Melanoma in children and adolescents: analysis of susceptibility genes in 123 Italian patients.

BACKGROUND: A polygenic inheritance involving high, medium and low penetrance genes has been suggested for melanoma susceptibility in adults, but genetic information is scarce for paediatric patients. OBJECTIVE: We aim to analyse the major high and intermediate melanoma risk genes, CDKN2A, CDK4, POT1, MITF and MC1R, in a large multicentre cohort of Italian children and adolescents in order to explore the genetic context of paediatric melanoma and to reveal potential differences in heritability between children and adolescents. METHODS: One-hundred-twenty-three patients (<21 years) from nine Italian centres were analysed for the CDKN2A, CDK4, POT1, MITF, and MC1R melanoma predisposing genes. The rate of gene variants was compared between sporadic, familial and multiple melanoma patients and between children and adolescents, and their association with clinico-pathological characteristics was evaluated. RESULTS: Most patients carried MC1R variants (67%), while CDKN2A pathogenic variants were found in 9% of the cases, the MITF E318K in 2% of patients and none carried CDK4 or the POT1 S270N pathogenic variant. Sporadic melanoma patients significantly differed from familial and multiple cases for the young age at diagnosis, infrequent red hair colour, low number of nevi, low frequency of CDKN2A pathogenic variants and of the MC1R R160W variant. Melanoma in children (≤12 years) had more frequently spitzoid histotype, were located on the head/neck and upper limbs and had higher Breslow thickness. The MC1R V92M variant was more common in children than in adolescents. CDKN2A common polymorphisms and MC1R variants were associated with a high number of nevi. CONCLUSION: Our results confirm the scarce involvement of the major high-risk susceptibility genes in paediatric melanoma and suggest the implication of MC1R gene variants especially in the children population.

Merkel cell carcinoma and HIV infection: a case report and review of the literature.

Merkel cell carcinoma (MCC) is a skin cancer of neuroendocrine origin that occurs most often in sun-exposed areas. In the general population, it is a disease of older adults, with only 5% of cases occurring below the age of 50 years. Immunosuppression is the significant risk factor for the development of MCC and recently it was suggested that individuals with HIV have a relative risk of 13.4 to developed MCC in comparison with the general population. We report a case of MCC in an HIV-infected patient and we review nine patients with HIV with MCC. Our patient was a 54-year-old man who came to our attention without a known HIV diagnosis. He was apparently in good health and had no risk factor for HIV, but by the atypical site of the lesion and by the relative young age of the patient we suspected a case of immunosuppression and for this reason we did HIV test that had a positive result. The patient was treated with surgery and chemotherapy but died as a result of liver metastases 25 months after his tumor was diagnosed.

Non-specific influx of T-cell receptor alpha/beta and gamma/delta lymphocytes in mucosal biopsies from a patient with orofacial granulomatosis.

Orofacial granulomatosis (OFG) represents an inflammatory disorder of the facial and oral mucosa, histologically characterized by non-caseating epithelioid cell granulomas. Since other granulomatous diseases have been shown to be characterized by a limited heterogeneity of alpha/beta and gamma/delta T cells, we investigated the T-cell diversity of both types of lymphocytes obtained from the same OFG patient. When we compared the T-cell receptor diversity of the lymphocytes accumulating at the site of the lesions with that of the peripheral blood counterpart, we did not find significant differences. Furthermore, no exclusive expansions of different T-cell clones were seen in the patient. From these data we conclude that, in this OFG patient, the majority of T cells have no specificity for a single or for a few antigens and that tissue accumulation of T lymphocytes is the result of a random influx of cells at the site of inflammation.

Sentinel node biopsy in melanoma: the experience of Brescia Civic Hospital.

The accuracy of the sentinel node (SN) technique in the evaluation of lymph node involvement in melanoma was evaluated in 71 consecutive patients with localized disease and Breslow index >1 mm. Lymphoscintigraphy identified at least one SN in 70 of the 71 patients (98.5%). The following day 69 patients underwent selective SN excision. The SN was identified by portable probe. One hundred and twenty-two lymph nodes were removed, 14 (11.4%) of which were metastatic in 9 patients (13%). No metastases were found in 40 patients with Breslow <2 mm. Eight of the 9 patients with positive SNs underwent lymphadenectomy of the whole basin and in two patients new metastatic nodes were found. At 4-26 months' follow-up 1 of the 60 patients with negative SN (scalp melanoma with Breslow 6.2 mm) developed bilateral cervical metastatic nodes. Two more patients with Breslow 3.7 and 5 mm, respectively, developed liver and lung metastases. The remaining 57 patients are still disease free. Among the 9 patients with tumor-positive SNs, 1 was lost to follow-up, 3 died and 5 are still alive. Our data confirm the clinical reliability of the SN technique in melanoma; we feel the technique should be considered a standard tool in the evaluation of melanoma patients.

Nonlymphoid intraepidermal mononuclear cell collections (pseudo-Pautrier abscesses): a morphologic and immunophenotypical characterization.

We evaluated the incidence, morphology, and immunophenotype of intraepidermal collections of mononuclear cells (ICMC) in a large number of inflammatory dermatosis and cutaneous lymphomas. ICMC appeared as small to large aggregates of cells, showing a morphology variable from monocytes to obvious dendritic cells, admixed with rare lymphocytes. ICMC were recognized in the epidermis or within hair follicle epithelium, and were either loosely or compactly arranged. ICMC were identified in 124 of 1,248 skin biopsies (9.9%) of inflammatory or lymphoid infiltrates, and were particularly frequent in spongiotic (43.4%) and in lichenoid dermatitis (10%), whereas they were rarely found in nonspecific superficial dermatitis (3.8%) and in psoriasis (4.7%). ICMC were also frequent in cutaneous T-cell lymphoma (13.3%), where they mimicked Pautrier abscesses. The ICMC forming cells showed a unique phenotype: the majority of them expressed CD1a and S-100, and lacked CD14, similar to mature Langerhans cells, but they were also strongly labeled by anti-CD11b, anti-CD36, and anti-CD68. Moreover, a subpopulation of them expressed CD83, an antigen that is usually absent on Langerhans cells. The occurrence of ICMC is a rather frequent, although hitherto poorly studied, phenomenon, occurring in several dermatosis, but particularly frequent in spongiosis-associated skin reactions. The cells within ICMC are represented by dendritic cells and dendritic cell precursors, whose phenotype indicates their derivation from circulating monocytes and differentiation into mature Langerhans cells.

Persistence of human T cell lymphotropic virus type 1 (HTLV-1) sequences in peripheral blood mononuclear cells from patients with mycosis fungoides.

Mycosis fungoides (MF) is a rare form of cutaneous T cell lymphoma suspected of having a viral etiology. As in adult T cell leukemia, the virus involved may be human T lymphotropic virus type 1 (HTLV-1). We cultured the peripheral blood mononuclear cells (PBMC) of 29 patients with MF HTLV-1 seronegative by enzyme-linked immunosorbent assay and Western blot. The presence of reverse transcriptase (RT) and p24 antigen was investigated in the concentrate supernatant of the culture. The DNA of all studied patients was submitted to polymerase chain reaction and Southern blot analysis using primers and probes recognizing the tax region of HTLV-1/2 and the pol region of HTLV-1. 10 of 29 patients were found positive to HTLV-1, whereas they were always negative to RT and p24. The same results were confirmed in double blind after 6 mo. Our findings suggest HTLV-1 may be involved in the etiology of MF, at least in certain cases.