Faculty Bibliography

BACKGROUND: One-third of melanomas in Puerto Ricans occur on the skin of palms and soles. This is a study to define the characteristics of melanocytic nevi in those locations. METHODS: A sample of 1,039 patients were randomly examined for pigmented macules on the palms and soles. After informed consent, biopsies of these lesions were done on 67 patients. RESULTS: Among the patients, 13% were found to have pigmented macules on the palms and soles. Volar melanocytic macule was the most frequent lesion. CONCLUSIONS: Melanocytic nevi occur frequently on volar skin. The criteria for removal of these lesions should not be different from those lesions at other locations.

Solar lentigines ("liver spots") commonly occur on sun-damaged skin in the elderly population. Although they are benign, it is difficult in practice to distinguish solar letigines and junctional nevi from melanoma in situ. We report a patient who developed melanoma on the same site as a previously diagnosed solar lentigo. We also review the histopathological criteria for differentiating these benign lesions from potentially malignant ones.

Evidence is presented that the high levels of internal L-glutamic and L-aspartic acid in frog (Rana esculenta) red blood cells are due to the existence of a specific carrier for acidic amino acids of high affinity (Km = 3 microM) and low capacity (Vmax 0.4 mumol L-Glu.Kg-1 dry cell mass.10 min-1). It is Na+ dependent and the incorporation of L-glutamic acid can be inhibited by L- and D-aspartate and L-cysteic acid, while D-glutamic does not inhibit. Moreover, this glutamic uptake shows a bell-shaped dependence on the external pH. All these properties show that this carrier belongs to the system X-AG family. Besides the incorporation through this system, L-glutamic acid is also taken up through the ASC system, although, under physiological conditions, this transport is far less important, since it has relatively low affinity (Km 39 microM) but high capacity (Vmax 1.8 mumol L-Glu.Kg-1 dry cell mass.10 min-1).

BACKGROUND: Infiltration of commonly used local anesthetics is painful. It has been speculated that the pain on infiltration is a direct consequence of the acidity of the anesthetic solution. OBJECTIVE: To compare the degree of pain of intradermal infiltration and the duration of anesthesia for 1% lidocaine with epinephrine 1:100,000, 1% lidocaine with epinephrine 1:100,000 with 80 meq/L sodium bicarbonate, bacteriostatic saline solution with 1% lidocaine with epinephrine 1:300,000, and bacteriostatic saline solution with 1% lidocaine with epinephrine 1:100,000. METHODS: The study was performed in three phases: 1) double-blind comparison study, 2 and 3) open clinical trials. RESULTS: Bacteriostatic saline solution with epinephrine 1:300,000 is significantly less painful on intradermal infiltration than lidocaine with epinephrine 1:100,000 with sodium bicarbonate 80 meq/mL. The saline preparation is an effective anesthetic alternative for superficial surgical procedures such as shave and scissors excision, light curettage and electrodesiccation, and superficial CO2 laser vaporization. CONCLUSION: The pH values of bacteriostatic saline solution with epinephrine 1:300,000 and lidocaine with epinephrine diluted with bacteriostatic saline solution are 5.3 and 4.2, respectively. Both were found to be less painful than 1% lidocaine with epinephrine with sodium bicarbonate 84 meq/mL, which had a pH of 7.4. It is unlikely that the pain of infiltration is a simple function of the pH of the anesthetic solution.

BACKGROUND: Tattooing with iron oxide pigment is used to create a permanent line along the eyelid margins and to cause permanent pigmentation of the eyebrows. However inflammatory sequelae can occur. OBJECTIVE: To present the development and treatment of a granulomatous inflammation as a sequela of iron oxide tattooing in the eyebrows. METHOD: A skin biopsy was performed, Histopathologic examination revealed deposits of reddish-brown pigment and a superficial dermal infiltrate consisting of lymphocytes and giant multinucleated cells (Langhan's and foreign body). RESULTS: A patient developed a granulomatous reaction to iron oxide after undergoing permanent pigmentation of the eyebrows. Treatment with systemic and topical steroids resulted in marked improvement at 6-month follow-up. CONCLUSIONS: This is an unusual complication. A skin test should be performed on any patient who is to undergo tattooing with iron oxide pigment.

BACKGROUND: While significant risk factors for malignant melanoma may initially develop or are first seen in childhood, the actual occurrence of this neoplasm in prepubertal children is uncommon. METHODS: A retrospective study of malignant melanoma in Puerto Ricans up to 16 years of age occurring from 1973 to 1990 was carried out by identifying those cases in the Puerto Rico Cancer Registry. RESULTS: A total of seven cases were found consisting of three boys and four girls with ages ranging from 22 months to 16 years and comprising 0.94% of the total melanomas. In three of the seven cases, there was a history of a previously existent small congenital melanocytic nevus on the area. Three cases were Clark's level I, two level II, and in two cases with proved metastatic disease, Clark's level of invasion were not reported. Those cases with Clark's level I and II had a 100% 5-year survival. CONCLUSIONS: Although rare, malignant melanoma in children can be as aggressive as in adults. Among the known factors predisposing to malignant melanoma, three out of seven cases developed within a small congenital nevus, two of which occurred during the first decade of life. Due to the rarity of this event in our population, it appears unreasonable to excise all small congenital nevi during the first decade of life. Even for those who advocate excision of all small congenital nevi, the evidence at present suggests that such small nevi very rarely undergo malignant change before puberty and therefore a policy of observation in childhood and offering excision around the time of puberty is perfectly logical.