymphocytes of mature appearance. However, these lymphocytes revealed an aberrant immunophenotype with coexpression of CD5, CD20, and CD23, thus enabling the final diagnosis of SM with an associated clonal haematological non-MC lineage disease, in particular SM with associated B cell chronic lymphocytic leukaemia (SM-CLL). Monoclonality for both ISM and B-CLL could be confirmed by demonstrating the typical activating c-kit point mutation D816V in bone marrow MC, and a monoclonal IgH rearrangement in bone marrow B cells. CONCLUSIONS: Usually, focal accumulations of lymphocytes around MC infiltrates in the bone marrow of patients with SM are reactive in nature (lymphocytosis). However, a low grade malignant lymphoma should also be included in the differential diagnosis. We describe here the first case, to our knowledge, with synchronous diagnosis of SM and associated B-CLL. This diagnosis could only be established by application of appropriate immunohistochemical and molecular techniques, as the bone marrow histology on first investigation resembled that of typical ISM.

The tryptase positive compact round cell infiltrate of the bone marrow (TROCI-BM): a novel histopathological finding requiring the application of lineage specific markers.

AIMS: Compact tryptase-positive round cell infiltrates of the bone marrow (TROCI-BM) are very rare histopathological findings and may pose challenging problems with regard to the cell type involved (either mast cells or basophilic granulocytes) and the exact diagnosis. METHODS: A selected panel of immunohistochemical markers against mast cell and basophil related antigens, including CD25, CD34, CD117/Kit, and the 2D7 antigen (which is found only in basophilic granulocytes) on a total of 410 routinely processed bone marrow biopsy specimens (including 88 cases of systemic mastocytosis (SM), 20 cases of chronic myeloid leukaemia (CML), 92 cases of myeloid neoplasms other than CML, and 210 controls with normal/reactive bone marrows). RESULTS: In total, 17 cases with TROCI-BM could be identified: 11 SM (including two cases of well-differentiated SM and two mast cell leukaemias; MCL), 2 myelomastocytic leukaemia (MML), 2 CML with excess of basophils (secondary basophilic leukaemia (CMLba)), and 2 tryptase positive acute myeloid leukaemia (AML). Regarding the cell types involved, TROCI-BM cells were found to express CD117/Kit in all cases of SM and MCL. In MML and tryptase postitive AML, TROCI-BM cells were found to coexpress CD34 and Kit. The basophil specific antigen 2D7 was only detected in CD34/Kit negative TROCI-BM cells in two patients with CMLba. The activating point mutation D816V was detected in 8/11 patients with SM but not in any of the other haematological malignancies. CONCLUSIONS: In summary, a total of six rare myeloid neoplasms may present with a novel immunohistochemical phenomenon tentatively termed TROCI-BM.

[Perforated jejunal divertikula - a rare differential diagnosis of acute abdominal pain]. / Das perforierte Jejunaldivertikel - eine seltene Differentialdiagnose des akuten Abdomens.

UNLABELLED: DIAGNOSTIC FINDINGS: We report about a 83 years old female with persisting abdominal pain for 3 days. Abdominal x-ray, as well as abdominal ultrasound examination were unsuccessful. CT scan revealed a 7 cm tumor, suspicious for abscess. OPERATION: Diagnostic laparotomy showed a 6 cm inflammatory tumor with covered perforation of a jejunal diverticula at the 4th intestinal loop distal the ligament of Treitz. We performed a segmental resection. FOLLOW UP: Clinical follow-up was uneventful, the patient was without any symptoms within the first 6 months. Pre- and intraoperative pathology will be explained and discussed referring to the literature.

Sero-genetic studies on the Basters of Rehoboth, South West Africa/Namibia.

The Basters of Rehoboth in South West Africa/Namibia arose by hybridization between Caucasoids and Khoi ('Hottentots') in the northern Cape Province of South Africa during the eighteenth and nineteenth centuries, followed by migration of a single well-defined party to Rehoboth and the consolidation of an ethnocentric nation there. Although there has been some gene flow into the population during the twentieth century, the present sero-genetic study contributes further evidence for the hypothesis of Fisher (1913) that each ancestral strain had furnished an equal contribution to the population.