Potential molecular mechanism in self-renewal is associated with miRNA dysregulation in sacral chordoma - A next-generation RNA sequencing study

Background

Chordoma, the most frequent malignant primary spinal neoplasm, characterized by a high rate of recurrence, is an orphan disease where the clarification of the molecular oncogenesis would be crucial to developing new, effective therapies. Dysregulated expression of non-coding RNAs, especially microRNAs (miRNA) has a significant role in cancer development.

Methods

Next-generation RNA sequencing (NGS) was used for the combinatorial analysis of mRNA-miRNA gene expression profiles in sacral chordoma and nucleus pulposus samples. Advanced bioinformatics workflow was applied to the data to predict miRNA-mRNA regulatory networks with altered activity in chordoma.

Results

A large set of significantly dysregulated miRNAs in chordoma and their differentially expressed target genes have been identified. Several molecular pathways related to tumorigenesis and the modulation of the immune system are predicted to be dysregulated due to aberrant miRNA expression in chordoma. We identified a gene set including key regulators of the Hippo pathway, which is targeted by differently expressed miRNAs, and validated their altered expression by RT-qPCR. These newly identified miRNA/RNA interactions are predicted to have a role in the self-renewal process of chordoma stem cells, which might sustain the high rate of recurrence for this tumor.

Conclusions

Our results can significantly contribute to the designation of possible targets for the development of anti-chordoma therapies.

Cell Cycle Regulatory Protein Expression in Multinucleated Giant Cells of Giant Cell Tumor of Bone: do They Proliferate?

Cells of the monocyte macrophage lineage form multinucleated giant cells (GCs) by fusion, which may express some cell cycle markers. By using a comprehensive marker set, here we looked for potential replication activities in GCs, and investigated whether these have diagnostic or clinical relevance in giant cell tumor of bone (GCTB). GC rich regions of 10 primary and 10 first recurrence GCTB cases were tested using immunohistochemistry in tissue microarrays. The nuclear positivity rate of the general proliferation marker, replication licensing, G1/S-phase, S/G2/M-phase, mitosis promoter, and cyclin dependent kinase (CDK) inhibitor reactions was analyzed in GCs. Concerning Ki67, moderate SP6 reaction was seen in many GC nuclei, while B56 and Mib1 positivity was rare, but the latter could be linked to more aggressive (p = 0.012) phenotype. Regular MCM6 reaction, as opposed to uncommon MCM2, suggested an initial DNA unwinding. Early replication course in GCs was also supported by widely detecting CDK4 and cyclin E, for the first time, and confirming cyclin D1 upregulation. However, post-G1-phase markers CDK2, cyclin A, geminin, topoisomerase-2a, aurora kinase A, and phospho-histone H3 were rare or missing. These were likely silenced by upregulated CDK inhibitors p15^INK4b, p16^INK4a, p27^KIP1, p53 through its effector p21^WAF1 and possibly cyclin G1, consistent with the prevention of DNA replication. In conclusion, the upregulation of known and several novel cell cycle progression markers detected here clearly verify early replication activities in GCs, which are controlled by cell cycle arresting CDK inhibitors at G1 phase, and support the functional maturation of GCs in GCTB.

Papillary Endothelial Hyperplasia (Masson Tumor) of the Hand. Surgical and Pathological Consideration from Seven Cases Using New Vascular Markers

Although papillary endothelial hyperplasia may occur at almost any site, one of the most common sites is the hand. It is generally regarded as a reactive vascular proliferation i.e. exuberant form of organizing thrombus. Diagnosis of Masson tumor can be challenging due to its close clinical, radiological and even histopathological resemblance to angiosarcoma. We present seven cases of Masson tumor of the hand; wanting to reveal its nature using new vascular markers and discuss the treatment options and expected outcomes, present clinical and radiological features that may aid diagnosis and also offer treatment plans. A multicenter retrospective study was performed between January 2014 and November 2019. Immunohistochemical stains of Glut1, WT1, ERG, CD31 and alpha smooth muscle actin (ASMA) were performed on each cases. We found seven cases during the examined period. 4 out of 7 cases were women. All lesions occurred in the hands. 3 out of 7 cases appeared in a previously present vascular malformation. All cases were treated with surgical excision and the diagnosis of papillary endothelial hyperplasia was made by histology. Pre-operative testing (radiograph/MRI/US/fine needle aspiration biopsy) did not suggest the diagnosis of Masson tumor; however, aspiration cytology could rule out malignancy. The proliferative endothelial cells proved to be Glut1 negative and WT1 positive and the accompanying pericytic cells were ASMA positive in all cases. Though Masson tumor is a rare vascular lesion in the hand among other vascular tumors, it should be considered in the differential diagnostics even in the case of previously existing vascular malformation. WT1 positivity of the endothelial cells and the accompanying pericytic cells raises the question whether the initially reactive endothelial proliferation may transform into a true benign vascular tumor.

In situ cell cycle analysis in giant cell tumor of bone reveals patients with elevated risk of reduced progression-free survival

OBJECTIVE

Giant cell tumor of bone (GCTB) is a frequently recurring locally aggressive osteolytic lesion, where pathological osteoclastogenesis and bone destruction are driven by neoplastic stromal cells. Here, we studied if cell cycle fractions within the mononuclear cell compartment of GCTB can predict its progression-free survival (PFS).

METHODS

154 cases (100 primaries and 54 recurrent) from 139 patients of 40 progression events, was studied using tissue microarrays. Ploidy and in situ cell cycle progression related proteins including Ki67 and those linked with replication licensing (mcm2), G1-phase (cyclin D1, Cdk4), and S-G2-M-phase (cyclin A; Cdk2) fractions; cell cycle control (p21^waf1) and repression (geminin), were tested. The Prentice-Williams-Peterson (PWP) gap-time models with the Akaike information criterion (AIC) were used for PFS analysis.

RESULTS

Cluster analysis showed good correlation between functionally related marker positive cell fractions indicating no major cell cycle arrested cell populations in GCTB. Increasing hazard of progression was statistically associated with the elevated post-G1/S-phase cell fractions. Univariate analysis revealed significant negative association of poly-/aneuploidy (p < 0.0001), and elevated cyclin A (p < 0.001), geminin (p = 0.015), mcm2 (p = 0.016), cyclin D1 (p = 0.022) and Ki67 (B56: p = 0.0543; and Mib1: p = 0.0564 -strong trend) positive cell fractions with PFS. The highest-ranked multivariate interaction model (AIC = 269.5) also included ploidy (HR 5.68, 95%CI: 2.62-12.31, p < 0.0001), mcm2 (p = 0.609), cyclin D1 (HR 1.89, 95%CI: 0.88-4.09, p = 0.105) and cyclin A (p < 0.0001). The first and second best prognostic models without interaction (AIC = 271.6) and the sensitivity analysis (AIC = 265.7) further confirmed the prognostic relevance of combining these markers.

CONCLUSION

Ploidy and elevated replication licensing (mcm2), G1-phase (cyclin D1) and post-G1 phase (cyclin A) marker positive cell fractions, indicating enhanced cell cycle progression, can assist in identifying GCTB patients with increased risk for a reduced PFS.

Antitumor immune response induced by NBTXR3 activated by radiotherapy

e14609

Background: Radiotherapy (RT) can prime an anti-tumor immune response. Unfortunately, this response rarely generates total tumor destruction and abscopal effect. When activated by RT, intratumorally (IT) administered hafnium oxide nanoparticles (NBTXR3) locally increase radiation dose deposit and tumor cell death compared to RT alone. We hypothesized that NBTXR3 + RT could enhance the anti-tumor immune response, both in mice and humans. Methods: Murine CT26 cells were injected in both flanks of immunocompetent mice. When tumor volume reached 50-120mm3, NBTXR3 (or vehicle) was injected IT in right flank tumors only, then irradiated (3x4Gy). Mice were sacrificed when tumors reached 800mm3. Alternatively, tumors were collected 3 days after last RT fraction and immune cell infiltrates analyzed by immunohistochemistry (IHC). Patients (pts) with locally advanced Soft Tissue Sarcoma (STS) (NCT02379845) received NBTXR3 + RT or RT alone. Pre- and post-treatment (biopsy and resection, respectively) tumor tissues from pts were analyzed by IHC and Digital Pathology for immune biomarkers ( > 16 pts per arm). Results: In mice, IHC analyses showed an increase of CD8+ T cells infiltrates in both flanks of mice treated with NBTXR3+RT, while this was not observed in animals treated with RT alone. Furthermore, ICH analysis of post- vs pre-treatment samples from STS pts showed a marked increase of CD8+ and PD1 biomarkers for pts treated with NBTXR3 + RT, while no differences were seen for pts treated with RT alone. Conclusions: NBTXR3 + RT markedly changes the tumor immune profile in a similar manner in mice and pts with STS. We hypothesize that this adaptive immune response could help convert a local tumor microenvironment to a “hot” phenotype and thus improve the efficacy of immune checkpoint inhibitors. These results led us to investigate the safety and systemic effect of NBTXR3 activated by stereotactic ablative RT (SABR) in combination with anti-PD-1 antibody in pts with locoregionally recurrent or metastatic (to lung or liver) Head and Neck squamous cell carcinoma HNSCC, as well as in metastatic non-small cell lung cancer (NSCLC) and liver metastasis patients [NCT03589339].

Sirolimus therapy in the treatment of pseudomyogenic hemangioendothelioma

Pseudomyogenic hemangioendothelioma (PMH) is a rare, mostly indolent vascular tumor. Extensive cases are treated with amputation as chemotherapy seems to be ineffective. Recently, promising results were published using mammalian target of rapamycin (mTOR) inhibitors in tumors of vascular origin. Here, we present a case of a child with advanced PMH relapsing after surgery and chemotherapy. Sirolimus achieved significant clinical improvement and stabilization of the lesions without any remarkable toxicity. This case contributes to the growing evidence regarding the efficacy of mTOR inhibitors, such as sirolimus, in multifocal PMH.

Uncommon presentation of a rare tumour - incidental finding in an asymptomatic patient: case report and comprehensive review of the literature on intrapericardial solitary fibrous tumours

Background

A solitary fibrous tumour is a rare, mainly benign spindle cell mesenchymal tumour most commonly originating from the pleura. An intrapericardial location of a solitary fibrous tumour is extremely unusual. We present a case of an asymptomatic patient with a slow-growing massive benign cardiac solitary fibrous tumour.

Case presentation

A 37-year-old asymptomatic female patient was referred to our hospital with an enlarged cardiac silhouette found on her screening chest X-ray. The echocardiographic examination revealed pericardial effusion and an inhomogeneous mobile mass located in the pericardial sac around the left ventricle. Cardiac magnetic resonance (MRI) examination showed an intrapericardial, semilunar-shaped mass attached to the pulmonary trunk with an intermediate signal intensity on proton density-weighted images and high signal intensity on T2-weighted spectral fat saturation inversion recovery images. First-pass perfusion and early and late gadolinium-enhanced images showed a vascularized mass with septated, patchy, inhomogeneous late enhancement. Coronary computed tomography angiography revealed no invasion of the coronaries. Based on the retrospectively analysed screening chest X-rays, the mass had started to form at least 7 years earlier. Complete resection of the tumour with partial resection of the pulmonary trunk was performed. Histological evaluation of the septated, cystic mass revealed tumour cells forming an irregular patternless pattern; immunohistochemically, the cells tested positive for vimentin, CD34, CD99 and STAT6 but negative for keratin (AE1-AE3), CD31 and S100. Thus, the diagnosis of an intrapericardial solitary fibrous tumour was established. There has been no recurrence for 3 years based on the regular MRI follow-up.

Conclusion

Intrapericardial SFTs, showing slow growth dynamics, can present with massive extent even in completely asymptomatic patients. MRI is exceedingly useful for characterizing intrapericardial masses, allowing precise surgical planning, and is reliable for long-term follow up.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3574-0) contains supplementary material, which is available to authorized users.

Specific adaptive immune pattern induced by NBTXR3 exposed to radiation therapy in soft tissue sarcoma (STS) patients

e14615

Background: NBTXR3 are functionalized hafnium oxide nanoparticles, undergoing seven clinical trials for enhancing radiation therapy (RT). The high electron density of the nanoparticles, when exposed to radiotherapy (NBTXR3 + RT), allow absorption/deposition of a high radiation dose within the cancer cells to physically kill the cells, and possibly improve outcome. Besides, NBTXR3 + RT has shown subsequent ability to enhance immunogenic cell death and immune response in preclinics. We hypothesized that NBTXR3 + RT could trigger an enhanced immune response when compared to RT in patients with STS. Methods: Tumor tissues pre- (biopsy) and/or post-treatment (resection) were collected from patients (pts) with locally advanced STS, who received either NBTXR3 as intratumor injection and RT (14 pts) or RT (12 pts), as preoperative treatment (NCT02379845). Immunohistochemistry and Digital Pathology for immune biomarkers and for Immunoscore (CD3/CD8) were analyzed. Gene expression profiling and pre-optimized immune-gene signatures called Immunosign were also used. Results: A significant increase of T cells (CD3+, CD8+) and a marked increase of CD103+ immune cell infiltration post- vs pre-treatment were observed for NBTXR3 + RT ( P< 0.01), while no differences were seen for RT. Post-treatment, an increased Immunoscore (CD3 + CD8 cell densities) was observed for NBTXR3 + RT compared to RT (P < 0.07). Consistently, the up-regulation of pan immune genes expression and specifically expression of adaptive immunity genes between pre- and post-treatment, was pronounced for NBTXR3 + RT when compared to RT. Functional analysis of genes up-regulated in NBTXR3 + RT showed an enrichment of cytokine activity (IL7, IFNA, IL16, IL11, IFNG), adaptive immunity (RAG1, GZMA, TAP1, TAP2, TBX21, STAT4, IFNG, LCK, LTK, CD37, CD22) and T cell receptor signaling pathway (CD28, CTLA4, CD274, BTLA, TIGIT, CD40LG, CD5, CD3E, ZAP70). Conclusions: NBTXR3 + RT induces a specific adaptive immune pattern. As such, it may contribute to convert “cold” tumor into “hot” tumor and be effectively combined with immunotherapeutic agents across oncology. These data warrant more tissue samples evaluation to reinforce these findings.

Prognostic impact of reduced connexin43 expression and gap junction coupling of neoplastic stromal cells in giant cell tumor of bone

Missense mutations of the GJA1 gene encoding the gap junction channel protein connexin43 (Cx43) cause bone malformations resulting in oculodentodigital dysplasia (ODDD), while GJA1 null and ODDD mutant mice develop osteopenia. In this study we investigated Cx43 expression and channel functions in giant cell tumor of bone (GCTB), a locally aggressive osteolytic lesion with uncertain progression. Cx43 protein levels assessed by immunohistochemistry were correlated with GCTB cell types, clinico-radiological stages and progression free survival in tissue microarrays of 89 primary and 34 recurrent GCTB cases. Cx43 expression, phosphorylation, subcellular distribution and gap junction coupling was also investigated and compared between cultured neoplastic GCTB stromal cells and bone marow stromal cells or HDFa fibroblasts as a control. In GCTB tissues, most Cx43 was produced by CD163 negative neoplastic stromal cells and less by CD163 positive reactive monocytes/macrophages or by giant cells. Significantly less Cx43 was detected in α-smooth muscle actin positive than α-smooth muscle actin negative stromal cells and in osteoclast-rich tumor nests than in the adjacent reactive stroma. Progressively reduced Cx43 production in GCTB was significantly linked to advanced clinico-radiological stages and worse progression free survival. In neoplastic GCTB stromal cell cultures most Cx43 protein was localized in the paranuclear-Golgi region, while it was concentrated in the cell membranes both in bone marrow stromal cells and HDFa fibroblasts. In Western blots, alkaline phosphatase sensitive bands, linked to serine residues (Ser369, Ser372 or Ser373) detected in control cells, were missing in GCTB stromal cells. Defective cell membrane localization of Cx43 channels was in line with the significantly reduced transfer of the 622 Da fluorescing calcein dye between GCTB stromal cells. Our results show that significant downregulation of Cx43 expression and gap junction coupling in neoplastic stromal cells are associated with the clinical progression and worse prognosis in GCTB.

Malignant fibrous histiocytoma/undifferentiated high-grade pleomorphic sarcoma of the maxillary sinus: report of a case and review of the literature

Malignant fibrous histiocytoma (MFH) also known as undifferentiated high-grade pleomorphic sarcoma (UHPS) is a soft tissue sarcoma, composed of undifferentiated mesenchymal tumors possessed fibrohistiocytic morphology without definite true histiocytic differentiation. Head and neck localization is very rare, showing an incidence ranging from 4 % to 10 % in different series of investigations. The most frequent involved sites in UHPS are the neck and parotid, followed by the scalp, face, anterior skull base and orbit. Upper aerodigestive tract, lateral skull base and ear are rare locations. The incidence of the lymphatic metastases is also rare. The aim of this article is to report a case of UHPS in the maxillary sinus with palatal, orbital and ethmoidal involvement, with lymphatic metastasis and its surgical treatment. In addition, we review the literature of similar cases of the past 12 years.

Epidermal growth factor receptor signalling contributes to osteoblastic stromal cell proliferation, osteoclastogenesis and disease progression in giant cell tumour of bone

AIMS

Epidermal growth factor receptor (EGFR) is implicated in bone remodelling. The aim was to determine whether EGFR protein expression contributes to the aggressiveness and recurrence potential of giant cell tumour of bone (GCTB), an osteolytic primary bone tumour that can exhibit markedly variable clinical behaviour.

METHODS AND RESULTS

Immunohistochemical analysis on tissue microarrays (TMA) of 231 primary, 97 recurrent, 17 metastatic and 26 malignant GCTBs was performed using TMA analysis software and whole digital slides allowing validated scoring. EGFR expression was restricted to neoplastic stromal cells and was significantly more frequent in recurrent (71 of 92; 77%) than in non-recurrent GCTBs (86 of 162; 53%) (P = 0.002); and in clinicoradiologically aggressive (31 of 43; 72%) than latent (27 of 54; 50%) cases (P = 0.034). Detecting phosphotyrosine epitopes pY1068 and -pY1173 indicated active EGFR signalling, and finding EGFR ligands EGF and transforming growth factor-α restricted to cells of the monocytic lineage suggested paracrine EGFR activation in stromal cells. In functional studies EGF supported proliferation of GCTB stromal cells, and the addition of EGF and macrophage-colony stimulating factor promoted osteoclastogenesis.

CONCLUSION

In GCTB, EGFR signalling in neoplastic stromal cells may contribute to disease progression through promoting stromal cell proliferation and osteoclastogenesis.

Epidermal growth factor receptor (EGFR) high gene copy number and activating mutations in lung adenocarcinomas are not consistently accompanied by positivity for EGFR protein by standard immunohistochemistry

The purpose of this study was to investigate whether detectable protein biomarker overexpression is a prerequisite for the presence of increased gene copy number or activating mutations and responsiveness to the epidermal growth factor receptor (EGFR) inhibitors gefitinib and erlotinib in patients with lung adenocarcinomas. EGFR status was prospectively analyzed in tumor biopsy samples by three methods: protein expression (n = 117) by standardized immunohistochemistry (IHC), gene copy number (n = 97) by fluorescent in situ hybridization (FISH), and mutation analysis by sequencing (n = 126). Fifty-nine percent of the samples were positive by IHC, 40% were positive by FISH, and 13.5% contained activating kinase domain mutations. Thirty-four percent of the FISH-positive and 27% of the mutant samples were also IHC-negative. All EGFR mutant patients had major clinical responses (five complete response and five partial response) to gefitinib or erlotinib treatment, although three of these tumors were IHC-negative and four were FISH-negative. In a retrospective analysis of samples from nine patients with excellent therapeutic responses (three complete response, five partial response, one stable disease) to erlotinib or gefitinib, mutations were identified in eight cases, but IHC was negative in four of these tumors. These results indicate that molecular diagnostic methods appear to be most important for the identification of lung adenocarcinoma patients who may benefit from EGFR inhibitor treatments.

Myopericytoma of skin and soft tissues: clinicopathologic and immunohistochemical study of 54 cases

Perivascular neoplasms comprise traditionally glomus tumor and hemangiopericytoma (HPC). Whereas glomus tumor represents a well-defined entity, the existence of HPC as a separate entity has been questioned because a number of neoplasms of different lines of differentiation are characterized by a HPC-like vascular growth pattern. Myopericytoma represents a recently delineated entity showing a HPC-like vascular pattern. A large series of myopericytoma of skin and soft tissues has been analyzed to further characterize the clinicopathologic spectrum of this entity. Fifty-four cases of myopericytoma of skin and soft tissues were retrieved and the histology reviewed. Immunohistochemical stainings using alpha-smooth muscle actin (ASMA), desmin, and h-caldesmon antibodies were performed, and clinical data and follow-up information were obtained from referring pathologists. Thirty-four patients were male and 18 were female (gender was unknown in 2 cases). Patient age ranged from 13 to 87 years (median, 52 years). The lower extremities were most commonly affected (26 cases) followed by the upper extremities (16 cases), the head and neck region (4 cases), and the trunk (2 cases); exact location was unknown in 5 cases. In 20 cases, the neoplasms were confined to the dermis, in 6 cases an extension into the subcutis was seen, and 24 as well as 4 cases arose in subcutaneous and deep soft tissue, respectively. Two cases were multicentric; and in 1 of these patients, multiple anatomic regions were involved. Histologically, in all cases, numerous thin-walled vessels and a concentric, perivascular arrangement of ovoid, plump spindled to round myoid tumor cells was seen. However, a broad morphologic spectrum ranging from hypocellular, fibroma-like (3 cases), myofibroma-like (2 cases), angioleiomyoma-like (12 cases), and HPC-like neoplasms (13 cases) to classic myopericytomas (14 cases) and immature, cellular lesions (2 cases) was noted. In addition, 2 neoplasms with focal glomoid features, 5 intravascular, and 1 malignant myopericytomas were found. Prominent cytologic atypia and increased proliferative activity (>3 mitoses/10 high power fields) was seen in 4 and 2 cases, respectively. Immunohistochemically, all cases tested stained positively for ASMA. In addition, 29 of 32 cases tested stained positively for h-caldesmon, whereas desmin was only focally positive in 3 of 33 cases. Follow-up information was available in 46 cases (range, 7-168 months; median, 48 months). Despite marginal or incomplete excision in 23 of 46 cases, only 2 neoplasms (1 malignant and 1 intravascular myopericytoma) recurred locally (within 1 and 4 years, respectively). Despite overlapping morphologic features to angioleiomyoma and myofibroma, myopericytoma represents a distinct perivascular, myoid neoplasm of skin and soft tissues, characterized by a broad morphologic spectrum of concentrically, perivascularly growing myoid tumor cells that stain positively for ASMA and often for h-caldesmon, whereas desmin is usually negative. Most cases of myopericytoma behave in a benign fashion, but local recurrences and rarely metastases may occur in atypical and malignant neoplasms.

Identification of the LAMB3 hotspot mutation R635X in a Hungarian case of Herlitz junctional epidermolysis bullosa

The Herlitz type of junctional epidermolysis bullosa (H-JEB) is a severe blistering disease affecting the skin and mucous membranes, which is usually lethal within the first year of life. The laminin 5 genes have been implicated as candidate genes for most patients with H-JEB. Recently, two hotspot mutations were delineated in the LAMB3 gene, known as R42X and R635X, and have been noted in over 50% of mutant LAMB3 alleles. Here, we present a case of H-JEB of Hungarian origin with a neonatal lethal outcome. Monoclonal antibody staining showed a lack of expression of the laminin 5 beta 3 chain, as a possible result of a mutation in one of the laminin 5 genes. Screening of the family identified the previously described mutation R635X in exon 14 of LAMB3 in each of the parents and one healthy sibling in the heterozygous form, while proband was homozygous for R635X, and the other sibling proved to be genotypically normal. These results underscore the widespread prevalence of R635X in H-JEB cases from around the world.

The increasing incidence of prostate cancer in Hungary

Prostate cancer is becoming an increasing health concern world wide, and its significance is also increasing in Hungary, where mortality rates are very similar to those in the United States of America. Mortality from prostate cancer is increasing disproportionately to the aging of Hungarian men or overall population growth, and the explanation for this alarming trend is as yet unexplained. Nevertheless, the data suggest that prostate cancer will continue to assume increasing importance as a medical problem and the need for fundamental epidemiologic investigations is clear.

Ploidy results in prostatic carcinoma vary with sampling method and with cytometric technique

To evaluate the effect of sampling method and cytometric method on DNA ploidy results, a comparison study was performed on 20 whole prostate glands removed at prostatectomy. Fresh sampling was by sampling fine-needle aspiration (FNA). Paraffin sampling was by microdissection and re-embedding of 3 to 13 (average 6) 5-mm foci of microscopically proven tumor. Analysis was by flow cytometry and by image cytometry (microscopically guided). In tumor negative cases, flow and image cytometry of the FNA was diploid in each case, and flow cytometry of paraffin-embedded tissue was diploid in 5/6 cases. In tumor positive cases, non-diploid tumor was detected by image cytometry of the FNA in 70%, by flow cytometry of the FNA in 29%, and by flow cytometry of paraffin-extracted nuclei in 21%. The most effective combination was sampling fine-needle aspiration and image analysis.

Quantitative morphologic assessment of nuclei extracted from paraffin for DNA flow cytometry

We present a method for quality control of flow cytometric DNA content studies using nuclei extracted from paraffin-embedded tissue. This method is based on a quantitative morphologic assessment of extracted nuclei. Cell nuclei prepared from 22 paraffin-embedded tumors known to contain discrete diploid and aneuploid stemlines were deposited onto poly-L-lysine-coated glass slides. Nuclei were stained with Diff-quic and examined by light microscopy. Two hundred nuclei were counted and classified based on morphologic appearance into tumor and nontumor groups. Classification criteria included differences in nuclear size, nuclear chromatin structure, the degree of nuclear chromatin condensation, and the presence of nucleoli. Excellent agreement was found between two independent observers (R = 0.989) on the classification of nuclei. The relative number of tumor nuclei on the morphologic preparation was compared with the relative number of aneuploid cells in the DNA histogram. Good agreement was observed (R = 0.975) in all but three cases in which the relative number of tumor nuclei was underrepresented by the percentage of aneuploid nuclei in the DNA histogram. In each case, further analysis by image cytometry demonstrated a diploid and aneuploid component of the tumor cell population. This quantitative method of morphologic examination of the preparation ultimately analyzed by flow cytometry offers several distinct advantages, including: (a) identification of peaks in the DNA histogram, (b) assessment for selective loss of cell nuclei in the extraction process, and (c) identification of biologic heterogeneity in tumor populations.

Tissue section image analysis of breast neoplasms. Evidence of false aneuploidy

Two methods have emerged for measuring the DNA content of paraffin-embedded tissue using image cytometry: (1) analysis of thin sections, and (2) analysis of nuclei extracted from thick sections. These methods were evaluated using 31 breast tumors for which paraffin-embedded material was available. Cases selected represented 11 diploid, 11 tetraploid, and 9 aneuploid tumors. Results generated using image cytometry methods were compared with those obtained using flow cytometry. For thin sections, the tissue correction feature of the CAS 200 Image Cytometer was used to estimate the DNA content of whole nuclei from measurements made on sectioned nuclei. DNA histograms were generated from tissue sections cut at the same microtome setting (5 microns) before and after software corrections of 4.5 microns, 5.0 microns, 5.5 microns, 6.0 microns. 6.5 microns, 7.0 microns, and 7.5 microns. A comparison of flow cytometry and thin-section image analysis in the absence of tissue correction showed 90% concordance for diploid, 27% concordance for tetraploid, and 77% concordance for aneuploid tumors. The ploidy estimated on thin sections by at least one of the correction values was discordant in 72% of diploid, 91% of tetraploid, and 78% of aneuploid tumors. For cell nuclei extracted from paraffin, excellent agreement was found between flow and image cytometry (r = 0.933). It was concluded that in most cases, cell nuclei extracted from paraffin are preferable to tissue sections for ploidy analysis of breast tumors using image cytometry.