Multiple agminate Spitz naevi: review of the literature and report of a case with distinctive immunohistological features

The Spectrum of Spitz Melanocytic Lesions: From Morphologic Diagnosis to Molecular Classification

Spitz tumors represent a distinct subtype of melanocytic lesions with characteristic histopathologic features, some of which are overlapping with melanoma. More common in the pediatric and younger population, they can be clinically suspected by recognizing specific patterns on dermatoscopic examination, and several subtypes have been described. We now classify these lesions into benign Spitz nevi, intermediate lesions identified as “atypical Spitz tumors” (or Spitz melanocytoma) and malignant Spitz melanoma. More recently a large body of work has uncovered the molecular underpinning of Spitz tumors, including mutations in the HRAS gene and several gene fusions involving several protein kinases. Here we present an overarching view of our current knowledge and understanding of Spitz tumors, detailing clinical, histopathological and molecular features characteristic of these lesions.

Agminate lichen aureus

Lichen aureus is a rare variant of pigmented purpura, with a chronic and benign course. It is generally asymptomatic and often occurs in the lower limbs, presenting as erythematous brownish, coppery or golden macules and/or papules. The diagnosis is based on clinical and histopathological findings. The dermatoscopic pattern has been considered a useful tool in diagnosis presumption. We describe a case with a confluent morphological pattern, called agminate lichen aureus.

Linear arrangement of hypopigmented Spitz nevi on the ear after trauma

A 10-year-old boy had multiple papules after surgery on a primary lesion on his left ear. The papules were pink and showed a linear arrangement around the helix. Histopathological examination of two separate lesions showed proliferation of epithelioid cells in the dermis and some of them formed nests. No melanin was found in the epithelioid cells, and immunohistochemistry staining with S100, HMB45 and Melan-A were positive in the neoplasm cells. According to the clinical and histopathological characteristics, it was diagnosed as hypopigmented Spitz nevi with linear arrangement after trauma.

Cervical metastasis from Spitz nevus of the buccal mucosa

A 23-year-old woman was presented with a prolonged history of a small lump in the buccal mucosa. A local excision was performed. The morphology diagnosed a Spitz nevus and she underwent supplementary excision of scar tissue. Two years later a submandibular lump appeared on the ipsilateral side of the neck. Cytology from fine needle aspiration indicated spread of a melanocytic tumor and she underwent a modified supraomohyiod neck dissection. One of the lymph nodes showed an inclusion of cells in the deep layers with epitheloid and spindle cells in a pattern similar to that of the primary oral lesion. The finding suggests a mechanical spread of melanocytes from the Spitz nevus to the regional lymph node. After more than 3 years of follow-up there is no further manifestation of disease. It is believed that this may be an example of how a Spitz tumor, although inherently benign, can spread along lymphatics in a pseudometastatic fashion. To our knowledge this is the first report of an oral Spitz melanoma with metastatic behavior.

Multiple Spitz naevi: a report of both variants with clinical and histopathological correlation

Spitz naevi are usually solitary lesions. Multiple Spitz naevi are extremely rare and reported as widespread (disseminated) or grouped (agminated). We report two cases of multiple Spitz naevi and review their aetiology and treatment.

Agminated Spitz nevi: report of a child with a unique dermatomal distribution

Spitz nevi most commonly present as solitary lesions. Multiple agminated Spitz nevi are a rare presentation, with 38 reported cases in the English language literature. We report a 2-year-old girl who presented with multiple Spitz nevi in a unique, dermatome-like distribution and review the English-language literature on agminated Spitz nevi.

Agminated acquired melanocytic nevi of the common and dysplastic type

We previously reported a single case of agminated acquired melanocytic nevi, consisting of a localized clustering of banal and atypical moles. We now report 4 more cases, confirming that the initial case was not an isolated finding. We examined the lesions clinically, with a dermoscope, with a Wood's light, and in 3 cases with UV photography so as to exclude nevus spilus from the differential diagnosis. The presence of an underlying dysplastic nevus syndrome phenotype in 4 of the 5 cases raises the possibility that agminated nevi arise as a consequence of postzygotic loss of heterozygosity and, thus, may represent a type 2 segmental manifestation of the atypical mole syndrome phenotype. Further studies of similar cases using microdissection techniques for analysis of loss of heterozygosity pattern are warranted.

Proliférations mélanocytaires de l’enfant

Melanocytic nevi in children can be acquired or congenital. The vast majority are benign but diagnosis can be difficult. Nevi in newborns and nodular proliferations in giant congenital nevi can display histological features that lend to their misdiagnosis as melanoma. Acquired melanocytic nevi in children are often Spitz nevi or related nevi. These lesions are too often misdiagnosed as melanoma. On the other hand, clinicians and pathologists must be aware that melanoma does occur in childhood, albeit very rarely. It is exceptionally rare in prepubescent individuals. It can be associated with the following risk factors: giant congenital nevus, family history of melanoma, xeroderma pigmentosum, and immunosuppression. Melanoma in children younger than 10 years of age is extremely rare and has different clinical and histopathological features than those that arise in postpubescents, often being confused with a Spitz's nevus. Consequently, the diagnosis is often made too late. It should be emphasized that thickness is the main prognostic parameter in childhood melanoma and that early diagnosis is also crucial in this age group. The lesion must therefore be examined in a complete excision and not in a partial biopsy, and if atypical features are present it must be reviewed by an expert. On the other hand extreme caution should be exercised when diagnosing melanoma in children, as some benign lesions exhibit similar histologic features.

Agminated histiocytomas in a 23-year-old patient

A 23-year-old patient presented with a group of 17 reddish-brown papules and nodules on the left shoulder lasting for 4 years. The histopathologic examination after a punch biopsy was repetitively consistent with the diagnosis of fibrous histiocytoma (FH). We use the term agminate histiocytomas for the first time to stress the presence of grouped lesions in one skin segment. Intralesional corticosteroids and cryotherapy were partially successful in this patient.

Spitz nevus and its histologic simulators

Spitz nevi continue to pose a considerable diagnostic challenge to the histopathologist. Key features of Spitz nevus and its variants are discussed and contrasted with the telltale signs of malignancy of "Spitzoid" melanomas. The importance of the histologic features of the deep, rather than superficial, part of the lesions is emphasized.

Multiple agminated Spitz nevi arising on a café au lait macule: review of the literature with contribution of another case

The majority of Spitz nevi are acquired solitary lesions. Multiple Spitz nevi are rare and may develop on hyperpigmented skin. We report a 16-year-old girl with multiple Spitz nevi arranged on a café au lait macule. Immunohistochemistry showed positivity for S-100 and HMB-45. Of interest, expression of Polo-like kinase (PLK), a novel proliferation marker that recently proved to be positive in up to 98% of malignant melanoma cells, showed positivity in 40% of the nevus cells. The clinical development of multiple Spitz nevi is not yet clear, as they are preferentially excised. Reviewing 70 cases in the literature we found that multiple agminated Spitz nevi occur more frequently than reported previously. In about one-third of these cases Spitz nevi arose on congenitally hyperpigmented skin.

Multiple widespread eruptive Spitz naevi

A 19-year-old man presented with a widespread eruption of several hundred Sptiz naevi. He is still developing new lesions, 4 years after the problem began. No treatment to date has been satisfactory. The literature on prognosis and treatment of this condition is reviewed.

Agminate Spitz naevi occurring in an adult after the excision of a solitary Spitz naevus--report of a case and review of the literature

We describe a 21-year-old female who presented with four agminate Spitz naevi close to the scar from a previously excised solitary Spitz naevus, and review the literature since 1987 on widespread and agminate Spitz naevi. Spitz naevi usually present as solitary firm red or brown papular lesions. Agminate Spitz naevi are unusual and they have been reported mainly in children. It is uncommon for Spitz naevi to recur after surgery and far more unusual for a recurrence to occur in an agminate form. Such lesions may mimic multiple satellite and in-transit metastases which can occur in malignant melanoma, and close follow up of any new lesions occurring in this case is intended.

Giant recurrence of a multiple agminated Spitz nevus

An 11-year-old boy had multiple agminated pigmented lesions distributed over the left scapula since the age of 2 years. Shave excision of four grouped lesions showed Spitz nevi (benign juvenile melanoma, spindle or epithelioid cell nevi) that were not totally excised basally. Three years later, a tumorous, keloidlike nodule developed on that site. To the best of our knowledge, giant recurrence within an agminated Spitz nevus has not previously been reported.

Multiple agminated Spitz nevi: report of two cases and review of the literature

Spitz nevus is most commonly a benign solitary lesion. Multiple lesions arranged in clusters (agminated) are very rare. Malignant degeneration has not been reported. Although spontaneous involution may occur, the nevi are frequently treated by surgical excision. We describe two preschool girls with multiple agminated Spitz nevi, and review the current world literature on multiple Spitz nevi.

Agminate Spitz naevi arising on hyperpigmented patches

In 1948 Dr Sophie Spitz described criteria that distinguished juvenile melanoma from malignant melanoma. Since then the cases of eruptive Spitz naevi have been reported arising on normal skin, on lightly pigmented patches and on hypopigmented patches. There are only 12 reports of Spitz naevi arising on hyperpigmented patches: we describe here three further cases, all on the arms of children, seen in our department in a single year.

Speckled compound naevus

We report a case of a localized speckled compound naevus arising within normally pigmented skin. Speckled melanocytic naevi are reviewed and the distinctive features of the case enumerated.

Multiple agminate Spitz nevi

A five-year-old boy had multiple agminate Spitz nevi arising in an area of hyperpigmentation that developed concurrently with the nevi. Multiple Spitz nevi occurring in a single group are rare, and their presence on a hyperpigmented background is extremely uncommon. Very few such cases have been described, and all of those lesions arose on a congenital hyperpigmented patch. In contrast, the nevi in our patient appeared to arise on an acquired hyperpigmented patch that was not present at birth, and histologically did not demonstrate features of a congenital nevus. Accurate diagnosis is necessary to avoid unnecessary radical therapy.

Immunohistologic evidence for the malignant potential of congenital melanocytic nevi

Monoclonal antibodies (MoAbs) against six well-defined progression-associated melanoma antigens (PAMAs) and a MoAb against the nuclear proliferation-associated antigen Ki67 were used for an immunoperoxidase study on 44 biopsies from 36 congenital melanocytic nevi (CMN). Twenty-nine common acquired nevi and 16 metastasizing primary melanomas were studied as controls. Two CMN of the series were giant CMN (greater than 20 cm), one of which later progressed to metastasizing melanoma. Of the remaining 34 CMN, four were histologically associated with a malignant melanoma. DNA flow cytometry was performed on adjacent cryostat sections of 37 biopsies from 28 CMN without melanoma. PAMAs were found expressed in CMN in the following frequencies: A-1-43: 36%; P358: 27%; PAL-M1: 20%; HLA-DR: 9%; Muc 18: 2%; A-10-33: 0%. No PAMAs were present in only 15 biopsies (34%). One single PAMA was found in 20 lesions (45%), and two or more PAMAs in nine lesions (21%). In all four CMN histologically associated with melanoma, and also in one biopsy from the giant CMN which later progressed to melanoma, at least two PAMAs were expressed. The latter biopsy was the only CMN in which the proliferation-associated antigen could be demonstrated. Only this biopsy and a single biopsy of the other giant CMN showed aneuploidy. We found expression of single PAMAs and co-expression of PAMAs in CMN in higher frequency than in common acquired melanocytic nevi. Co-expression of PAMAs was a feature of metastasizing primary melanomas. We conclude that co-expression of two or more PAMAs in a CMN might indicate its malignant potential, because this was found in all CMN proven to have progressed to malignant melanoma.