An 88-year-old woman with history of several non-melanoma skin cancers and Stage Ib (T2N0M0B1) mycosis fungoides controlled on bexarotene 200 mg/m2 and clobetasol ointment presented for a routine dermatology
follow-up visit. Physical exam revealed a 1 cm, soft, violaceous
dermal nodule on the right orbital rim (Figure 1). The nodule was asymptomatic and had been slowly growing for six months. Clinical differential diagnosis included basal cell carcinoma, cyst, and nodular mycosis fungoides.
A shave biopsy was performed, demonstrating a nodular,
dermal lymphocytic infiltrate on low power (Figure 2). Higher power showed small aggregates of epithelial cells encompassed
by a dense lymphocytic infiltrate (Figure 3). The epithelial cells were strongly pancytokeratin positive. A diagnosis
of lymphoepithelioma-like carcinoma (LELC) was made. T-cell gene rearrangement of the biopsy specimen was positive
for monoclonal amplicons with a profile similar to that of the patient's peripheral blood. Further workup included a non-contrast computed tomography scan of the neck demonstrating
no lymphadenopathy and nasolaryngoscopic exam that was unremarkable.
The neoplasm was successfully cleared with two stages of Mohs micrographic surgery and repaired with a rhombic transposition flap. There was no evidence of recurrence six months post-operatively.
LELC is a malignant neoplasm that histologically resembles undifferentiated nasopharyngeal carcinoma (lymphoepithelioma)
yet occurs outside the nasopharynx. LELC has been found in different tissues including salivary glands, larynx, thymus, stomach, uterine cervix, and skin.1 The association between undifferentiated nasopharyngeal carcinoma and Epstein-Barr Virus (EBV) has been well documented; however, LELC is rarely associated with EBV.2 While typically low-grade, there are reports
of LELC having distant metastases.3
Cutaneous LELC was first reported by Swanson et al in 1988, and over sixty cases have been subsequently published.1,3 It is a rarely-
encountered cutaneous neoplasm that typically presents as a skin-colored to brightly erythematous dermal nodule favoring the head and neck.1 The histopathological differential diagnosis is broad and molecular markers such as cytokeratin are essential for identification.3,4 There are no clearly established guidelines on management of LELC; however, removal of the lesion with Mohs micrographic surgery or wide local excision is essential.5 A thorough otolaryngological examination including flexible laryngoscopy
is required to exclude nasopharyngeal carcinoma.1,5
This is the first case report of LELC occurring in the setting of mycosis fungoides. We hypothesize that the clonal proliferation of lymphocytes seen in the biopsy specimen, while likely reflective
of the patient's known diagnosis of mycosis fungoides, still did not play a role in the development of LELC in this patient.