Case 9

Clinical History:

• 28 yo female with an atypical pigmented lesion on the back.

Case 9

Diagnosis:

• A: Superficial spreading melanoma with regression

• B: Melanoma with in invasive spindle cell component

• C: Recurrent naevus

• D: Lentiginous compound dysplastic naevus

• E: Invasive extramammary Paget’s disease

Case 9

Additional Clinical History:

• Histological impression concerning for SSMM

• Additional clinical information at MDM: Previous removal of a pigmented lesion at this site by GP

• Specimen discarded and not sent to Pathology

Case 9

Diagnosis:

• A: Superficial spreading melanoma with regression

• B: Melanoma with in invasive spindle cell component

• C: Recurrent naevus

• D: Lentiginous compound dysplastic naevus

• E: Invasive extramammaryPaget’s disease

Recurrent Naevus -Introduction-

• Repigmentation within a scar due to regrowth of melanocytes following incomplete removal of benign naevus

• Most frequently following shave biopsy of common acquired naevi but also congenital and dysplastic naevi

• Time course: weeks to few months (<6 months)

Recurrent Naevus -Clinical-

• Wide age range

• Most commonly before age 40 years

• F>M

• Predilection for back

Recurrent Naevus -Diagnosis-

• Prior history of trauma/surgery

• Time course

• Review of previous Pathology

Recurrent Naevus -Differential Diagnosis-

Superficial spreading melanoma:

• Reliable separation possible only in the context of appropriate clinical and histological features