Spitzoid melanoma in childhood

Spitzoid melanoma is a rare variant of melanoma. It has morphological features similar to those of Spitz's nevus. In this study, the histologic and immunohistochemical features of both Spitzoid melanoma and Spitz's nevus are emphasized. We report two cases of melanoma with spitzoid features occurring in the extremities of 9 and 8-year-old girls. Histologically both lesions had typical features of Spitzoid melanoma. We conclude that the differential diagnosis of Spitzoid melanoma and Spitz's nevus is at times problematic in childhood, in that distant metastasis may be the only diagnostic criteria for some cases to be distinguished from Spitz's nevus if strict criteria are followed. Spitzoid melanoma must be treated as other types of melanoma.     

Spitzoid melanoma: dermoscopic report and diagnostic discussion

We present a case of a 16-year-old young man who came for a dermatologic appointment due to acne. He presented a pigmented asymptomatic lesion on the back of his right thigh. Dermoscopic examination revealed uncommon aspects, highly suspect of nodular melanoma, in particular a blue-whitish veil, striae and asymmetric globules. The lesion was promptly removed and the material referred for histopathologic examination. Microscopic findings showed an atypical spitzoid tumor, compatible with spitzoid melanoma. In this report, the importance of dermoscopy as an auxiliary method in the early diagnosis of cutaneous melanomas is emphasized. Its daily use by the dermatologist is an important tool in the decision-making process in cases of urgent removal of suspect lesions.     

Spitzoid melanoma and micrometastases in two lymph node regions: a critical situation

Atypical Spitz tumors can hardly be differentiated from spitzoid melanoma. CGH might help in the differential diagnosis. An 8 year old child with an atypical Spitz tumor (with a CGH pattern compatible with melanoma) of 8.0?mm Breslow thickness and micrometastases in two lymph node regions was seen at our department. The management and prognosis of atypical Spitz tumors is controversial, and aggressive procedural steps similar to melanoma are usually not recommended. Even performing sentinel lymph node biopsy has been questioned. After extensive interdisciplinary consultations, we did not recommend resection of both lymph node regions and chose instead to follow-up with regular whole-body MRI and adjuvant treatment with pegylated interferon. Treatment decisions for atypical Spitz tumors are a major medical and ethical challenge due to the limited available data.     

Spitzoid and non‐spitzoid melanoma in children. A prognostic comparative study

Background Spitzoid melanoma is a rare melanoma subtype often developing in children with unknown biological potential. Objectives To compare the clinical and histopathological factors that influence the biological behaviour between spitzoid and non‐spitzoid childhood melanoma, to establish if the spitzoid subset of melanoma has different prognosis than other types of childhood melanomas. Methods A comparison of the prognostic significance of clinical and pathological findings between 38 spitzoid (SM) and 99 non‐spitzoid melanomas (N‐SM) in children and teenagers younger than 18 years referred to UT – MD Anderson Cancer Center during the period 1992–2007. Results Children with SM were significantly younger than those with N‐SM, had more frequently multiple melanocytic nevi, nodular melanoma subtype with vertical growth phase, high Breslow thickness and mitotic rate, positive sentinel lymph node biopsy and more advanced stage. N‐SM had more often associated nevus. However, the mortality rate in the SM group was lower (5.9%) than in the N‐SM group (12.0%). This study has two major limitations. Small size of both groups does not allow reaching statistically significant differences regarding mortality. Using metastatic potential as an inclusion criterion for SM could result in a sample selection bias of the most aggressive group of SM. Conclusions Although SM patients had poorer prognostic factors than N‐SM patients, slightly lower mortality rate was detected in the SM group. This less aggressive behaviour could be due to lower potential for widespread distant metastases than conventional melanomas or younger age of children with SM.     

Spitz样肿瘤研究进展

Spitz痣、非典型Spitz肿瘤和Spitz样黑素瘤的临床及组织学特征有重叠, 三者鉴别极具挑战。该文结合Spitz样肿瘤的临床和组织学特征, 综述其免疫组化特点和荧光原位杂交检测方法在本组疾病中的研究进展。     

Spitzoid melanoma in children: clinicopathological study and application of immunohistochemistry as an adjunct diagnostic tool

Introduction:  The term spitzoid melanoma (SM) is reserved for a rare group of tumors with striking resemblance to Spitz nevus, often developing in children diagnosed in retrospect after the development of metastases.
Objectives:  To determine the biological significance of SM and to analyze the effectiveness of adjuvant diagnostic techniques.
Materials and methods:  A retrospective, observational study of 38 cases of SM in patients younger than 18 years. Histological type, Clark level and Breslow thickness, radial and vertical growth phase, mitotic count/mm², ulceration, regression, vascular and perineural invasion, satellitosis, cytology and associated nevi were reviewed. An immunohistochemical analysis with HMB45 and Ki67 was performed in 10 cases. These features were correlated to patient's stage and outcome.
Results:  Analysis of histological and immunohistochemical features should allow accurate diagnosis in most cases. Given the low mortality rate, no conclusions about the prognostic significance of histological parameters of the primary tumor could be established.
Conclusion:  We report the largest series of SM from a unique center. Although these patients may have a better prognosis than adults, some patients with SM develop metastasis and die, particularly after age 11 years. Therefore, we recommend using the same treatments as in adults.     

Differential diagnosis of Spitzoid melanocytic neoplasms

Atypical Spitzoid neoplasms represent a controversial and incompletely defined diagnostic category for lesions with intermediate architecture and cytomorphology between Spitz nevus and melanoma. The vast majority of these neoplasms have a good overall prognosis. Only a small proportion of patients will end up developing distant metastases and death. The distinction between Spitz tumours with atypical features and Spitzoid melanoma remains difficult on clinical and histological grounds and the prediction of the biological behaviour of those tumours even with sentinel lymph node biopsy is impossible. Tools such as immunohistochemistry, genetic analysis, mutation analysis and mass spectometry have contributed to the better understanding of those tumours and may be useful in the differential diagnosis of Spitzoid tumours.     

A Case of Spitzoid Melanoma

Spitzoid melanoma is a subtype of melanoma that, clinically and histologically, resembles a Spitz nevus. Clinically, spitzoid melanomas usually evolve from amelanotic nodular lesions, growing to 1 cm or more in diameter. They often remain clinically undiagnosed because of their wide variety of clinical appearances and a lack of pigmentation. Distinguishing a Spitz nevus from a spitzoid melanoma can be extremely difficult. Features that favor the diagnosis of a spitzoid melanoma are asymmetrical shape, diameter greater than 1 cm, a lesion with a deep invasive component, and a high degree of cytologic atypia. There have been only rare reports in the literature of the presence of giant cells in malignant melanoma, and the presence of these cells may result in its misdiagnosis as a histiocytic tumor. We present a case of spitzoid melanoma on the right ankle of a 22-year-old-woman.     

Spitzoid melanoma with histopathological features of ALK gene rearrangement exhibiting ALK copy number gain: a novel mechanism of ALK activation in spitzoid neoplasia

Spitzoid neoplasms pose diagnostic difficulties because their morphology is not consistently predictive of their biological potential. Recent advances in the molecular characterization of these tumours provides a framework by which they can now begin to be categorized. In particular, spitzoid lesions with ALK rearrangement have been specifically associated with a characteristic plexiform growth pattern of intersecting fascicles of amelanotic spindled melanocytes. We report the case of an 87-year-old man with a 3-cm nodule on his mid-upper back comprised of an intradermal proliferation of fusiform amelanotic melanocytes arranged in intersecting fascicles with occasional peritumoral clefts. Immunohistochemical studies demonstrated diffuse, strong expression of SOX10 and S100 by the tumour cells and diffuse, weak-to-moderate cytoplasmic positivity for anaplastic lymphoma kinase (ALK), suggestive of ALK rearrangement. Fluorescence in situ hybridization revealed no ALK rearrangements but instead revealed at least three intact ALK signals in 36% of the tumour cells, confirming ALK copy number gain. To our knowledge, this is the first reported case of a plexiform spitzoid neoplasm exhibiting ALK copy number gain instead of ALK rearrangement. This case suggests that ALK copy number gain is a novel mechanism of ALK activation but with the same characteristic histopathological growth pattern seen among ALK-rearranged spitzoid neoplasms.     

Amelanotic Spitzoid Melanoma in the Burn Scar of a Child

Abstract: We report a 3-year-old girl with a rapidly growing, amelanotic, nodular melanoma developing within a burn scar over the dorsal aspect of the left foot. Histologically, the lesion was spindle cell and exhibited lack of maturation, cellular atypia, and scattered mitotic figures. Twenty five percent of the tumor cells were positive for proliferating cell nuclear antigen by immunohistochemical stain. A left inguinal lymph node was also positive for regional metastasis. The child died with disseminated metastases 13 months after the lesion was removed.     

Spitz样肿瘤320例临床及组织病理分析

【摘要】 目的 总结Spitz样肿瘤的临床及组织病理特征。方法 回顾2005年1月至2020年1月西京皮肤医院确诊的320例Spitz样肿瘤患者的临床及病理资料。结果 320例患者中,男141例,女179例,年龄0 ~ 65（12.5 ± 11.7）岁,病程1个月至30年;其中,Spitz痣307例,不典型Spitz肿瘤（AST）8例,Spitz痣样黑素瘤（SM）5例。皮损多为单发,可见于头面部、躯干和四肢,边界均清楚。307例Spitz痣皮损以黑色（132例,43.0%）和红色（108例,35.1%）为主,多数色素均匀（262例,85.3%）且表面平滑（272例,88.6%）。Spitz痣存在特殊临床亚型,11例 （3.6%）发生在斑痣上,11例 （3.6%）呈簇发性,6例（2.0%）播散性,7例（2.3%）结节性,1例（0.3%）为瘢痕疙瘩样。Spitz痣特征性病理表现包括表皮内痣细胞呈Paget样扩散（123例,40.1%）,真表皮交界处出现Kamino小体（74例,24.1%）,痣细胞呈水平带状（177例,57.8%）及楔形分布（118例,38.4%）,痣细胞巢周围出现裂隙（177例,57.8%）,可见生理性核分裂象（117例,38.1%）,核染色质均细腻。根据特殊组织病理表现,Spitz痣又分为色素性上皮样Spitz痣（9例,2.9%）、结缔组织增生性Spitz痣（13例,4.2%）、血管瘤样Spitz痣（8例,2.6%）、疣状Spitz痣（12例,3.9%）、黏液样Spitz痣（10例,3.3%）、晕痣样Spitz痣（4例,1.3%） 等。4例AST皮损为黑色,7例色素均匀,3例皮损表面粗糙;特征病理表现包括细胞均有轻度至中度的异型性,均可见核分裂象（7例为2 ~ 6个/mm2）,5例核染色质粗糙。3例SM皮损呈红色,4例色素不均匀,3例表面粗糙;特征病理表现包括黑素细胞呈Paget样扩散（3例）,瘤细胞呈无极性浸润性生长且均未见成熟现象,均有明显异型性,并可见病理性核分裂象（3例, > 6个/mm2）,核染色质均粗糙且核膜明显着色。结论 Spitz样肿瘤的临床及组织病理表现具有特征性,Spitz痣的临床及病理亚型繁多,AST同时具有Spitz痣和黑素瘤的临床及组织学特征。     

Spitz nevi and other Spitzoid lesions part I. Background and diagnoses

Spitz nevi are melanocytic proliferations that are characterized by spindled and/or epithelioid nevomelanocytes. First interpreted as juvenile melanoma, these lesions were later characterized as benign and were observed to affect all age groups. Today, contrasting opinions persist regarding the fundamental benignancy versus malignancy within the spectrum of Spitz tumors. Beyond clinical outcome, this controversy has also been fueled by complex and sometimes convoluted classification schemes based on pathologic characteristics. More recently, immunophenotypic and molecular analyses have begun to clarify the etiologic nature of these tumors. Recent evidence suggests that histopathologic features that suggest more aggressiveness in Spitz tumors relate to mitoses and inflammation.