B. Cutaneous leukocytoclastic vasculitis
The histopathologic findings from a lesional skin biopsy specimen revealed neutrophilic infiltration of the small blood vessels in the skin along with necrosis and extravasation of the red blood cells (Figure, C). The findings from a biopsy specimen of a lung lesion revealed small cell carcinoma. The patient was diagnosed with extensive-stage small cell lung cancer and began systemic chemotherapy with cisplatin and etoposide. Unfortunately, the patient died soon after the first dose of chemotherapy due to neutropenic sepsis.
Cutaneous manifestation of an internal malignant neoplasm may present as direct infiltration into the skin or may present indirectly as a paraneoplastic syndrome (PNS).1 The Curth postulates are the cornerstone for defining the association between internal malignant neoplasms and cutaneous disorders.1 Leukocytoclastic vasculitis is a histopathologic term denoting vasculitis of the small vessels with predominantly neutrophilic infiltrate.2 After degranulation, the neutrophils undergo apoptosis, a process known as leukocytoclasis, releasing nuclear debris, which is also called nuclear dust.2 According to the consensus statement developed at the Chapel Hill Conference on Nomenclature of Systemic Vasculitis in 1994, cutaneous leukocytoclastic vasculitis (CLV) is defined as an“[i]solated cutaneous leukocytoclastic angiitis without systemic vasculitis or glomerulonephritis.”2,3 As a PNS, CLV is the most commonly diagnosed vasculitis (45%) followed by polyarteritis nodosa (36.7%).4 Cutaneous leukocytoclastic vasculitis occurs most frequently with hematologic cancers followed by lung, gastrointestinal, or urinary tract tumors.5,6 Approximately 20% to 26% of patients with paraneoplastic CLV have lung cancer.4,6 Among lung cancers, adenocarcinoma and squamous cell are most commonly associated with CLV.4,6,7