Results
Demographics
Fifty-six percent (26/46) of patients were male. The average age at diagnosis of leukemia was 58 years (range, 8.5 months–84 years). Eighty-five percent of patients were white (39/46), 11% were black (5/46), 2% were Hispanic (1/46), and 2% were of unknown ethnicity (1/46).
Eighty percent (37/46) of patients with LC had AML; 3 of these patients had a prior diagnosis of chronic myeloid leukemia (CML) and 2 had myelodysplastic syndrome (MDS) that did not develop LC until after they had transitioned to AML. Other subtypes of leukemia in this patient population included acute lymphoblastic leukemia (ALL)(n=2), plasma cell leukemia (PCL)(n=2), undifferentiated leukemia (n=2), chronic lymphocytic leukemia (CLL)(n=1), myelodysplastic syndrome (n=1), and Burkitt-type leukemia (n=1).
Distribution and Morphology of LC Lesions
The clinical appearance of LC was widely variable in morphology and anatomic location (Table 1 and Figure). Eighty-four percent of LC occurrences involved more than one lesion (n=32); 14% were a solitary lesion (n=6). For the 2 patients who had 2 separate episodes of LC, the initial presentation of LC was multiple lesions; recurrent LC at relapse presented as a solitary lesion in both cases. Most LC lesions (77% [67/87]) occurred on the trunk or extremities; 23% (20/87) of LC lesions occurred on less common sites, such as the groin, face, hands, feet, and mucosa. Papules (38% [22/58]) and nodules (31% [18/58]) were the most common morphology; macules, plaques, and ulcers were observed less frequently. Clinical descriptions of LC lesions varied widely, with the most common descriptive characteristics being erythematous (57% [20/35]), violaceous (31% [11/35]), and asymptomatic (84% [32/38]). Rare descriptors included flesh colored, hyperpigmented, tender, pruritic, edema, crusting, and confluent erythematous.
Clinical presentation of leukemia cutis. A, Erythematous papules on the trunk. B, Violaceous infiltrative plaques on the chest. C, Violaceous firm nodule on the oral mucosa. D, Violaceous infiltrative plaques on the breast. E, Erythematous firm nodules on the occipital scalp.
Interval Between Leukemia Diagnosis and LC Diagnosis
Approximately 59% (n=27) of patients had LC as a presenting finding of their leukemia (Table 2). Twenty-two percent (n=10) developed LC at the time of leukemia relapse; 20% (n=9) developed LC during consolidation or salvage chemotherapy. Two AML patients had recurrent episodes of LC both at initial presentation of leukemia and when AML relapsed. Two other AML patients received a diagnosis of LC at the same time as a negative concurrent bone marrow biopsy (ie, aleukemic LC). Mean duration between diagnosis of leukemia and diagnosis of LC was 0.4 months (CLL), 1.0 month (ALL), 4.7 months (AML), and 7.15 months (PCL). In cases of MDS and CML transformation to AML, the interval was 6.5 and 4.9 months, respectively.
Interval Between LC Diagnosis and Death
As a whole, 17% (n=8) of patients were living at the time this article was written (eTable). Of patients who are still living, 10.9% (n=5) have AML. Looking at the cohort of patients with AML and LC, average age at AML diagnosis was 59.8 years. Average time from diagnosis of leukemia to death was 17.3 months (range, 0.6–49.6 months) for AML; 17.0 months (range, 10.0–24.0 months) for CML transformation to AML; 15.0 months (range, 12.0–18.0 months) for PCL; 14.75 months (range, 11.0–18.5 months) for undifferentiated leukemia; and 8.95 months (range, 4.2–13.7 months) for MDS transformation to AML. The interval between leukemia diagnosis and death was notably shorter for the CLL patient (4.0 months) and the deceased ALL patient (2.4 months). Mean duration between LC diagnosis and death was 11.7 months (AML), 11.2 months (undifferentiated leukemia), 9.9 months (CML transformation to AML), 2.75 months (PCL), and 2.4 months (MDS transformation to AML). The shortest intervals between LC diagnosis and death were seen in CLL (0.5 months) and ALL (0.4 months).
