Trifluridine/tipiracil has been approved for the treatment of refractory metastatic colorectal cancer. Adverse effects of this drug combination include leukopenia, neutropenia, fatigue, diarrhea, and vomiting. We present a case of trifluridine/tipiracil-induced leukocytoclastic vasculitis (LCV) with late-onset Henoch-Schönlein purpura (HSP) in a 42-year-old man with metastatic appendiceal cancer. The patient's biopsy-proven LCV developed one month after he began trifluridine/tipiracil treatment and resolved after discontinuation of the drug. He presented to the emergency department two months after the appearance of his LCV with shortness of breath, elevated blood pressure, elevated creatinine, hematuria, and proteinuria. A kidney biopsy was performed and the presence of IgA deposits and cellular crescents indicated rapidly progressive glomerulonephritis secondary to Henoch-Schönlein purpura (HSP). Neither LCV nor HSP have been reported as adverse effects of trifluridine/tipiracil treatment. Malignancy as a cause of our patient's HSP is another possibility. The delay between our patient's skin findings and acute renal failure indicates that suspected HSP should be monitored by urinalysis for a period of time owing to the risk of life-threatening renal disease.

Schnitzler syndrome is a rare disease characterized by chronic urticaria and a monoclonal gammopathy, most commonly IgM with light chains of the kappa type. There are currently no known risk factorsassociated with development of the disease. We report a case of Schnitzler syndrome in a 48-year-old man with a family history of monoclonal gammopathies. The patient’s disease has been well controlled with anakinra therapy. Our case may contribute to a better understanding of the etiology of Schnitzler syndrome as his history could suggest a hereditarypredisposition for the disease. Further studies are necessary to determine whether a genetic component of Schnitzler syndrome exists, as first-degree relatives of patients with monoclonal gammopathies may be at risk for the development of the disease.

Primary cutaneous CD4+ small/medium-sized pleomorphic T-cell lymphoproliferative disorder (PCSM-LPD) is a rare and low-grade form of cutaneous T-cell lymphoma (CTCL), representing 2% of all primary cutaneous lymphomas. Because of its rarity, the etiology or exact clinicopathology of PCSM-LPD remains unclear. We present the first case of PCSM-LPD, to our knowledge, arising at a past melanoma excision site. A 72-year-old woman with a past medical history significant for melanoma-in-situ excised 36 years ago presented to our clinic for evaluation of a single, erythematous plaque of the posterior arm within a melanoma excision scar. A biopsy was performed, revealing PCSM-LPD. Reports of the development of other T-cell lymphoproliferative disorders after prior skin trauma such as chemical burns, thermal injury, and mechanical trauma exist in the literature. Physicians should be aware of the possibility of the appearance of T-cell lymphoproliferative disorders at the site of scars or prior trauma with a time lag of months to years.

Mycosis fungoides (MF), the most common cutaneous T-cell lymphoma, classically has an indolent clinical course, with lesions slowly progressing from patch to plaque to tumor stage. In some cases, the late stages of disease involve extra-cutaneous dissemination to lymph nodes or viscera. Although this "Alibert-Bazin" type is the prototypic MF, there are several variants and subtypes of MF that may have different clinical implications for treatment and prognosis. We describe a woman whose disease course involved a variety of histopathologic and immunophenotypic variants including folliculotropic MF, granulomatous MF with loss of CD8, and then finally CD4/CD8 double-negative MF with large cell transformation and extra-cutaneous dissemination. Clinically her disease behaved as classic indolent stage IA MF for nearly two decades before transitioning to tumor stage and then, finally, involving the lungs and leptomeninges. It is important for physicians to be aware of the clinically relevant variants of MF as well as the possibility of transformation of previously stable disease both clinically and histopathologically.