Pigmented spindle cell naevus and its variants: distinction from melanoma

We report seven examples of pigmented spindle cell naevus (PSCN) and variants, emphasizing their histopathologic differentiation from malignant melanoma (CMM). Confusion with CMM may occur because of upward migration (pagetoid spread) of cells, prominent lateral extension of lentiginous melanocytic hyperplasia, and cytological atypia in spindle cell naevi. However, these proliferations are usually associated with a symmetrical and orderly growth pattern, confinement of the pagetoid spread to the lower epidermis, 'maturation' of the dermal component, and lack of marked cytological atypia.     

Successful differentiation of Spitz naevus from malignant melanoma by microfluorometric analysis of cellular DNA content

Two cases of presumed Spitz naevus, whose diagnosis on clinical and histological grounds was uncertain, were examined for cellular DNA content using the technique of DAPI-DNA microfluoromety. They were compared with 20 cases, respectively, of clinically and histologically confirmed, Spitz, naevus, malignant melanoma and acquired pigmented naevus. The two Spitz naevi showed a diploid pattern in a distribution histogram of cellular DNA content. The pattern was similar to that of confirmed Spitz naevi and of acquired pigmented naevi but different from the aneuploid pattern of malignant melanomas. DNA index values of the two cases were within the range of confirmed Spitz naevi and different from those of malignant melanomas. The DAPI-DNA microfluorometric method thus provided confirmatory evidence for the diagnosis of Spitz naevus. The method appears to reflect sensitively the biological behaviour of tumour cells, and is a useful aid to the diagnosis of uncertain Spitz naevi.     

Pigmented spindle cell naevus of Reed: a controversial diagnostic entity in Australia

Background/Objectives: The Reed naevus or pigmented spindle cell naevus of Reed (PSCN) was previously considered a pigmented variant of the spindle cell‐type of Spitz naevus. It is now considered a distinct entity and may overlap with cutaneous melanoma in both clinical and dermatoscopic features. We hypothesised that PSCN is an under‐recognised entity in Australia and present a typical case. To test our hypothesis, we performed a clinically based survey of Australian dermatology trainees (Registrars). A further aim of our study was to determine the approach of dermatology trainees in this country to the management of this type of lesion. Methods: A web‐based survey questionnaire based on the presented case was circulated to trainees of the Australasian College of Dermatologists. Responses, including level of training and initial approach to management, were collated and form the basis of the results presented herein. Results: Of 39 respondents, 13 (33%) diagnosed the lesion as PSCN. The majority (33/39; 84.6%) indicated they would biopsy the lesion, with most of these (91%) preferring excisional biopsy. Conclusions: The results support our hypothesis that PSCN is under‐recognised in Australia. The results also show that despite difficulty distinguishing this lesion, management of these lesions by dermatology trainees in Australia is consistent and parallels current recommendations.     

Treatment options for giant congenital naevi

Giant congenital naevi (GCN) are disfiguring, potentially malignant pigmented naevi present at birth. The naevus cells in GCN are found throughout the dermis and sometimes penetrate the subcutaneous septa. It is claimed that superficial, more heavily pigmented and biologically different naevus cells reside in the upper dermis. Partial removal of these superficial naevus cells by dermabrasion, laser therapy, curettage or shave excision is less traumatic than excision surgery and produces an acceptable cosmetic result. However, none of these techniques or excision of GCN to superficial fat completely removes the risk of malignant transformation.     

HMB 45 positive balloon cells in combined nevi]

The combined naevus is made up of two components, one resembling a melanocytic naevus, the other a blue naevus. Clinically, these naevi do not give any obvious cause for concern. Histological examination shows that the combined naevus consists of a superficial melanocytic naevus and a deep-seated spindle cell blue naevus. There is a rare variant in which the pigmented spindle cells of the "blue" naevus are replaced by large balloon cells varying in melanin content. These combined naevi, because of the large cells with abundant cytoplasm, closely resemble malignant melanoma. As a further aid to diagnosis we used the monoclonal antibody HMB 45. In our study, the vesicular cells in all seven combined naevi examined reacted strongly with HMB 45. It is suggested that HMB 45 is not always helpful in differentiating between melanoma and naevi.     

Cockarde naevus

Two cases with unusual pigmented naevi are reported. Only reports of two cases with similar naevi could be found in the literature. These multiple pigmented moles occur with uniform clinical morphology in young people. The target-like morphology is described and the histology which varies to some degree in these cases is fully described. However, the central lesion in all of them was a junctional naevus. The benign nature of these lesions and their distinction from Sutton Halo Naevi is emphasized.     

Immunological associations of the halo naevus with cutaneous malignant melanoma

Antibodies against the cytoplasm of malignant melanoma cells have been found formerly to be circulating in our patients with primary malignant melanoma before metastases had developed. We have found now this same antibody in fifteen patients with resolving halo naevi. It disappears once resolution of the naevus is complete or after a solitary active halo naevus has been excised. However, cytoplasmic antibody has not been detected in the serum of any other patients with cutaneous pigmentary disorders: including fifty-six with various pigmented tumours or naevi, many of them referred to us as suspected malignant melanoma; forty-seven with vitiligo unassociated with halo naevi; and six with benign juvenile melanoma. We postulate that:

• 1 Halo naevus represents an accelerated and successful rejection phase of a pigmented mole developing malignant change.
• 2 There are at least two aetiological types of vitiligo, the common variety and another one associated specifically with halo naevus, perhaps initiated by the same immunological stimulus or its sequelae.
• 3 Juvenile (benign) melanoma is not related immunologically to malignant melanoma.

     

GIANT PIGMENTED NAEVUS: THE FREQUENCY OF MALIGNANT CHANGE AND INDICATIONS FOR TREATMENT IN PREPUBERTAL CHILDREN

The chance of malignancy developing in a giant pigmented naevus is often regarded as sufficiently high to justify prophylactic removal of all giant pigmented naevi as soon as possible, but most of the reports from which these figures are derived appear biased because of selection of patients. Because malignant melanoma seemed extremely rare in the Australian prepubertal child, attempts were made to document its frequency. Despite difficulty in obtaining complete figures, sufficient information was obtained to confirm the extreme rarity of malignant melanoma in general and especially arising in a giant pigmented naevus before puberty. It is therefore suggested that there is no general indication for prophylactic removal of giant pigmented naevi in Australian prepubertal children. Indications for removal on cosmetic grounds are discussed. It is speculated whether these conclusions might apply in other countries.     

‘Congenital follicular melanocytic naevi’: a more appropriate term for spotted grouped pigmented naevi

We report two patients with an uncommon form of pigmented naevus consisting of grouped follicular papules. A biopsy taken from the lesions showed multiple naevus cells, predominantly around the hair follicles, with sparing of the eccrine glands. The clinicohistopathological term given for this condition is ‘spotted grouped pigmented naevi type I’, and has rarely been reported. We discuss the unusual morphology and differential diagnosis of this condition, and suggest that the term ‘congenital follicular melanocytic naevi’ is more appropriate for this presentation.     

Epithelioid blue naevus of the genital mucosa: report of four cases

Epithelioid blue naevi are an unusual cytological variant of blue naevus that have been recently described mostly in patients with the Carney complex, although they may also occur in isolation. This variant of blue naevus is composed of melanin-laden polygonal epithelioid melanocytes situated within the dermis. The neoplastic cells show no maturation with progressive depth of dermal infiltration and, in contrast with the usual stromal changes in blue naevi, epithelioid blue naevi exhibit no dermal fibrosis. We describe four cases of epithelioid blue naevus located on the genital mucosa in four patients with no evidence of the Carney complex. Three male patients showed an epithelioid blue naevus on the mucosa of the glans penis and a female patient had a lesion of the right labium minoris. Histopathologically, the lesions consisted of entirely intradermal melanocytic naevi composed mostly of heavily pigmented epithelioid melanocytes involving the dermis of the genital mucosa. Immunohistochemically, in all cases, epithelioid melanocytes expressed immunoreactivity for S-100 protein, HMB-45, Melan-A and MiTF antibodies.     

Spectrophotometric analysis of melanocytic naevi during pregnancy

Malignant melanoma is the most common cancer during pregnancy, but it is unknown whether melanocytic naevi in general are activated. A total of 381 melanocytic naevi in 34 Caucasian primigravidae were examined using spectrophotometric intracutaneous analysis (SIAscopy) technology in early pregnancy and prior to delivery. The Siagraphs of each naevus were then compared in order to evaluate changes over time. A total of 163 melanocytic naevi in 21 nulliparous women served as an additional control group. At the first visit none of the Siagraphs examined for the case or control groups aroused suspicion of dysplastic naevus or melanoma and no significant structural changes were noted during the observation period. However, 2.1% of the melanocytic naevi in the pregnant group increased and 1.3% decreased in size. Corresponding figures in the non-pregnant group were 1.8% and 0%, respectively. Only one naevus in a pregnant woman increased slightly in epidermal pigmentation, and a decrease in pigmentation was noted in 3.7% of the melanocytic naevi in the cases and 1.8% in the controls. None of the differences within or between the groups was statistically significant. We conclude that pregnancy does not influence the appearance of pigmented naevi. A changing naevus during pregnancy should be examined carefully and considered for excision and histopathology.     

Morphological features of Spitz naevus as observed by digital videomicroscopy

A characteristic epiluminescence pattern of pigmented epithelioid and/or spindle cell naevus, or Spitz naevus, has been described previously. The aim of this study was (i) to evaluate the characteristic morphological features both of pigmented and non-pigmented epithelioid and/or spindle cell naevi observed employing a videomicroscope, (ii) to identify their histopathological correlates and (iii) to assess the improvement in diagnostic accuracy for epithelioid and/or spindle cell naevi obtained by means of this new instrumental device. Clinical, videomicroscopic and histopathological diagnoses were performed on 26 epithelioid and/or spindle cell naevi. Moreover, the videomicroscopic pattern of each lesion was described using appropriate morphological parameters. Based on their morphological aspect detected by digital videomicroscopy, epithelioid and/or spindle cell naevi can be subdivided into three main groups: (i) darkly pigmented lesions, (ii) red or light brown ESC naevi, and (iii) lesions with dark or brown areas on a light-brown background. Whereas most epithelioid and/or spindle cell naevi of the spindle cell type belonged to the morphological group I and group 3, most epithelioid cell lesions appeared as red or light-brown coloured naevi. Finally, instrumental observation by means of a videomicroscope enabled an improvement in diagnostic accuracy with respect to the naked eye observation, with an increase in sensitivity from 15% to 58%.     

Multiple pigmented naevi in an albino

A case of pigmented naevi arising in an albino is described. The histological appearance of a naevus described and the nature of the pigment discussed.     

,,Blaue`` Variante eines Naevus spilus

Summary We report on a 29-year-old female patient with an unusual pigmented lesion of the face. Clinically the lesion looked like a pigment patch of the naevus spilus type, while histological examination revealed the presence of dermal melanocytosis and multiple common blue naevi with a discrete lentiginous component in addition. The melanocytic nature of the infiltrate was ascertained by immunohistochemistry analysis using S 100 protein and HMB 45 antibodies. We interpret this lesion as agminated blue naevi in association with lentigo simplex, an unusual variant of speckled lentiginous naevus.      

Do pigmented naevi in albinism provide evidence of tyrosinase positivity?

We investigated a 4-year-old Japanese boy with oculocutaneous albinism who had a solitary pigmented mole measuring 5 mm in diameter on his back. An electron microscopic tyrosine incubation test and a DOPA reaction test clearly demonstrated the presence of tyrosinase activity in the patient's hypopigmented skin. The presence of tyrosinase activity was confirmed by tests on hair bulb samples. Histopathological evidence showed that the mole was a typical compound cellular naevus with melanin pigmentation. Although no reports to date have focused on the relationship between pigmented naevi in albinism and tyrosinase activity, our findings suggest that the occurrence of pigmented naevi in an albino may indicate the presence of tyrosinase activity.     

Spitz naevus is rare in Korea

Background. Spitz naevi have not been widely studied in Asians. Aim. To compare the epidemiology and clinicopathological features of Spitz naevi in Koreans with lesions in western countries. Methods. In total, 80 Spitz naevi in 77 patients diagnosed over 10 years at 17 university hospitals in Korea were analysed. Results. The relative incidence of Spitz naevus vs. MM was 1 vs. 10.9. In most patients (75%) the Spitz naevi had been present for > 6 months. The size of the lesion was relatively large. Histologically, most of the lesions (54%) were the dermal type and pigmentation was common (49% of lesions). Immunohistochemical study found that all of the 34 lesions were positive for S‐100 protein but only 14 (47%) were positive for HMB‐45. Conclusion. Spitz naevus is rare in Korea. The lesions were more commonly larger, pigmented, and of the dermal type than reported in western countries.     

色痣和蓝痣的电镜观察

对4例色痣和2例蓝痣进行了电子显微镜观察.发现色痣的痣细胞中充满着许多第皿期和第N期黑素小体.蓝痣的黑素细胞在真皮深部.胞质中的黑素颗粒也相当多.在色痣和蓝痣的痣细胞中可见含黑素的大球形体.可能代表退行现象,也许是溶酶体吞噬了退变的黑素颗粒而形成的.最后讨论了色痣和蓝痣临床色泽差别的原因,蓝痣除黑素细胞部位深、受折光物理因素影响外.细胞中黑幸小体的含量、着色程度也有一定影响.     

Precocious puberty in a boy with a widespread linear epidermal naevus

A 7-year-old boy with a systematized verrucous epidermal naevus, multiple pigmented naevocytic naevi and precocious puberty is described. The possible basis for this previously unreported association of abnormalities is discussed.     

GENETIC CONSIDERATIONS IN GIANT PIGMENTED HAIRY NAEVUS

SUMMARY.— The pedigrees of 3 patients with giant pigmented hairy naevus (GPHN) were investigated. The occurrence of multiple small pigmented naevi in members of the patients' families is reported and it is suggested that at least some cases of GPHN may be determined by an autosomal dominant gene of variable expressivity.     

Pigmented terminal hair cysts within an intradermal melanocytic naevus

The combination of melanocytic naevi and cysts of adnexal or epithelial origin has been described previously. Herein we describe a case of intradermal melanocytic naevus containing pigmented terminal hair cysts, a rare variant of epithelial cysts. Our observation suggests that pigmented follicular cysts and combined cystic-melanocytic lesions may be attributed to follicular occlusion.