Hairy cell leukemia presenting as a peripancreatic mass: cytomorphology and radiographic correlates.

Hairy cell leukemia (HCL) usually presents with peripheral cytopenias, diffuse marrow infiltration, and splenomegaly. This chronic lymphoproliferative disorder is not typically associated with lymphadenopathy or mass lesions. We report a case of HCL first treated by splenectomy, followed by several years of interferon therapy. Twenty-five years later, the patient presented with weight loss, fatigue, and a large PET-avid mass surrounding the head of the pancreas. Fine-needle aspiration was pursued to investigate the unusual and infiltrative appearance of the lesion, which was suggestive of another primary malignancy. Cytology smears showed discohesive lymphoid cells with round nuclei and delicate cytoplasmic projections. Flow cytometry confirmed the presence of a clonal B-cell population with bright expression of CD20 as well as CD25 and CD103, diagnostic of HCL. This is the first report of HCL presenting as a peripancreatic mass. The importance of correlation with radiology and clinical history is emphasized when evaluating such lesions.

Large cell transformation of mycosis fungoides on fine needle aspiration: an unusual case mimicking classical Hodgkin lymphoma.

Mycosis fungoides (MF), the most common type of primary cutaneous T-cell lymphoma, undergoes large cell transformation in only a minority of cases that present in patch stage. We describe a 52-year-old patient with a history of unilesional patch stage MF treated with localized radiotherapy. He had disease recurrence 5 years later and began psoralen plus ultraviolet A treatment with good response. After inguinal lymphadenopathy was detected on physical examination, a follow-up PET scan showed a fluorodeoxyglucose-avid inguinal node, which was evaluated by fine needle aspiration. Cytomorphology showed numerous Reed-Sternberg-like cells, highly suspicious for Hodgkin lymphoma. Histologic sections revealed isolated sinusoidal involvement by pleomorphic CD30-positive tumor cells, diagnostic of large cell transformation of MF in light of clinical history. The cells were also positive for CD15 and CD4. This case emphasizes morphologic features of an entity with limited description in the cytology literature and adds to the growing number of reported CD15-positive T-cell lymphomas.

Rapidly progressive cutaneous Rhizopus microsporus infection presenting as Fournier's gangrene in a patient with acute myelogenous leukemia.

Members of the genus Rhizopus within the class Zygomycetes can cause devastating opportunistic infections. Cutaneous disease arising from direct inoculation of fungal spores has the potential to disseminate widely. Here, we describe a dramatic case of cutaneous Rhizopus infection involving the penis in a patient with acute myelogenous leukemia. Despite aggressive surgical debridement, systemic antifungal therapy, and donor lymphocyte infusion, the infection was ultimately fatal. This case illustrates the unique diagnostic and therapeutic challenges in the clinical management of cutaneous Rhizopus infection.