A SMALL AMELANOTIC NODULE ON THE FRONT 

Josep Malvehy, A. Barreiro

Dermatology Department

Melanoma Unit

Hospital Clinic of Barcelona, Spain

Case presentation: a 72-year-old woman with previous cutaneous melanoma on the left leg 20 years ago (stage IIA), familial melanoma syndrome and carrier of a mutation in CDKN2A. In one of the follow visits she presented with two small amelanotic lesions in the front (4 and 2 millimetres in diameter) (Figure A).  The patient was not aware of changes in the lesions. 

FIgure A

Diagnostic work up, treatment and follow up

Dermoscopy showed in the larger lesion a asymmetric pink and bluish coloration with atypical polymorphous vessels (figure B). The other small lesion showed an unspecific pattern and polymorphous vessels (Figure C).

Figure B

Figure C

With the clinical diagnosis of nodular melanoma and melanoma skin metastasis, both lesions were excised. Histopathology confirmed a non-ulcerated nodular melanoma with Breslow thickness of 1,2 mm with no mitosis, BRAF wild type (Figures D-G).

Figure D

Figure E

Figure F

Figure G

The small lesion corresponded to dermal metastasis (Figure H). Blood tests, brain MRI and CT scan of the neck, thorax and abdomen were normal. With these results a melanoma stage IIIB (T2, N2c, M0) was concluded (AJCC 2010).

Figure H

Wide excision of the two lesions with one centimetre of margin and advancement flap was performed. After 6 weeks of the surgery the tumour relapsed with multiple small skin metastases on the frontal face and scalp in 3 centimetres around the surgical scar. The patient was treated topically with imiquimod (daily during 4 wks and 5 times weekly once the treated site had become intolerably erythematous and inflamed) with complete clinical response.  Follow-up with physical examination, digital dermoscopy with photographic documentation of the skin, blood tests and sonography of the neck (every 3 months) and brain MRI and thorax and abdomen CT scanners (every 6 months) were normal during two years. In one of the visits the patient presented a new brown pigmented lesion (2,5 millimetres) resembling a dermal nevus on the frontal scalp at 2 centimetres of the primary tumour (Figure I). Dermoscopy showed a nevoid brown globular pattern (Figure J). The lesion was excised and histopathology showed a small skin metastasis. The patient was treated again with imiquimod of the area with the same schedule.  At the moment after 6 weeks no new lesions have appeared.

Figure I:

Figure I

Figure J:

Figure J

Key message

  • Fast growing melanomas may mimic benign lesions at the initial stage.
  • Atypical vessels in dermoscopy are diagnostic clues in hypo-pigmented melanoma. Skin metastasis have different patterns and they may mimic clinically and dermoscopically benign lesions including dermal or blue melanocytic nevi or angiomas.
  • Physical examination and dermoscopy with photographic documentation of the skin is essential to rule out skin metastasis.
  • Topical imiquimod either in monotherapy or in combination with cryosurgery, retinoids or other immunotherapies can be useful to treat multiple small melanoma skin metastases in selected patients.

References

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2. Podlipnik S, Carrera C, Sánchez M, Arguis P, Olondo ML, Vilana R, Rull R, Vidal-Sicart S, Vilalta A, Conill C, Malvehy J, Puig S. Performance of diagnostic tests in an intensive follow-up protocol for patients with American Joint Committee on Cancer (AJCC) stage IIB, IIC, and III localized primary melanoma: A prospective cohort study. J Am Acad Dermatol. 2016. pii: S0190-9622(16)01496-1

3.Costa J, Ortiz-Ibañez K, Salerni G, Borges V, Carrera C, Puig S, Malvehy J.
Dermoscopic patterns of melanoma metastases: interobserver consistency and accuracy for metastasis recognition. Br J Dermatol. 2013 Jul;169(1):91-9

4. Rivas-Tolosa N, Ortiz-Brugués A, Toledo-Pastrana T, Baradad M, Traves V, Soriano V, Sanmartín V, Requena C, Martí R, Nagore E. Local cryosurgery and imiquimod: A successful combination for the treatment of locoregional cutaneous metastasis of melanoma: A case series. J Dermatol. 2016 May;43(5):553-6