Case report: malignant melanoma arising during drug therapy for vitiligo

The Double Strike Hypothesis of the vitiligo pathomechanism: new approaches to vitiligo and melanoma

Based on current research, we present a consolidated set of theses which explain the pathomechanisms of vitiligo- and melanoma-associated hypopigmentation. The main thesis is the Double Strike Hypothesis, i.e. vitiligo is caused by at least two different major pathomechanisms: an antibody-based pathomechanism and a T-cell-based pathomechanism. The antibody-based pathomechanism is dominant in diffuse vitiligo, while the T-cell based pathomechanism is dominant in localised vitiligo. Based on this main thesis we derive new therapeutical approaches to vitiligo and melanoma by using the different pathomechanisms. Finally we explain why melanoma-associated hypopigmentation as a natural immunotherapy is still in statu nascendi.

Vitiligo treatment options: An evolving scenario

Sequential displays of several treatment options for vitiligo have been scanned from the literature, and are presented here. A few of the medical modalities have been resigned to history, whereas others have become customary in clinical practice. There has also been a recent surge of interest in the surgical treatment of this disease. Accordingly, this has been appraised and summarized. Special attention has been given to prevalent medical modalities so that they may be effectively utilized by those currently in practice.

Phototherapy of posterior uveal melanomas

The results of phototherapy on a small series of 19 patients with uveal melanomas are presented. Laser radiation at a wavelength of 620 to 630 nm was used in conjunction with a 5 to 7.5 mg/kg dose of haematoporphyrin derivative administered 24 hours before treatment, with total doses/treatment averaging 960 J/cm2. Eleven patients received two treatments, and one received a third. The longest duration of tumour control to 30 September 1990 was 31 months. Of the 19 patients treated six had complete regression of the tumour, while another five had minor to significant regression. A strong correlation between degree of regression and degree of tumour pigmentation was found, the lighter tumours responding much better than darker tumours. There were also strong indications that if a tumour did not respond to the initial phototherapy it was very unlikely that subsequent phototherapy would provide any further benefit.

Possible ultraviolet A-induced lentigines: a side effect of chronic tanning salon usage

A patient who developed lentigines after prolonged ultraviolet A (UVA) exposure in a tanning booth is described. The patient had no exposure to psoralens or furocoumarins. Histologic examination of a representative lentigo revealed melanocytic hyperplasia and cytologic atypia. Increased nevocytic activity with histologic dysplasia was present in several junctional nevi excised during the period of UVA exposure. Several studies have revealed significant effects of UVA on melanocytes. Patients should be cautioned to avoid tanning bed use in view of these potentially deleterious effects.

Cutaneous melanomas in patients treated with psoralens plus ultraviolet A. A case report and the experience of the PUVA Follow-up Study

Psoralens plus ultraviolet A (PUVA) therapy is widely used in the treatment of psoriasis and other cutaneous conditions. We present the case of a patient who developed a superficial spreading melanoma 3 years after first being treated with PUVA. The development of melanomas in patients receiving PUVA is reviewed. During 13,224 person-years of prospective follow-up of 1380 patients enrolled in the PUVA follow-up study, three melanomas were diagnosed, which does not differ significantly from the expected rate (relative risk = 1.5 with 90% confidence interval 0.3 to 7.3). However, considering the effects of PUVA on melanocytes and that the development of melanomas may have a long latent period, continued follow-up studies are indicated.

Phototherapy with argon lasers and Rhodamine-123 for tumor eradication

The effectiveness of Rhodamine-123 (Rh-123) as a new photochemosensitizing agent for the argon laser treatment of human melanoma and squamous carcinoma cells in vitro was recently demonstrated. In this study, a new technique of "rosette" treatment with the argon laser was developed to completely eradicate human squamous carcinoma (P3) tumor transplants in nude mice after chemosensitization with Rh-123. Each group included four nu/nu mice injected subcutaneously with 10(7) P3 carcinoma cells/site for a total of 48 sites. Tumor take was greater than 95% at one week, with greater than 10 mm3 tumor volume at each site. Test groups were sensitized with Rh-123 (1 microgram/ml for 1 hour) by intratumor or intraperitoneal injection at 1 week and then treated with the argon laser at 514.5 nm. To allow uniform delivery of energies to the tumor and its edges, a new "rosette" technique was developed. The tumors were then exposed to nonthermal levels of 700 J/cm2 (36 degrees C) or 950 J/cm2 (40 degrees C) as determined by a new and reproducible method of dosimetry. All 16 tumors in this test group showed complete regression with excellent wound healing at 2 weeks and no recurrences, even after an 8 week followup. These results demonstrate that effective eradication of tumors can be achieved in vivo only after sensitization with Rh-123 and specific argon laser treatment ("rosette"), even at nonthermal levels of energies. The high effectiveness of this technique and low toxicity of Rh-123 may render its clinical use very attractive for the treatment of superficial malignancies.

The effects of argon lasers on human melanoma cells sensitized with rhodamine-123 in vitro

A human melanoma cell line, M14, was first exposed to a nontoxic dose of Rhodamine-123 (1 microgram/ml) for one hour, then subjected to a treatment with a single mode argon laser at 514.5 nm. The temperature and energy levels delivered to the target cells were determined by a reproducible method of dosimetry. Cell viability was assessed by the Trypan Blue exclusion test. Cell duplication and DNA synthesis were measured by the incorporation of 3H-thymidine at 6 and 24 hours post-treatment. At energy levels and temperatures higher or equal to 950 J/cm2 (40 degrees C), an immediate suppression of DNA synthesis was accompanied by nonviability of the M14 carcinoma cells. At energy levels between 130-900J/cm2 corresponding to temperatures between 28 to 39 degrees C, both an immediate and delayed inhibition of DNA synthesis was noted but the cells remained viable. The results indicate that Rhodamine-123 at nontoxic doses of 1 microgram/ml enhances the tumoricidal effects of the argon laser at reduced temperatures as low as 40 degrees C. Furthermore, at physiological temperature ranges as low as 28 to 30 degrees C, an immediate inhibition of cell duplication was demonstrated while cell viability was not affected. These observations suggest that Rhodamine-123 can be used effectively as a chemosensitizing agent in the treatment of human tumor cells with the argon laser at 514.5 nm.

Psoralen photochemotherapy

Psoralens and sunlight have been used by the Egyptians and Indians for hundreds of years for the treatment of vitiligo. The combination of oral psoralens and artificial ultraviolet A (PUVA) therapy was approved for the management of severe psoriasis by the Food and Drug Administration in 1982. Since then PUVA therapy has been found to be an effective modality in the treatment of many cutaneous conditions. When properly administered, the major short-term side effects are minimal. The long-term side effects may include an increased risk of squamous cell carcinoma, atypical cutaneous pigmentation, accelerated skin aging, and ophthalmologic abnormalities. By careful patient selection and limiting the cumulative UVA dosage and frequency by using combinations or alternative therapies, these side effects may be reduced. Continued reporting of carefully carried out long-term prospective studies will provide us with more knowledge of the long-term side effects of PUVA. In the meantime, for each patient on PUVA therapy the risk/benefit ratio should be carefully considered.

UVA-induced melanocytic lesions

The occurrence of melanocytic lesions following PUVA therapy is well documented. We describe a patient who developed similar lesions after cosmetic use of a home sun-bed without psoralen administration. Histological examination showed increased numbers of large and sometimes atypical melanocytes, which may theoretically act as precursors for melanoma.

Cutaneous and ocular side-effects of oral photochemotherapy: results of an 8-year follow-up study

To determine the long-term cutaneous side-effects of oral photochemotherapy (PUVA), we examined 95 patients, 59 with psoriasis and 36 with mycosis fungoides (MF). These comprised 80% and 69% respectively of the patients with these disorders treated with PUVA in our department from 1977 to 1985. Two psoriatic patients had squamous carcinomas, both of whom had received high cumulative UVA doses and also methotrexate concurrently with PUVA. Six patients with MF had actinic keratoses. The mean age of these patients (69 years) was significantly greater than the mean age of the patients without actinic keratoses (54 years), but there was no significant difference in their cumulative UVA doses. No patients developed basal cell carcinomas or malignant melanoma. 'PUVA lentigines' were found in 46% of the patients. They were most frequent in patients currently being treated and in those who had received high cumulative UVA doses, but persisted for up to 7 years after discontinuing therapy. Seventy-one patients had yearly ophthalmological examinations, or a single examination at least 3 months after commencing PUVA. This examination included retinal function tests to detect any subclinical visual impairment. Five of these patients had cataract prior to PUVA therapy, and were significantly older (mean age 71 years) than those without cataract (mean age 53 years). Three patients (mean age 61 years) developed new lens opacities whilst receiving PUVA. However, none of these patients was considered to have cataract as none had impairment of visual acuity due to lens opacity. No patients without lens opacity developed evidence of subclinical visual impairment.

Malignant melanoma in situ in two patients treated with psoralens and ultraviolet A

Two patients are reported who were treated with 8-methoxypsoralen and ultraviolet A (PUVA) for psoriasis and developed cutaneous lesions of malignant melanoma in situ (atypical melanocytic hyperplasia). One patient received 324.5 joules/cm2 of UVA. Seven months after discontinuing therapy, he developed a superficial spreading melanoma in situ in association with an intradermal nevus on the left posterior thoracic area. The second patient received 2,802 joules/cm of UVA. While on PUVA therapy she developed an in situ lentigo melanoma on her lower lip. To our knowledge only one other psoriatic patient and one patient with vitiligo have developed malignant melanomas after PUVA therapy, so that an increased incidence of malignant melanomas after PUVA therapy, so that an increased incidence of malignant melanoma following PUVA is not documented.

Malignant melanoma and vitiligo-like leukoderma: an electron microscopic study

We report clinical and ultrastructural results in eight patients with melanoma and widespread leukoderma. Leukoderma appears to be a good prognostic sign. Although some features of this entity are suggestive of vitiligo, the patients' age, the distribution and appearance of body lesions, and ultrastructural results show a more varied clinical and ultrastructural spectrum. The high frequency of ocular pigmentary disturbances and uveitis in this patient population is noteworthy and deserves further study. We would recommend routine use of Wood's light examination in following patients with thick stage I, stage II, or stage III melanoma to facilitate detection of this phenomenon.