Clinical Findings: A 45-years old Caucasian male with Down syndrome presented a 2 weeks history of multiple firm nodules up to 4 x 3 cm and erythematous patches and plaques on the face, chest, abdomen, upper leg, and upper arms. The patient has a history of venous thromboembolism and diabetes mellitus. The patient was given Bactrim under the impression of cyst rupture but the lesions were persistent. A skin biopsy was performed from the upper back lesion. Family history of various malignant neoplasms among siblings has been informed by his dermatologist.
Pathology Findings: A skin biopsy showed a pandermic dense perivascular nodular as well as interstitial infiltrate of mononuclear cells. Papillary dermis and the epidermis appeared to be busy. The dermal infiltrate showed intermediate and large cells with round nuclei, fine chromatin and inconspicuous nucleoli, which resembled a lymphoblast. Adnexal structures were spared. Frequent mitosis was observed. Considering that patients with Down syndrome have a higher risk of leukemia, in particular megakaryoblastic leukemia and acute lymphoblastic leukemia, together with cytological features, I could narrow down immunomarkers toward ALL. However, there was a morphological distractor, the epidermal changes. The epidermis showed lichenoid process with exocytosis of lymphocytes. The infiltrating lymphocytes, however, appeared mature forms and a reactive process possibly drug-related was considered rather than a leukemic involvement. In addition, this consideration also can be supported by fact that any type of leukemia cutis tends not to involve the epidermis.
Immunohistochemical studies showed that the tumor cells were CD3+, CD2+, CD5+ and CD7+ T-cell linage. Subset of tumor cells was positive for CD4 but the majority of tumor cells were negative for both CD4 and CD8. The epidermal infiltrate was a mixed population of CD4+ and CD8+ T-cells, supporting the reactive process. Subset of tumor cells was positive for TdT, TCR beta, and PD1 (weak). The tumor cells were negative for B-cell markers (CD20 and PAX5), CD30, EBERS, CXCL13, CD56, CD1a, and CD34. The overall immunophenotype supported a precusor T-cell lineage.
Flow cytometry analysis of peripheral blood showed also aberrant precursor T-cells, which were 80% of lymphocytes (20% of white cells), c/w T-cell lymphoma. Tumor cells were positive for CD3, CD2, CD5, CD7, CD45, Cd38, and αβTCR. Tumor cells were negative for CD4, CD8, CD10, CD19, CD20, CD23, CD24, KAPPA, LAMBDA, CD11B, CD11C, CD14, CD25 , CD34, CD56, CD103, γδTCR.
Follow-Up: One month after the dermatology visit, the patient had been transferred to Nebraska Medical Center with respiratory failure and acute kidney injury. On the admission chest X-ray, the perihilar infiltrates and a wide mediastinum consistent with lymphadenopathy were detected. No additional studies were performed. For 2 days resuscitation, the patient passed away due to the ARDS, pneumonia and septic shock.