Unilateral Nevus of Ota with Bilateral Nevus of Ito and Palatal Lesion: A Case Report with a Proposed Clinical Modification of Tanino's Classification.

Nevus of Ota and nevus of Ito are rare dermal melanocytoses. Nevus of Ota may be very rarely associated with the nevus of Ito and other extra cutaneous features. Both nevi are similar in all respect apart from the area of distribution. Bilateral distribution of nevus of Ito is seldom reported in the literature. A 24-year-old male patient reported with nevus of Ota of the right side of his face since his infancy and nevus of Ito on both shoulder regions since early childhood. He had bluish lesions on the right side of his hard palate. Systemic examination was normal. Relevant laboratory investigations were non contributory. The histopathological examination of the skin from the affected areas showed the presence of elongated dendritic dermal melanocytes. The present case is the first report of an association of bilateral nevus of Ito with nevus of Ota and palatal lesions. Tanino classified Nevus of Ota into four groups. As both the nevi are similar in all respect except the area of distribution, a minor modification of the existing Tanino's classification to incorporate the nevus of Ito into the classification for the Ota's nevus may be appropriate.

What was known?

1. Nevus of Ota is a dermal melanosis occurs more frequently in females.

2. Nevus of Ota may occur simultaneously with nevus of Ito.

3. Tanino introduced a classification system for nevus of Ota. There is no such classification for the nevus of Ito.

Introduction

Dermal melanocytoses comprise of a group of benign pigmented lesions characterized histologically by the presence of melanin-producing dendritic melanocytes within the dermis. Nevus of Ota, nevus of Ito, mongolian spot, and dermal melanocyte hamartoma are the morphological forms of dermal melanosis.[1] Nevus of Ota is usually a unilateral, patchy dermal melanosis that affects the skin of the face along the distribution of the ophthalmic and maxillary divisions of the trigeminal nerve.[2] It usually involves the periorbital region, the temple, the forehead, the malar area and the nose. In about two third cases the ipsilateral sclera is affected with a bluish discoloration.[3] Hulke in 1861 first described oculodermal melanosis and in 1939 Pusey observed the condition in a Chinese student. In 1939 Masao Ota gave a descriptive name of the condition as nevus fuscocaeruleus ophthalmomaxillaris and thereafter the condition was popularly known as nevus of Ota.[4] Nevus of Ota occurs more commonly in Asians and blacks though cases in whites have also been reported.[5] Females are affected five times more than the males.[6] The onset is usually at birth but may appear at puberty in a small percentage of cases.[7] The intensity of the lesion may be influenced by the onset of puberty, fatigue, menstruation, insomnia and even weather.[68] The typical lesion is unilateral though bilateral involvement may occur.[9] The extracutaneous lesions may occur in sclera, cornea, eyelids, retina and other sites like tympanum (55%), nasal mucosa (30%), pharynx (25%), palate (20%) etc.[510] A number of classifications have been suggested depending on different parameters and utility.[111213] The classification laid down by Tanino in 1939 has remained the most useful clinical classification and in this classification nevus of Ota has been classified into four major subtypes:[14]

Type-I

IA: Mild orbital type-Distribution over the upper and lower eyelids, periocular and temple region.

IB: Mild zygomatic type-Infrapalpebral fold, nasolabial fold and zygomatic regions are affected.

IC: Mild forehead type-Only forehead is affected.

ID: Ala nasi alone is affected.

Type-II

Moderate type-The lesions affect upper and lower eyelids, periocular, zygomatic, cheek and temple regions.

Type-III

The condition is distributed over the scalp, forehead, eyebrows and nose.

Type IV

Bilateral type

Nevus of Ito, also known as nevus fuscocaeruleus acromiodeltoideus is another dermal melanosis. This usually manifests as unilateral, asymptomatic, blue, gray or brown lesions.[15] It was first described by Minor Ito in 1954.[16] Nevus of Ito differs from the nevus of Ota only by its area of distribution and rarity. It affects the area of distribution of the posterior supraclavicular and cutaneous brachii lateralis nerves that encompass the supraclavicular, scapular or deltoid regions.[5] Bilateral nevus of Ito is an extremely rare condition. In exceptional cases nevus of Ito may be present simultaneously with the nevus of Ota.[17]

Here is a report containing a description about a very rare presentation of simultaneous presence of unilateral nevus of Ota, bilateral nevus of Ito and palatal lesions in a male person. A suggestion for the consideration regarding the restructuring of the Tanino's classification is also proposed herewith.

Case Report

A 24-year-old Indian male patient born out of non-consanguineous marriage, presented with bluish gray asymptomatic mottled pigmented patch on his right side of the face along with bluish discoloration of the upper part of the right eye since his infancy. He also complained of a similar pigmented lesion affecting both of his shoulder regions from his early days of life, though the lesion on the right shoulder started earlier. The discoloration became more prominent with the onset of puberty. He also reported that the intensity of the discoloration of all the lesions aggravates during the summer months. He does not have any complain about his problem except his concern for the cosmetic appearance. On enquiry he told that none of his family members have any such lesion. He did not give history of any major illness including any ophthalmological or auditory complaint.

On examination the lesion on the face was found to be distributed on the right side extending from temple to malar and mandibular regions [Figure 1]. Sclera of the ipsilateral side was also involved. He too had a large gray-bluish speckled pigmented lesion on his right and left shoulder regions [Figures 2 and 3]. The lesion on the right side was bigger in size and the deltoid and scapular areas were more affected than the supraclavicular region [Figure 4]. Few bluish pigmented patches were also found in the right side of the hard palate [Figure 5].

Figure 1

Nevus of Ota on the right side of the face with nevus of Ito on the right shoulder and deltoid region

Figure 2

Nevus of Ota with scleral lesion. Bilateral nevus of Ito is also seen on the shoulders

Figure 3

Nevus of Ito on the left shoulder

Figure 4

The extent of nevus of Ito was much bigger on the right shoulder

Figure 5

Right side of the hard palate showing multiple gray blue patches

Routine examinations of the blood, X-ray of the chest and CT scan of the brain revealed no abnormality. Ophthalmologic and ENT examines were normal. Histopathlogic examinations of the skin from the affected area of the face and shoulders showed the presence of heavily pigmented, elongated, dendritic dermal melanocytes. The overlying epidermis was normal.

Discussion

Both nevus of Ota and nevus of Ito are dermal melanocytoses. Though rare in white population, nevus of Ota affects near about 0.014-0.034% of the Asian population.[18] Nevus of Ota is usually unilateral in 90% of cases though at times bilateral cases may occur. Another important dermal melanosis, the nevus of Ito involves the area supplied by posterior supraclavicular and lateral cutaneous brachial nerves.

As about the pathogenesis of both the nevi, the failure of the melanocytes from the neural crest to migrate to the epidermis is held responsible. The bluish discoloration of the lesion is the result of Tyndall effect of the dermal melanocytes.[1920]

Nevus of Ota and nevus of Ito are found usually as solitary conditions but seldom may occur together. In a review it has been opined that half of the cases of nevus of Ito are associated with nevus of Ota. In comparison to nevus of Ota, nevus of Ito is much rarer and a bilateral distribution of the lesion is very rarely reported in English literature. In an article containing a series of 16 patients none had any bilateral lesion.[21] The association of bilateral nevus of Ito with the nevus of Ota is exceedingly rare phenomenon and we have come across three reports containing four cases of bilateral nevus of Ito so far in English literature [Table 1].[222324] In all these reported cases prevalence of nevus of Ito was more in females, the ratio of male: Female being 3:1 and extra cutaneous associations were present in two reports.

Table 1

Profile of cases with bilateral nevus of Ito

Nevus of Ota and nevus of Ito may be accompanied by extra cutaneous lesions.[51021] In case of nevus of Ota the palatal lesion is infrequent and occurs most frequently with bilateral nevus of Ota.[625] Till date only 12 (excluding the present case) have been reported in English literature.[26] This present case is interesting because of the association of nevus of Ota with bilateral nevus of Ito with palatal lesion. This combination so far has not been reported in the literature.

As far as the classification of the nevus of Ota is concerned, there are a number of classification exists but the Tanino's classification has remained the most popular one and widely used.[121314]

So far there is no classification system described for the nevus of Ito.

Though incidence of simultaneous presence of nevus of Ota and nevus of Ito is much less common in comparison to the solitary cases but with the publication of reports from different corners of the globe it may be suggested that the association of both the nevi in a single subject is a rare but not an impossible phenomenon. Rather, these two conditions may be interpreted as the different manifestations of a similar event Also, as far as the pathology of both the conditions are concerned the underlying features are identical in both nevi showing pigmented, spindle shaped dendritic melanocytes in upper and mid dermis.[2027] So, if we consider both the conditions from these points of view, instead of treating the conditions separately, a modification that would incorporate nevus of Ito as well as simultaneous presence of nevus of Ota and Ito in the existing Tanino's classification may be appropriate. Hence the new additional groups (along with the existing four groups) in the suggested modified clinical classification depending on the clinical features may be as follows:

Type V

VA: Unilateral nevus of Ito without nevus of Ota.

VB: Bilateral nevus of Ito without nevus of Ota.

Type VI

VIA: Unilateral nevus of Ota with unilateral nevus of Ito (ipsilateral and contralateral)

VIB: Bilateral nevus of Ota with unilateral nevus of Ito (ipsilateral and contralateral)

VIC: Unilateral nevus of Ota (ipsilateral and contralateral) with bilateral nevus of Ito

As the nevi may be associated with extra cutaneous manifestations a letter “E” may be suffixed with the class (e.g., type VIC-E etc.) wherever it is applicable.

This proposed classification will put both nevi in a common platform as the underlying pathogenesis and pathology is same though the area of distribution is different. This will help to avoid a separate classification for the nevus of Ito. The addition of the letter “E” for extra cutaneous associated features will also give a complete idea regarding the disease and its magnitude of affection. Also the physician will be more vigilant while dealing with either of the nevi as far as the prognosis and management strategy is concerned as malignant transformation may rarely occur in both the nevi.[28]

What is new?

1. Like nevus of Ota, nevus of Ito may also be bilateral, though very rarely.

2. Nevus of Ota may also exist with bilateral nevus of Ito along with extra cutaneous lesion.

3. Nevus of Ota and nevus of Ito may be put under a singular classification system which also keeps room for the extra cutaneous lesions.