Molecular Diagnosis of Cutaneous T-Cell Lymphoma: Polymerase Chain Reaction Amplification of T-Cell Antigen Receptor β-Chain Gene Rearrangements

The goal of our study was to molecularly diagnose CTCL, by cloning the T-cell antigen receptor beta chain (TCR-β) gene rearrangement from the malignant T cells of a patient with Sézary syndrome, in order to generate a specific oligonucleotide probe capable of detecting CTCL cells through polymerase chain reaction (PCR) amplification. Total RNA isolated from peripheral blood lymphocytes was reverse transcribed and resultant first strand cDNA was PCR amplified utilizing a concensus primer to the TCR-β variable region (Vβ) and a 3' primer to the TCR-β constant region (Cβ). PCR reaction products were subcloned into a plasmid vector and sequenced. Sequence analysis revealed that the patient's in-frame TCR-β gene rearrangement utilized Vβ6.4, Dβ1.1, Jβ2.2, and Cβ2.1 gene segments. Oligo-primers to Vβ6.4 and Jβ2.2 were utilized to PCR amplify genomic DNA taken from the patient's blood and involved skin. Screening the amplified DNA with an oligoprobe specific for the patient's V-D-J junctional sequences resulted in the detection of the patient- specific sequences. No sequences were detected from DNA from other malignant or benign infiltrates. Thus, we have defined a “molecular fingerprint” specific for a patient's malignant T-cells and can molecularly diagnose CTCL through PCR amplification

DNA-Cytophotometry of Lymph Node Touch Imprints in Cutaneous T-Cell Lymphoma

Scanning DNA-cytophotometry was performed on touch imprints of 26 lymph nodes (LN) obtained from 25 patients with cutaneous T-cell lymphoma (CTCL), stained by the Feulgen technique, and interpreted without knowledge of histopathologic diagnosis. Four patterns of DNA distribution were identified, but only histograms that demonstrated cells containing nuclei with more than 4C DNA content (hypertetraploidy) reliably distinguished LN involved with CTCL from LN with reactive changes; for example, dermatopathic lymphadenitis. An abnormal DNA histogram with evidence of hypertetraploidy was demonstrated in 9 of 12 LN showing histopathologic evidence of involvement compared with no abnormal histograms in 14 LN without histopathologic involvement. One LN that was diffusely involved with CTCL had a DNA distribution characteristic of a relatively high level of cell proliferation, but without definite hypertetraploidy. Cytogenetic studies on the blood of this patient, who had Sézary syndrome, demonstrated a clone of lymphocytes with a pseudodiploid karyotype without a related polyploid subline. The remaining two histopathologically involved LN had normal DNA histograms; these LN were only focally involved with CTCL. These observations indicate that DNA-cytophotometry correlates well with the histopathologic findings in LN diffusely involved with CTCL, but may be normal in LN with focal involvement or in those that contain cytogenetically abnormal cells with a near-dip- kid DNA content

Clinicopathologic correlation of cutaneous metastases: experience from a cancer center.

OBJECTIVE: To analyze the clinical, histopathologic, and immunohistochemical characteristics of skin metastases. DESIGN: Retrospective analysis (January 1, 1990, to December 31, 2005). SETTING: Comprehensive cancer center. PATIENTS: Fifty-one patients (21 men and 30 women) with biopsy-proven skin metastases and correlative clinical data. INTERVENTIONS: Four dermatopathologists reviewed a random mixture of metastases and primary skin tumors. Immunohistochemical studies for 12 markers were performed on the metastases, with skin adnexal tumors as controls. MAIN OUTCOME MEASURES: Clinical characteristics of cutaneous lesions, clinical outcomes, histologic features, and immunohistochemical markers. RESULTS: Eighty-six percent (43 of 50) of the patients had known stage IV cancer, and skin metastasis was the presenting sign in 12% (6 of 50). In 45% (21 of 47) of the biopsies, the lesions were not suspected of being metastases owing to unusual clinical presentations. Seventy-six percent of the patients died of disease (median survival, 5 months). On pathologic review, many metastases from adenocarcinomas were either recognized or suspected, but the primary site was not easily identified based on histologic findings alone. Metastases from small cell carcinomas and sarcomas were histologically misinterpreted as primary skin tumors. Immunohistochemical analysis using a panel including p63, B72.3, calretinin, and CK5/6 differentiated metastatic carcinoma from primary skin adnexal tumors. CONCLUSIONS: Cutaneous metastases can have variable clinical appearances and can mimic benign skin lesions. They are usually seen in patients with advanced disease, but they can be the presenting lesion. Although many metastatic adenocarcinomas can be recognized based on histologic findings alone, immunohistochemical analysis is an important diagnostic adjunct in some cases