P567\u2005Leukaemia cutis: a rare manifestation of acute lymphoblastic leukemia

Abstract

Leukaemia cutis is a broad term used to describe any cutaneous presentation of leukaemia. It is the infiltration of neoplastic leukocytes or their precursors into the epidermis, the dermis, or the subcutis. The appearance of these lesions is variable and may include flesh–coloured to violaceous papules, plaques, or nodules. We present the case report of a 4-year-old Caucasian girl who presented with a cutaneous lesion which ultimately led to the diagnosis of leukaemia (ALL). Our patient first presented to the Emergency Department of her local unit with complaints of right ankle pain and swelling which persisted after a minor injury. She was treated conservatively, and pain resolved over a month. FBC was normal, and she had a CRP of 31 and an ESR of 83, which were normal on repeat bloods after 2 weeks. She represented 4 months later complaining of painful wrists. There was a well-demarcated soft tissue swelling above the right supraorbital ridge, which was raised, had a bluish hue and measured approximately 3 × 1 cm. Parents had initially noticed an area of hypopigmentation which subsequently developed into the swelling described. There was no history of weight loss, pallor, easy bruising, night sweats or excessive fatigue. She was a previously healthy child. She was admitted for medical investigations to out rule connective tissue disorders and malignancy. Blood investigations were normal and abdominal ultrasound showed no masses or hepatomegaly. Cranial CT imaging revealed a 3 × 1 cm soft tissue swelling with no attachment to the underlying bone. A biopsy of the rapidly enlarging lesion revealed blasts cells, consistent with a diagnosis of precursor B-cell leukaemia. Subsequent blood tests confirmed the presence of circulating blasts, despite serial full blood counts over the previous 7 months being normal. She was commenced on UK ALL Regimen A Protocol. The skin lesion involuted with treatment. The annual incidence of leukaemias in children is 4.5 cases per 100,000 children. Acute lymphoblastic leukaemia accounts for approximately 77% of cases. The common presentations in this age group are pallor, irritability and bone pain. Leukaemia cutis can be a rare presenting sign of ALL (3% of cases).