Really synchronous cutaneous melanomas: serendipity or need for prevention?

ARTICLE

Auteur(s) : Roberto Betti¹, Lorenzo Gualandri¹, Raffaella Vergani¹, Silvano Menni¹, Carlo Crosti²

¹Università degli Studi di Milano Clinica Dermatologica AO San Paolo Via A. di Rudinì 8, 20142 Milan, Italy
²Università degli Studi di Milano. Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena -Clinica Dermatologica Fondazione IRCCS di Natura Pubblica

Synchronous melanomas are a particular subgroup of multiple primary melanomas, (MPM), in which two or more tumours are detected simultaneously.

We report three patients with synchronous melanomas. The first was a 64-year-old man with two melanomas on his dorsal region (figure 1A): a superficial spreading melanoma with incipient vertical growth Clark level IV and 2.99 mm Breslow thickness on his left scapular region (figure 1B) and a melanoma Clark level IV with 1.47 mm Breslow thickness on his right dorsal lesion (figure 1C). After lymphoscintigraphy, histological examination of the sentinel lymph in his right armpit was negative.

The second patient was a 71-year-old bald man with a superficial spreading melanoma, Clark level III, 0.80 mm Breslow thickness, on the back and a lentigo maligna in situ on the head.

The third, 71-year-old patient had a lentigo maligna melanoma in situ on the back and a melanoma in situ on the shoulder, respectively. About 1 year after the first, another lentigo maligna melanoma in situ was removed from his back. The first and the second patients had several common nevi, the first had more than five clinically atypical nevi. No patient had a family history of melanoma. After more than 2 years of follow up, no apparent metastases were identified in any patient.

The frequency of MPM is probably underestimated because case-control studies have rarely been performed [1] and follow-ups are too brief. The estimated risk for the occurrence of a further primary melanoma has been estimated as ranging from 8.5 [2] to 12.7% [3]. Knowledge of risk factors for patients with MPM is important in order to perform a correct clinical follow up. Risk factors include [2, 4]: a personal history of melanoma, genetic or familial factors, male gender, presence of atypical and familial nevi, younger age, a history of significant sun exposure. More than two primary melanomas are possible, although with lower frequency. For most patients, subsequent melanomas seem to be shallower than the initial one [1, 4]. The localization of the second melanoma tends to be on a site different from the initial tumour in an high percentage of cases [1, 4]. However, a body concordance higher than expected by chance for second melanoma was observed [5], so suggesting a field effect of susceptibility for some anatomical areas.

According to Johnson [4], the concurrent diagnosis of synchronous melanomas is considered when a second melanoma is diagnosed within one month. Interestingly, Carli et al. [6] observed that this time represents a diagnostic delay with obvious implications. We agree with them and think that the term synchronous melanoma has to be applied only for melanoma diagnosed or suspected during the same first observation.

Our three reported patients have really synchronous melanomas, diagnosed or suspected during the same observation. In the first patient both melanomas were in the same regional area. Patients 1 and 2 had several nevi, of which many were atypical. Patient 2 developed his second melanoma on an area totally different from the first one.

Patient 3 developed a third melanoma in the same regional area 1 year after the first diagnosis. It is possible that frequent past sunburns have had a late manifestation of a field effect susceptibility.

These observations further stress the importance of a careful examination of the whole body surface especially in the presence of multiple common and atypical moles. Psychological factors and lesion perception are involved in the diagnosis of melanoma. The unconscious lowering of the physician’s alertness following the first melanoma diagnosis may lead to disregarding the possibility of another melanoma.

Serendipity does not apply in cases of synchronous melanomas, but prevention does, because the chance of a further tumour is very possible. We think that a long period of follow up is recommended for these patients.

Acknowledgements

References

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5 Giles G, Staples M, McCredie M, Coates M. Multiple primary melanomas.an analysis of cancer registry data from Victoria and New South Wales. Melanoma Res 1995; 5: 433-8.

6 Carli P, DeGiorgi V, Chiarugi A, et al. Multiple synchronous cutaneous melanomas: implications for prevention. Int J Dermatol 2002; 41: 583-5.