Aberrant CCND1 copies and cyclin D1 mRNA expression do not result in the production of functional cyclin D1 protein in anaplastic large cell lymphoma.

Scattered reports in the literature have shown that Cyclin D1 mRNA and protein may be expressed in anaplastic large cell lymphoma (ALCL). ALCLs are characterized by the presence of ALK translocations. Aberrant Cyclin D1 expression seems to promote proliferation in other types of lymphoma, while a growth promoting CCND1/TACSD1(TROP2) fusion product has also been described in tumors. Herein, we investigated 44 ALCL cases for chromosome 11 and CCND1 status (by FISH), cyclin D1 mRNA expression (by in situ hybridization and RT-PCR) and Cyclin D1 protein (by immunohistochemistry with two different monoclonal antibodies), as well as for the expression of Trop-2/GA733-1 (by immunohistochemistry). Polysomy of CCND1 (11q13) and chromosome 11 was found in 15/38 evaluated cases (39.5%). This change was specific for CD30+ neoplastic cells, as shown by double fluorescent staining. Neoplastic cells in the majority of ALCL expressed cyclin D1 mRNA (29/41 [70.7%]), in association with the presence of ALK translocations (p=0.024) and systemic, rather than cutaneous disease (p=0.021). Remarkably, however, Cyclin D1 protein was not detected in neoplastic cells (0/44 cases), neither were these found positive for Trop-2. In conclusion, aberrant copies of CCND1 / chromosome 11 may be observed in ALCL, probably as a consequence of the reported ploidy changes in these tumors. ALCL may often express cyclin D1 mRNA, which, however, does not result in the production of functional Cyclin D1 protein or Trop-2, suggesting that these proteins do not play a role in the pathogenesis of ALCL.

Mesectodermal leiomyoma of the ciliary body: report of a case and review of the literature.

Mesectodermal leiomyoma of the ciliary body is a rare benign tumor with double (muscular and neural) differentiation. This neoplasm is considered to originate from the ciliary body smooth muscle, a neural crest derivative. We report a case of mesectodermal leiomyoma of the right eye occurring in a 53-year-old woman, who presented with significant decrease of visual acuity. A malignant melanoma was highly suspected on clinical evaluation, and the globe was enucleated. The tumor measured 1.2cm in greatest dimension, and consisted of spindle and ovoid cells with abundant fibrillary cytoplasmic processes. Immunohistochemical stains revealed positivity for smooth muscle actin, caldesmon, neuron-specific enolase, and CD56 antigen. A review of the 23 cases thus far reported in the literature shows a striking predilection for women, as well as significant difficulties in differentiating this tumor from malignant melanoma on clinical grounds.

In situ detection of hTERT variants in anaplastic large cell lymphoma.

The expression of hTERT and its isoforms is difficult to assess in lymphoma tissues with the commonly used reverse transcription-polymerase chain reaction (RT-PCR) methods, because non-neoplastic lymphocytes expressing hTERT are always present in the lymphomatous infiltrates. The present study aimed to investigate hTERT mRNA variants in anaplastic large cell lymphoma (ALCL) (n = 38) with in situ hybridization (ISH), along with the immunodetection of hTERT protein. Probes for the identification of mRNAs containing (Bplus) and lacking (Bdel) exons 7 and 8 of the hTERT mRNA were used. Normal lymphocyte populations equally expressed both Bplus and Bdel mRNAs. Although all ALCL examined were found positive for hTERT expression with RT-PCR, hTERT mRNAs were identified in 68% of these tumors with ISH, with a higher incidence in the group bearing ALK translocations (10 out of 11; 90.9%) compared to the ALK negative group (17 out of 27; 59.3%) (PPearson's = 0.002). The same results were obtained with immunohistochemistry for hTERT. In approximately 50% of cases, only Bplus positive cells were identified, again with a higher incidence in the ALK positive compared to the ALK negative group (PPearson's = 0.016). In conclusion, ISH for hTERT mRNAs appears to be a valuable tool for the investigation of hTERT expression in lymphomas. Aberrations in hTERT variant profiles and a decline in the expression of the B deleted isoform may be associated with the pathogenesis of ALCL, especially with respect to ALK positive tumors.

hTERT immunopositivity patterns in the normal brain and in astrocytic tumors.

Accumulating data about the impact of hTERT in astrocytic tumor carcinogenesis and recent evidence about its association with disease outcome prompt the evaluation of this molecule with methods applicable in routine pathology practice. In this study, we investigated hTERT protein expression with immunohistochemistry (IHC) and the NCL-hTERT antibody in 49 astrocytic tumors. Results were validated with the assessment of hTERT mRNA (relative quantification, identification of splice variants, in situ hybridization). Specific nuclear hTERT immunostaining patterns (IPs) were characterized as patterns As (single large dot) and Am (multiple dots) without nucleoplasm staining and pattern B (nucleoplasm staining with or without dots), corresponding to low and high relative hTERT expression values (P<0.0001). Low- and high-grade astrocytic tumors were found positive for hTERT in 74 and 85% of cases, respectively. Heterogeneity in the distribution of hTERT-positive cells was observed in all tumors. The prevailing nuclear IPs differed significantly between pilocytic astrocytomas (pattern As) and the rest of histologic types up to glioblastoma (patterns Am and B) (P<0.0001). The described nuclear IPs were also observed in non-neoplastic cells. Positive endothelial cells were found in astrocytic tumors of all grades, even when tumor cells showed no hTERT immunoreactivity. A subset of mature normal neurons was positive for hTERT (pattern As), suggesting a role for this molecule in neuronal maintenance in the adult brain. The nuclear hTERT IPs described here may reflect the functional status of non-neoplastic brain and neoplastic astrocytic cells and support the model of a continuum in the development of glioblastomas from diffuse fibrillary astrocytomas.

Immunohistochemical distinction between merkel cell carcinoma and small cell carcinoma of the lung.

We assessed the usefulness of several immunohistochemical stains in distinguishing these two neoplasms, including cytokeratin 7, cytokeratin 20 (CK20), neuron-specific enolase, chromogranin, synaptophysin, neurofilaments (NF), thyroid-transcription factor-1 (TTF-1), CD56 antigen, S-100 protein, vimentin, c-erbB-2 oncoprotein, and CD117 antigen. All 13 cases of Merkel cell carcinoma evaluated were positive for CK20, and negative for TTF-1. Twelve of 13 Merkel cell carcinoma cases were positive for NF. Eleven of 13 cases of small cell lung carcinoma were positive for TTF-1. All small cell lung carcinoma cases were negative for NF, and all but one were negative for CK20. In terms of the remaining antigens, there were no differences of significance between the two neoplasms. These findings suggest that a set of three immunohistochemical stains, including CK20, NF, and TTF-1, is useful in affording a distinction between Merkel cell carcinoma and small cell lung carcinoma.

Progenitor cell activation in chronic viralhepatitis.

BACKGROUND/AIM: Oval cell proliferation is known to occur in experimental models of hepatic regeneration and carcinogenesis. Recent studies have suggested that activation of progenitor cells, representing the human counterpart of oval cells, may play a role in hepatic diseases. Therefore, we evaluated putative progenitor cells in chronic viral hepatitis. METHODS: Forty-one needle liver biopsy specimens from patients with chronic hepatitis B and 43 specimens from patients with chronic hepatitis C were examined histologically. The grade (histological activity index (HAI)) and stage (degree of fibrosis) were determined on routinely stained sections. The number of progenitor cells was assessed semiquantitatively on cytokeratin 7- (CK 7-) stained sections. RESULTS: In both aetiological categories of chronic viral hepatitis, progenitor cell numbers were found to increase in parallel to the HAI, as well as to the stage of disease. Features suggestive of hepatocytic differentiation of progenitor cells were also noted on immunohistochemical stains for CK 7 and 'hepatocyte-specific' antigen. CONCLUSIONS: In chronic hepatitis B and chronic hepatitis C, progenitor cell activation is correlated with the grade and stage of disease. Proliferating progenitor cells may play a role in hepatic regeneration occurring in this setting.

The canals of hering might represent a target of methotrexate hepatic toxicity.

Methotrexate treatment for psoriasis is known to cause hepatic fibrosis in some patients, which might progress to cirrhosis. The fine, radiating, fibrous septa developing in this setting have a distribution that is reminiscent of the location of the canals of Hering (coH). To assess the possibility of fibrous obliteration of the coH in patients receiving methotrexate, we developed a staining technique by combining an immunohistochemical stain for cytokeratin 7 with a modified Masson trichrome. Sixteen biopsy specimens from 7 patients were evaluated. The biopsies had a variety of histologic changes, including steatosis, anisonucleosis, multinucleation, chronic inflammation, bile duct damage, and ductular reaction. Fibrosis was present in 13 biopsy specimens (81%) and was mild in 7, moderate in 3, and severe in 3 specimens. Compared with normal (control) liver specimens, biopsy specimensfrom patients receiving methotrexate had decreased numbers of coH (1.9 +/- 0.8 vs 5.2 +/- 1.7; P < .025). In specimens with moderate or severe fibrosis, fibrous septa sometimes extended along the coH. These findings suggest that scarring of the coH might be a consequence of the toxic effects of methotrexate.

An extremely rare case of synchronous occurrence in the larynx of intravascular lymphoma and in situ squamous cell carcinoma.

We present the first case of laryngeal intravascular lymphoma coexisting with in situ squamous cell carcinoma. The patient, a 53 years old man, presented with hoarseness starting a year ago and underwent laryngoscopy, which revealed two nodular lesions on his right vocal cord. The histological and immunohistochemical examination of the biopsy specimens established the diagnosis of in situ squamous cell carcinoma coexisting with intravascular lymphoma of T-cell origin. Taking in consideration all the available references, the larynx has not until now been reported as a primary site of involvement of intravascular (angiotropic) lymphomas, nor as a secondary location in the systematic course of this disease. Furthermore no cases have been reported in the literature, concerning the synchronous affection of the larynx by this lymphoma and in situ laryngeal carcinoma, or other type of neoplasm.

Mismatch repair gene expression in malignant lymphoproliferative disorders of B-cell origin.

We investigated mismatch repair (MMR) gene expression in 31 lymphoid tissue specimens and bone marrow aspirates with malignant lymphoproliferative disorders of B-cell origin (25 cases of lymphoma and six cases of plasma cell myeloma). A multiplex RT-PCR assay was employed to assess the relative expression of the hMSH2, hMLH1 and hPMS1 genes, as compared to beta-actin, which was used as an internal control of gene expression. MSH2 was further evaluated at the protein level by immunohistochemistry. The findings were compared to those of a control group of lymphoid tissue specimens without evidence of malignancy (n = 6). Changes in MMR gene expression were observed in 10 out of 31 cases of the study group (32%). All three MMR gene transcripts were low in two out of six plasma cell myelomas, which had extensive bone marrow infiltration by neoplastic cells. The hMSH2 transcript was present in all cases of lymphoma, while the expression of hMLH1 and hPMS1 was significantly low in some large B-cell lymphomas (four and five out of 14 cases, respectively) and in mantle cell lymphomas of the blastoid type (two out of two cases). No MMR gene aberrations were found in seven cases of B-cell lymphocytic leukemia and two cases of mantle cell lymphoma of centrocyte-like type. These findings demonstrate that the expression rates of the hMSH2, hMLH1 and hPMS1 genes differ among various types of B-cell lymphoproliferative disorders, and suggest that MMR gene expression may be related to the natural history of these neoplasms. This study identified a higher incidence of MMR gene aberrations in lymphoma types characterized by aggressive biologic behavior, as compared to neoplasms with a more indolent course.

A 25-year-old man with a large hepatic tumor and multiple nodular lesions.

A 25-year-old man without a prior history of liver disease presented with an 18-cm tumor of the right hepatic lobe, which was associated with multiple nodular lesions in the remaining parenchyma. The histologic and immunohistochemical features of the neoplasm were those of a poorly differentiated leiomyosarcoma with epithelioid features. The nodular lesions measured up to 4 cm in greatest dimension and had gross and microscopic features of focal nodular hyperplasia. This case suggests that multiple focal nodular hyperplasia may occasionally represent a parenchymal reaction to abnormal blood supply developing within the liver as a consequence of an enlarging malignant tumor.

Expression of human telomerase reverse transcriptase in regenerative and precancerous lesions of cirrhotic livers.

BACKGROUND/AIMS: The catalytic subunit of human telomerase (hTERT) is known to be expressed in a variety of malignant tumours, including hepatocellular carcinoma (HCC). We studied hTERT expression in regenerative and precancerous lesions arising in cirrhosis. METHODS/RESULTS: As shown by in situ hybridisation, hTERT mRNA was absent in normal liver, but present in varying numbers of hepatocytes and HCC cells of diseased livers, as well as in biliary epithelial cells, lymphocytes, sinusoidal-lining cells and tumour endothelial cells. RT-PCR for two hTERT transcript regions demonstrated hTERT expression in 11 out of 15 cirrhotic liver samples, in 20 out of 21 large regenerative nodules/low-grade dysplastic nodules, in 5 out of 5 high-grade dysplastic nodules, and in 4 out of 4 HCCs. The beta-splice variant was identified in all hTERT-positive cases, while the corresponding full-length transcript was found only in 13 out of 29 positive large nodular lesions and in 4 out of 11 positive cirrhotic samples. The full-length transcript was always found in the presence of the beta-splice variant, usually in low relative levels, and tended to correlate with telomerase activity in the samples, while the beta-splice variant did not. CONCLUSIONS: This study shows that hTERT re-expression takes place both in hepatic regeneration occurring in cirrhosis and in the early steps of hepatocarcinogenesis, and involves mainly the beta-splice variant of this molecule. Additional regulatory mechanisms may be required for the expression of the full-length hTERT transcript.