Spitz Nevus

Path Quiz Case- 34

Dr. Sampurna Roy MD

Sophie Spitz , in 1948, for the first time established the criteria to distinguish Spitz naevus from melanoma. Spitz naevus mostly occurs in children and young adults. Clinically, the tumour presents as a pink or flesh coloured papule or nodule, located on the face, trunk or extremities. Histologically, Spitz naevus may be junctional, compound or intradermal. The majority are compound lesions.
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DIAGNOSTIC CRITERIA

Major criteria

Minor criteria

1. Symmetry and sharp lateral borders (no lateral extension of junctional activity beyond the limits of dermal components). Silhouette symmetry: an unsupportable histologic criterion for distinguishing Spitz nevi and compound nevi from malignant melanoma.Arch Pathol Lab Med. 1997 Jan;121(1):48-53.
2. Cell type- epithelioid and spindle cells. Spindle cells are more common. These cells are arranged in fascicles with vertical orientation related to the rete ridges.
3. Maturation of cells (presence of small normal nevus cells in the deeper part of the lesion).
4. Absent pagetoid spread of single cells.
5. Coalescent, pale pink Kamino bodies. Multiple step sections may be necessay. These are PAS and trichrome positive. Eosinophilic globules in spitz nevi: no evidence for apoptosis.Am J Dermatopathol. 1998 Dec;20(6):551-4.

1. Junctional clevage
2.Hyperkeratosis and acanthosis.
3. Superficial multinucleate naevus cells
4. Perivascular inflammation
5. Absence of nuclear pleomorphism
6. No deep atypical mitoses (mitosis may be present in the junctional and superficial component.
7. Deep outlying, solitary naevus cells. Naevus cells drift inbetween collagen fibres.
8. Superficial edema, telangiectasia present.
9. Stratification of HMB-45 and cyclin D1 staining.
10.Low PCNA staining (only 2-3% of cells display Ki-67 in contrast to 15% in melanoma, p53 is expressed in occasional Spitz naevi).

Atypical Spitz Naevus:
This lesion displays architectural and cytological atypia to a degree beyond to what is accepted as a benign Spitz naevus. However, the features do not amount to clear cut malignant melanoma. Atypical features may be subdivided into those involving the epidermis or the dermis/subcutis.

"Atypical" Spitz's nevus, "malignant" Spitz's nevus, and "metastasizing" Spitz's nevus: a critique in historical perspective of three concepts flawed fatally.Am J Dermatopathol. 2004 Aug;26(4):310-33.

Cutaneous melanoma and atypical Spitz tumors in childhood.Cancer. 1995 Nov15;76(10) : 1833-45.

Diagnostic clues to Atypical Spitz Naevus:

                      I -Intradermal variant:
A. Architectural disorder-
          1. Disordered intraepidermal melanocytic proliferation (lentiginous and junctional nests).
          2. Asymmetry
          3. Poorly circumscribed
          4. Lateral extension of intraepidermal component.
B. Cytological atypia-
Nuclear pleomorphism and enlargement. Variation in nuclear chromatin pattern and nucleoli.
C. Host response-
Patchy chronic inflammation and fibroplasia.

                     II -Dermal variant:
A. Architectural disorder-
Expansile nodule, increased cellularity,asymmetry, loss of cellular cohesion, deep extension, lack of maturation, ulceration, necrosis.
B. Cytological atypia
C. Numerous atypical mitosis and mitosis at base of lesion.

GRADING SYSTEM: Spitz tumors in children: a grading system for risk stratification.Arch Dermatol. 1999 Mar;135(3):282-5.abstract
Some authors have advocated a grading system to assess Atypical Spitz nevus:

Spitz tumour is categorized into:
1. Low 2. Intermediate and 3. High risk groups.

Parameters studied for grading are as follows:
1. Age more than 10 years.
2. Diameter of lesion more than 10mm.
3. Presence of ulceration.
4. Involvement of subcutaneous fat (level V)
5. Mitotic figures atleast more than 6 /mm2.

Spitzoid melanoma:
This is malignant melanoma composed of spindle or epithelioid cells, and share morphological features in common with Spitz naevus. The tumour has an aggressive behaviour and lead to metastasis.

Diagnostic clues to Melanoma:
1. Lack of maturation of cells at the base.
2. Presence of numerous deep or atypical mitoses.
3. Intraepidermal melanocytes (epithelioid) below parakeratosis. Presence of pagetoid spread of melanocytes.
4. Dermal nests larger than junctional nests.
5. Deep extension in a bulbous manner into the fat (Clark level V).

1. Halo Spitz nevus: abstract; 2. Desmoplastic Spitz nevus; 3. Plexiform Spitz nevus abstract ; 4. Pagetoid Spitz nevus abstract ; 5. Angiomatoid Spitz nevus abstract ; 6.Hyalinizing Spitz nevus abstract ; 7. Recurrent Spitz nevus: abstract

Abstracts:

-Classic and atypical Spitz nevi: review of the literature.Cutis. 2007 Feb;79(2):141-6.

-Expression of c-kit (CD117) in Spitz nevus and malignant melanoma.J Cutan Pathol. 2006 Jan;33(1):33-7.

-The spectrum of Spitz nevi: a clinicopathologic study of 83 cases.Arch Dermatol. 2005 Nov;141(11):1381-7.

-A case of Spitz nevus with multiple satellite lesions.J Am Acad Dermatol. 2005 Feb;52(2 Suppl 1):48-50.

-Cutaneous melanocytic lesions: selected problem areas.Am J Clin Pathol. 2005 Dec;124 Suppl:S52-83.

-Spitz nevus is relatively frequent in adults: a clinico-pathologic study of 247 cases related to patient's age.Am J Dermatopathol. 2005 Dec;27(6):469-75.

-Spitz naevus versus Spitzoid melanoma: when and how can they be distinguished? Pathology. 2002 Feb;34(1):6-12.

-Spitz naevus: histological features and distinction from malignant melanoma. Australas J Dermatol. 1997 Jun;38 Suppl 1:S49-53.

- Melanomas that simulate Spitz's nevi histopathologically (and vice versa): an exercise in differentiation based on dependable criteria. Dermatopathology. Practical and Conceptual 1999 ; 5 : 9-13

- Spitzoid tumours: a matter of perspective? Am J Dermpathol 2004; 26 (1): 1-3

- Spitz nevus and its histologic simulators. Adv Anat Pathol 2002; 9 (4): 209-21

- Spitz nevus: a look back and a look ahead. Adv Dermatol 2000; 16:81-109; discussion110.

IMAGE LINKS: (Dr Weems): click 1 ; click 2 ; click3 ; click4 ; click5 ; click6 ; click7 ; click8 .