| Abstract|| |
Cutaneous melanoma in childhood is a rare disease. Rendering a clinical diagnosis of melanoma in pediatric patients is confounded by the fact that pigmented lesions in pediatric patients do not conform to the ABCDE rules applicable to adult patients. Furthermore, making a histologic diagnosis of cutaneous melanoma in childhood is also difficult with no universally accepted criteria applicable to pediatric melanomas. We report the case of a 5-year-old child presenting with intraparotid lymph node metastasis who was later found to have melanoma involving periorbital region. It is proposed that careful analysis of histologic features as well as the additional information provided by immunohistochemistry should allow for a correct diagnosis in most cases of melanoma in children.
Keywords: Cutaneous, malignancy, melanoma, pediatric
|How to cite this article:|
Kumar A, Deka L, Varshney B, Aiyer HM. Cutaneous melanoma in childhood presenting as intraparotid lymph node metastasis. Indian J Pathol Microbiol 2018;61:567-9
|How to cite this URL:|
Kumar A, Deka L, Varshney B, Aiyer HM. Cutaneous melanoma in childhood presenting as intraparotid lymph node metastasis. Indian J Pathol Microbiol [serial online] 2018 [cited 2019 Jan 23];61:567-9. Available from: http://www.ijpmonline.org/text.asp?2018/61/4/567/242976
| Introduction|| |
We present the case of a 5-year-old female child with cutaneous melanoma in the right periorbital region presenting with intraparotid lymph node metastasis. This case highlights the fact that pediatric pigmented lesions do not follow the ABCD criteria of adults and are thus liable to later detection, often at an advanced stage with lymph node metastasis.
| Case Report|| |
A 5-year-old female child presented with a complaint of swelling in the right retroauricular region for the past 2 months. Local examination revealed a firm, nontender swelling measuring 3 cm × 2.5 cm × 2 cm. Systemic examination and family history were noncontributory.
Fine needle aspiration cytology of the lesion was done and showed pleomorphic spindle-to-epithelioid cells with prominent nucleoli. A diagnosis of high-grade malignant tumor was given, and excision biopsy and histopathologic examination were advised.
Right parotidectomy and right cervical level II–V lymph node dissection were performed and the specimen was sent for histopathologic examination. A large intraparotid lymph node was noted with metastatic deposit of high-grade malignant tumor with spindle and epithelioid cytomorphology and prominent nucleoli [Figure 1]a. On immunohistochemistry (IHC), the malignant cells showed immunopositivity for S-100, melan-A [Figure 1]b, HMB-45, and SOX-10 [Figure 1]c while being nonimmunoreactive for pancytokeratin. Surrounding salivary parenchyma was unremarkable along with 48 reactive cervical lymph nodes. A diagnosis of melanoma metastatic to intraparotid lymph node was rendered.
|Figure 1: (a) Intraparotid lymph node with large pleomorphic spindled-to-polygonal cells with prominent nucleoli (H and E, ×40). (b) Tumors cells showing immunoreactivity with melan-A (×40). (c) Tumors cells showing immunoreactivity with SOX-10 (×40). (d) Periorbital skin tumor shows similar cells with marked nuclear pleomorphism and prominent nucleoli (H and E, ×40)|
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The patient was reviewed for any suspicious skin lesions, and a pigmented nodule measuring 1.3 cm × 1.0 cm × 0.9 cm was noted in the right periorbital region. The lesion was excised with a margin of 2 mm. Histopathology revealed nodular melanoma in vertical growth phase having maximum tumor thickness of 6 mm and infiltrating subcutis (anatomic level V) [Figure 1]d.
The patient was discharged in a satisfactory condition and is on follow-up.
| Discussion|| |
Cutaneous melanoma is considered rare in childhood, with an Italian study reporting 54 cases of cutaneous melanomas in childhood based on a national registry from 2000 to 2012 and another multi-institutional study from the United States reporting 365 cases during the period from 1953 to 2008: two percent of all cases occur in patients younger than 20 years of age, but only a small number of these develop in prepubertal children. Epidemiologic findings from North American and European registries indicate an incidence of 0.7–0.8 per million population a year in the first decade of life but more than 10 per million in the second.
To render the ominous diagnosis of melanoma in a child is a very difficult decision for clinicians and pathologists. The low frequency and atypical clinical and histologic features of cutaneous melanoma of childhood, combined with a relative lack of reliable pathologic criteria for discrimination between benign and malignant melanocytic lesions, may lead to delayed diagnosis and treatment and may result in impaired patient outcome. In up to 66% of cases, increased mortality has been attributed to late diagnosis.
Risk factors for developing melanoma are same as those in adults and include family history of melanoma, large congenital nevi, numerous nevi, dysplastic nevi, and xeroderma pigmentosum. Also implicated are an association with immunosuppression and survivorship of separate childhood cancers (especially leukemia and retinoblastoma).
In our patient, none of these risk factors was present.
The clinical diagnosis of melanoma in children may be difficult, and the commonly used ABCDE clinical rule (i.e., asymmetry, border irregularity, color variability, dimension >6 mm, and evolution) may prove useless or even misleading. Concerning tumor size, for instance, it is normal for benign nevi to expand and become relatively large as a child grows and possibly develop alarmingly melanoma-like features. Cutaneous melanomas in childhood have a very common presentation as clinically amelanotic lesions, and 7% of melanomas that develop in association with a preexisting nevus are asymptomatic. Differential diagnosis includes Spitz nevi, traumatized common congenital or acquired nevi, pyogenic granuloma, dysplastic nevi, traumatized verrucae, blue nevi, hemangioma, angiokeratoma, thrombosed lymphangioma, keloid, seborrheic keratosis, and pigmented basal cell carcinoma.
When confronted with a pigmented lesion in a pediatric patient, the same histologic principles are used to differentiate between benign and malignant lesions as in adults, namely, size >10 mm, asymmetry, lateral borders poorly demarcated, intraepidermal pagetoid spread of single cells prominent at the center or at the periphery of the lesion, irregular intraepidermal nest formation, “consumption”/atrophy or ulceration of the epidermis, deep extension in dermis/subcutaneous tissue, expansive rather than infiltrative deep border, absence of maturation, diffuse/non-nested sheets of cohesive cells (expansive growth) in the dermis, cellular atypia, and deeply located or atypical mitoses. All these features are suggestive of malignancy and should be evaluated on the whole; none of them, considered independently, can determine or exclude the diagnosis of melanoma in children.
Histologically pediatric melanomas, like melanoma in adulthood, can be classified into various subtypes. The most common subtypes described in literature are superficial spreading and nodular melanoma. Furthermore, acral lentiginous, lentigo maligna, desmoplastic and neurotropic melanomas in addition to small cell melanoma, melanoma with Spitzoid features, malignant blue nevus, and animal type melanoma have been described but are rare. Lentigo maligna melanoma and desmoplastic melanoma are exceedingly rare as they arise from chronic sun exposure and generally only present in childhood in patients with xeroderma pigmentosum. Lesions diagnosed as a melanoma, but unclassifiable subtypes also represent a large part of melanomas in childhood. In a study from 2009, unclassified and Spitzoid melanomas comprised 47% of the melanomas in patients younger than 10 years, followed to severely atypical ambiguous lesions (32%).
IHC may be helpful in selected cases. HMB-45 shows diminished expression toward the base (maturation) with Ki67 labeling index of 1%–2% in Spitz nevi. Diffuse expression of HMB-45 favors Spitzoid melanoma while strong staining is seen in dermal component of nevoid melanomas. Furthermore, the Ki67 labeling index is higher (15%–20%) and is seen throughout the lesion in cases of Spitzoid and nevoid melanomas.
While the rarity of pediatric melanomas precludes establishment of definitive prognostic factors, clinicopathologic type, Breslow thickness, Clark level, radial or vertical growth phase, and ulceration have been found to be related to clinical course in most case series and reviews on pediatric melanoma.
| Conclusion|| |
Cutaneous melanoma in childhood is a rare tumor, but careful analysis of histologic features as well as the additional information provided by IHC should allow for the correct diagnosis in most cases. Pending definitive prospective studies to guide management of this rare tumor, guidelines extrapolated from adult patients will be used for diagnosis and management in the foreseeable future.
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Conflicts of interest
There are no conflicts of interest.
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Department of Pathology, National Reference Laboratory, Dr. Lal PathLabs, Sector - 18, Rohini, New Delhi - 110 085
Source of Support: None, Conflict of Interest: None