Pathology of Spitz Nevus,
Atypical Spitz Nevus and
Sophie Spitz, in 1948, for the first time established the criteria to distinguish Spitz nevus from melanoma.
Spitz nevus 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 nevus may be junctional, compound or intradermal.
The majority of Spitz nevi are compound lesions.
Microscopic images of Spitz Nevus:
More microscopic images of Spitz Nevus:
Pathology of Atypical Spitz Nevus:
This lesion displays architectural and cytological atypia to a degree beyond to what is accepted as a benign Spitz nevus.
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.
clues to Atypical Spitz Nevus:
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
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.
Read related post: Desmoplastic Spitz Nevus
Morphological features provide valuable clues to the underlying genetic aberrations in spitzoid neoplasms.
Genetic aberrations can be found in the entire biological spectrum of spitzoid neoplasms (i.e. Spitz nevi, atypical Spitz tumors and spitzoid melanoma) and are, therefore, probably not useful for distinguishing benign from malignant tumours.
Genetic aberrations represent vital targets for therapeutic interventions and offer investigational treatment options for patients with metastatic disease.
The appearance of multiple epithelioid melanocytic tumors with BAP1 loss indicates a hereditary tumour syndrome.
Immediate genetic counselling and preventive screening of affected individuals is necessary in these cases.
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
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