Abstract:

Mycosis fungoides (MF) is a malignant disease of T-cells. It is the most common cutaneous lymphoma with an annual incidence of 6.4-9.6 cases per million in the United States. Manifestations both clinically and histologically can be notoriously deceiving, as it can resemble a variety of other skin conditions, especially in those with darker skin tones. A 65-year-old male presented with asymptomatic skin hyperpigmentation on various body surfaces which had slowly progressed over a twenty year period. Biopsies taken six and three years prior demonstrated lichenoid dermatitis with dermal pigment-laden macrophages, suggestive of erythema dyschromicum perstans. Physical exam of the trunk and extremities revealed numerous hyperpigmented, slightly atrophic patches and surrounding hypopigmentation. While biopsies over the first 6 years of his disease showed no evidence of cutaneous T-cell lymphoma, clinical suspicion at follow up remained high for MF and punch biopsies were again taken which showed the suspected diagnosis. Results of a specimen from the right shoulder demonstrated a patchy lichenoid infiltrate of atypical lymphocytes. Immunohistochemical staining showed a predominance of CD3/CD4 positive T-cells with a significant loss of CD7 expression. Pathologic diagnosis of MF can be challenging due to highly variable histologic findings, obscuring evidence for diagnosis. Folliculotrophic variants, granulomatous variants, and variants that mimic common dermatoses all create challenges for diagnosis. Given this, multiple biopsies with repetition are often necessary if clinical suspicion remains. In the case of our patient, many years elapsed between symptom onset, initial biopsies, and diagnosis, leaving the opportunity for disease progression. This case classically demonstrates the challenges in both clinical and histopathologic diagnosis of MF, emphasizing the need for persistence in pursuing a diagnosis in cases with progression or those refractory to treatment.

Financial Disclosure:
No current or relevant financial relationships exist.

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Joseph Dodson, BS

Biography