Archive for the ‘Disease’ Category

Halo nevus rarely occurs in a congenital nevus. The mechanisms leading to the development of halo nevus are still a matter of debate, but the main hypothesis involves a cellular immune response targeting the pigmented cells, and this is perhaps elicited in some cases by the presence of abnormal, probably premalignant melanocytes either within or at some distance from the halo nevus. Some researchers have postulated that the halo nevus is related to the atypical nuclear changes “commonly” found in the scattered, dark brown speckles in the brown patch of nevus spilus. These atypical nuclear changes act as the initiating factor for an immune response. Once the immune response is initiated, it recognizes common antigens in both the atypical cells and the normal cells. It is the immunologic response that causes the halo phenomenon to cross- react with normal nevus; this would explain the occurrence of multiple halo nevi in some patients.


A 13-year-old boy presented with a 3×4 cm, well demarcated, pale brown colored patch with multiple scattered, dark brown colored speckles, which were 2~3 mm in diameter, on the right side of neck, and these lesions were present since birth. At the age of 6, a white hypopigmented zone had developed around the nevus and it had gradually enlarged to 7 mm in diameter (Fig. 1A). In addition, vitiligo lesions were found in the periorbital, perinasal and perioral regions, simultaneously with the halo nevus (Fig. 1B). There was no personal or family history of autoimmune disorders. The histopathological findings of the hypopigmented lesion revealed a finding of decreased melanin in the basal layer of the epidermis, and the pale brown colored patch lesion revealed elongation of the rete ridges and increased melanin pigmentation in the basal layer of the epidermis (Fig. 2A). (more…)

Development of Halo Nevus Around Nevus Spilus as a Central Nevus

Feb 23, 2011 Author: Walter Mcneil | Filed under: Disease

Halo nevus


Halo nevus has been termed as leukoderma acquisitum centrifugum or Sutton’s nevus; this is a benign melanocytic nevus that’s surrounded by a hypopigmented zone, and this type of lesion is found in about 1% of the normal population. Depig­mented zones appear mostly around several types of acquired pigmented lesions, such as dermal, junc- tional and compound nevi, Spitz’s nevus and malignant melanomas. In contrast, it is rare that depigmented zones develop around a congenital nevus. Sometimes, vitiligo also appears concurrently in the nearby regions, as in our current case. Vitiligo is frequently associated with a halo nevus (18 ~ 26%), and appears in nearby regions as well as at other remote sites. (more…)

A Case of Intradermal Melanocytic Nevus: DISCUSSION

Feb 22, 2011 Author: Walter Mcneil | Filed under: Disease

Bone formation within the skin may be a primary or secondary phenomenon. Primary cutaneous ossi­fication can occur in Albright’s hereditary osteo­dystrophy and as primary osteoma cutis. Secondary metaplastic ossification occurs in association with a wide variety of conditions, including pilomatricoma, basal cell carcinoma, acne, melanocytic nevi, cel­lular blue nevus, scar, cutaneous mixed tumor, cylindroma, a cutaneous nodule of mixed connective tissue disease, dermatofibroma, ossifying plexiform tumor, pyogenic granuloma, cutis laxa-like pseudo- xanthoma elasticum, congenital plate-like osteoma cutis, organoid nevi, epidermal cyst and at the site of trauma or injection. The melanocytic nevus with secondary ossification is referred to as ‘nevus of Nanta. Melanocytic nevus with bone was first described by Heidingsfeld in 1908. Ever since Nanta reported on it in detail in 1911, it has been called osteo-nevus of Nanta. The histopathology of nevus of Nanta is characterized as ossification within or just beneath the nevus cell nests.


A Case of Intradermal Melanocytic Nevus: CASE REPORT

Feb 21, 2011 Author: Walter Mcneil | Filed under: Disease

A 49-year-old woman presented with a 30-year history of asymptomatic plaque on her right temple. Dermatological examination revealed a 1.5 cm in diameter, erythematous to flesh colored, flat topped plaque with hairs (Fig. 1). She had no history of drug intake or medical illness. The histological examination showed a dense proliferation of benign nevus cells in the upper dermis. They were arranged in nests surrounding the hair follicles (Fig. 2). (more…)

A Case of Intradermal Melanocytic Nevus

Feb 20, 2011 Author: Walter Mcneil | Filed under: Disease

Melanocytic nevus


Ossification within the skin may occur in a variety of conditions, including pilomatricoma, basal cell carcinoma, appendageal and fibrous prolifera­tion, inflammation and trauma. The occurrence of ossification within a melanocytic nevus is an un­usual event.


Mastocytosis is characterized by the abnormal growth and accumulation of neoplastic mast cells in one or more organs. The skin is the most common site for the abnormal accumulation of mast cells, known as cutaneous mastocytosis. Clinical cate­gories of cutaneous mastocytosis, in order of fre­quency of occurrence, include urticaria pigmentosa, mastocytoma, diffuse cutaneous mastocytosis, and telangiectasia macularis eruptiva perstans (TMEP). It has been reported that mastocytoma had de­veloped in a patient in association with another form of cutaneous mastocytosis. Okun and Bhawan reported a combined melanocytoma-mastocytoma in a patient of nodular mastocytosis, and Wood et al. reported a case of fibrous mastocytoma in a patient with generalized cutaneous mastocytosis. Our pa­tient had had urticaria pigmentosa since childhood and two years prior to examination, combined mastocytoma-hemangioma had developed as another histopathologic features from those previously re­ported.


A 53-year-old woman was presented to our clinic to evaluate an asymptomatic skin lesion on the right ear that had developed two years before. Her past medical history was contributory to uticaria pig- mentosa since childhood which had been treated by PUVA (Fig. 1). Bone marrow biopsy, which was performed before the skin lesion developed, re­vealed hypercellularity (90%) and hyperplasia (50%) of mast cells. Mast cells in bone marrow were positive for specific esterase, c-kit (CD117). Com­plete blood count and blood chemistry studies were normal ranged except for a slight thrombocytopenia. There was no family history for skin cancer or mastocytosis. On the physical examination, there was a 0.5×0.7 cm reddish to purplish soft papule on the posterior part of right ear (Fig. 2). But the Darier’s sign was unsuspicious. Excisional biopsy was performed, and the specimen was fixed in 10% formalin and routinely embedded into paraffin for H&E and Giemsa staining. (more…)



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