A 37-year-old white woman on over 10 years of immunosuppressive
therapy for two successive renal transplants
was seen in our dermatology clinic for a tender
lesion on her left eyebrow which had grown rapidly over the
previous few months. Physical exam revealed a 4 mm, pink,
tender papule with a 9 mm subcutaneous component (Figure
1a). There was no lymphadenopathy.
Excisional biopsy showed a dermal nodular malignant neoplasm
with spindled and epithelioid malignant cells with
frequent mitoses without an epidermal connection (Figure 1 b
and c). Immunohistochemical staining confirmed the diagnosis
of malignant melanoma, with a Breslow depth of at least 6 mm
and Clark level of at least IV. Subsequent complete skin exam
revealed no cutaneous primary lesion. A PET scan was negative
for metastatic disease.
The case was discussed at our institution's cutaneous oncology
tumor board by a multidisciplinary team including transplant
nephrology, dermatologic surgery, dermatopathology, surgical
oncology and plastic surgery. The consensus diagnosis was primary
dermal melanoma. Given the cosmetically sensitive area
in a young woman, excision with 1 cm margins was recommended
along with sentinel lymph node biopsy (SLNB).
The excision showed no residual tumor, and the SLNB was
negative. Skin graft repair was performed to allow close monitoring
for recurrence. With a classic melanoma of this depth,
recommendations might be to stop immunosuppression and
sacrifice the transplanted kidney for a potentially increased
chance of survival, though this is controversial. In this case the
multidisciplinary decision was to decrease, but not stop, immunosuppression.
Mycophenolate mofetil was discontinued,
but the patient's other immunosuppressants were maintained.
There is no evidence of disease at 17 months.
The diagnosis of primary dermal melanoma was made in
this case based on the solitary focus of dermal disease, lack
of epidermal connection and the absence of a primary epidermal
lesion. Primary dermal melanoma has been reported as a
subtype of melanoma1 that may have a better prognosis than
classic melanomas of equal thickness.1,2,3,4,5 The true origin of
primary dermal melanoma is unknown.1 Bowen et al. hypothesized
that these tumors may originate from non-epidermal
melanocytes, embryological remnants, or deeper appendageal-
associated melanocytes.3 Published data show that these
tumors do not behave like stage IV metastatic disease in skin
from an unknown primary site, but instead correspond to fiveyear
survival rates ranging from 80 percent to 100 percent in
some case series.1-5
Some melanomas may be quite sensitive to immune system
control. In reports, advanced melanoma has regressed upon
withdrawal of immunosuppression.6,7 Likewise, quiescent metastatic
melanoma has been unwittingly transplanted, leading
to the death of the immunosuppressed organ recipient.8 In this
case, immunosuppression was decreased but not withdrawn.
This case of a thick dermal melanoma in a renal transplant
patient raised complex issues regarding prognosis and management.
A multidisciplinary team was necessary to weigh
competing risks and benefits. The patient remains under close
monitoring with a still uncertain long-term prognosis.
The authors would like to thank Dr. George F. Murphy, who provided
an expert opinion in this case.
The authors have no relevant conflicts of interest to disclose.