ISSN 0970-4388

Oral Melanotic Macule - A Case Report PAIS Sa, HEGDE S Kb, BHAT S SC

ABSTRACT

A melanotic macule is a benign pigmented lesion of oral cavity characterised by increase in melanin pigmentation. Presented here is a case report of 12 year old girl with black pigmented area on right buccal mucosa. An exciscon biopsy was done which confirmed the diognosis by as melanotic macule.

Key Words Differential diagnosis, Etiology, Histopathology, Management, Melanotic mecule.

INTRODUCTION

The term melanotic macule has been used to describe a benign pigmented lesion of the oral cavity, characterized by an increase in melanin pigmentation along the basal cell layer of the epithelium and the lamina propria. The melanotic macule is typically a well circumscribed flat area of pigmentation that may be brown, black, blue or grey in colour. Most of the lesions are less than 1 cm in diameter, although in occasional cases they may be larger in size. The solitary oral melanotic macule is seen in middle aged adults. Females are more affected than males. The oral melanotic macule is usually located on the vermilion border of the lips and termed as the labial melanotic macule. Intraorally, it may be found on the gingiva, buccal mucosa or the palate and is termed as the oral melanotic macule. 1,2,3 Treatment usually consists of surgical excision, and a biopsy to rule out the possibility of an early malignant melanoma. Periodic evaluation may be necessary to assess any clinical changes. 4 There is a paucity of literature concerning this lesion in children.

CASE REPORT

A12 year old girl reported to the Department of Pedodontics, Yenepoya Dental College Mangalore with the chief complaint of black pigmented area on the right buccal mucosa, that kept on increasing in size since one year (Fig. 1). The family history did not reveal any such occurrences. Intra

a. Assistant Professor, b. Associate Professor, c. Professor and Head Department of Pediatric Dentistry, Yenepoya Dental College, Mangalore.

oral examination revealed a well circumscribed bluish black area of pigmentation which was firm in consistency, elliptical in shape and measuring about 1.0x0.5x0.1 cms. It was not associated with pain or any other signs of inflammation. Excision biopsy was done and the specimen was sent (Fig.2) for histologic examination. Biopsy report showed a mild degree of parakeratosis in the stratified squamous epithelium (Fig. 3). Melanin pigment could be identified in both the basal cell layer and the lamina propria. Although it was difficult to evaluate the amount of found to be more in the basal cell layer. Proliferation of capillaries and fibroblasts was also observed. The patient was recalled after one week and after six months. There were no signs of recurrence.

DISCUSSION

There is very little information in literature about the brown or black melanotic lesions of the oral mucosa, that are not a manifestation of racial pigmentation and are not associated with other syndromes. These melanotic macules have been variously termed as ephelis, melanosis, lentigo, solitary labial lentigo, labial melanotic macule and oral melanotic macules.3

Buchner and Hansen analyzed 105 cases of oral melanotic macule and found that in most of the patients, melanotic macule was a solitary lesion and the most likely location was the vermilion border, followed by the gingiva. George et al, conducted a review of 353 cases of oral melanotic macule4. They concluded that mean age of occurrence of oral melanotic macule is 43.1 years with significant predilection for female. Oral melanotic macule was located on lower lip. The most oral melanotic macules were Brown in colour and the mean size of the lesion was about 6.8 mm. Regarding etiology, melanotic macules may result from racial pigmentation, endocrine disturbance, antimalarial therapy, Peutz-Jeghers syndrome, trauma, hemochromatosis, or chronic pulmonary disease, or they may be idiopathic. Majority of these require clinicopathologic correlation for definitive diagnosis. In these instances, the diagnosis should reflect the etiology (for example, melanin pigmentation secondary to trauma). For those lesions without an

J Indian Soc Pedo Prev Dent June (2004) 22 (2) 73 - 75

Oral Melanotic Macule

identifiable etiologic factor, the term oral melanotic macule has been suggested2. In the literature, the oral melanotic macule has been given various inappropriate and erroneous names, such as ephelis5,6 and lentigo7,8. Ephelis (freckle) is a circumscribed brown macule over skin that has been exposed to sunlight. Histologically, ephelis shows increased melanin pigmentation in the basal-cell layer without an increase in the number of melanocytes3. Ephelides are not found on mucous membranes. Although the histologic appearance of the melanotic macule of the oral mucosa is similar to that of ephelis of the skin, it is not at all related to exposure to sun and thus the term ephelis for the intraoral lesion is a misnomer. The term lentigo has also been suggested for oral melanotic macules. But since melanotic macules of the oral mucosa do not exhibit a significant increase in the number of melanocytes, the term lentigo is not considered appropriate for this type of lesion.

Weather et al1 and Page et al2, recently introduced the terms labial melanotic macule for lesions on the vermilion border and oral melanotic macule for lesions within the oral cavity. The term melanotic macule should be reserved for lesions in which there is a clinicopathologic correlation between the clinical feature of a discrete pigmented macule and the histologic feature of hyperpigmentation of the basal-cell layer and / or the lamina propria3. The term focal melanosis should be used as a histologic designation when hyperpigmentation of the basal-cell layer and/or the lamina propria is associated with clinically nonpigmented pathologic conditions3. Regarding histopathology, the dark colour of the lesion is due to increase in melanin pigment of the basal cell layer, not from an increased number of melanocytes. Melanin may also be found in the lamina propria. Further histologic criteria are absence of elongated rete ridges and lack of prominent melanocytic activity. If there is an elogation of rete ridges, a heavily pigmented basal cell layer, and an increase in the

Fig: 1 Intra oral photograph showing Melanotic Macule in the Right Buccal Mucosa

Fig: 2 Post- operative Intra oral photograph after the excision of Oral Melanotic Macule.

Fig: 3 Histo-pathologic features suggestive of Oral Melanotic Macule.

J Indian Soc Pedo Prev Dent June (2004) 22 (2) 74

Oral Melanotic Macule

number of normal-appearing basal layer melanocytes, a junctional nevus has to be considered. If the melanocytes show proliferation, atypia, and some irregularity in their arrangement, the histopathologic diagnosis is atypical melanocytic hyperplasia, which may correspond clinically to early malignant melanoma (melanoma in situ)9. In our case, we found melanin in both the basal cell layer and the lamina propira. This agrees with the study conducted by Buchner and Hansen3. Page et al2 found that 30% of their cases had melanin only in the basal cell layer and 3.8% only in the lamina propria2. The small size, slow growth rate, and flat clinical appearance favour a benign diagnosis. Oral melanotic macule has to be differentiated from certain other similar conditions exhibiting hyperpigmentation. Racial pigmentation is generally diffuse, is genetically acquired and seen at birth. It is more common in Caucasians and has been termed as oral melanosis. The two most important causes of post inflammatory hyper pigmentation are lichen planus and lupus erythematosis. There are certain endocrinal hyper pigmentations. Addison's disease causes a darkening of the oral mucosa which is irregular, patchy and found on the gums. Metal deposition can cause discolouration either from copper as in Wilson's disease or from amalgam as in an amalgam tattoo. It could be associated with syndromes as in Peutz Jeghers syndrome where freckles are seen not only in the oral cavity, but also at the distal extremities, Leopard syndrome where pigmentation is seen all over the body. Antimalarial drugs like chloroquine can also cause muscosal hyperpigmentation which also occurs on other body parts like the shinns. The treatment of oral melanotic macule is debatable5. Although the lesion is completely benign2 and shows no tendency to recur or to become malignant, sometimes it is difficult if to distinguish it cliniclly from other pigmented lesions, such as nevus, malignant melanoma in situ, and incipient malignant melanoma. Thus, complete excision of oral melanotic macule is indicated and histologic examination or at least be checked at frequent intervals for any change in size, shape, or colour. This is especially necessary for lesions of the palate - a location for which oral malignant . melanoma has a strong predilection10.

Melanotic lesions having a duration of fewer than 5 years, which have exhibited changes in size or colour or which exhibit tumefaction, ulceration, or bleeding, should be excised. Lesions with reliable history of more than 5 years without change in character in which a known cause seems evident (trauma, etc.), may be followed or excised, although we prefer the latter.

REFERENCES

1. Weathers D. R., Corio. R. L, Crawford B. E., Giansant J. S. and Page. L. R. : The labial melanotic macule. Oral Surg Oral Med Oral Pathol 1976 ; 42 : 196 - 205

2. Page L. R., Corio R. L., Crawford B. E., Giansant J. S. and Weathers D. R. : The oral melanotic macule. Oral Surg Oral Med Oral Pathol 1977 ; 44: 219 - 226

3. Buchner A. and Hansen L. S. : Melanotic Macule of the oral mucosa. Oral Surg Oral Med Oral Pathol 1979 ; 48 : 244 - 249.

4. George E. K., Andrew P. H., William T. R., Louis M. A. and John A. S. : Oral Melanotic Macule - A Review of 353 cases. Oral Surg Oral Med Oral Pathol 1993 ; 76 : 59 - 62

5. Trodohl J. N. and Spragul W. G. : Benign and Malignant Mucosa, an Analysis of 135 cases. Cancer 1970 ; 25 : 812 - 823

6. Bhaskar S. N.: Oral Lesions in the Aged population - a survey of 785 cases. Geriatrics 1968 ; 23 : 137 - 149

7. Beeker S. W. Jr. : Pigmentary Lesions oral melanotic macule on to the skin and oral cavity. Oral surg 1969 ; 28 : 526 -533.

8. Shapiro. L. and Zegarelli D. J. : The solitary Labial Lentigo - a clinicopathologic study of 20 cases. Oral surg 1971 ; 31 : 87 - 92

9. Bork. K., Hoede. N., Korting. G. W., Burgdorf. W. H. C. and Young S. K. : Diseases of the oral Mucosa and the Lips. 2nd Edition, W. B. Saunders Company, 1996 ; 310 - 312

10.Chaudhary A. P., Hampel A. and Gorlin R. L. : Primary Malignant Melanoma of the Oral Cavity-a Review of 105 cases. Cancer 1958 ; 11 : 923 - 928

11.Bengel W., Veltman G., Loevy H. T. and Pierangelo T. : Differential Diagnosis of Diseases of the Oral Mucosa. Quintessence Publishing Co., Inc., Chicago / Illinosi / 1989 : 153 - 201

Reprint Requests to : Dr. Sham Bhat Head of the Department of paediatric Dentistry, Yenepoya Dental College, Kodialbail, Mangalore, Karnataka, INDIA.

J Indian Soc Pedo Prev Dent June (2004) 22 (2) 75