Pathology/<scp>CPC</scp>

Aim: Lymphocytic thromobophilic arteritis (LTA) is a distinctive but poorly understood lymphocytic vasculitis.We conducted a review of patients with LTA at St Vincent's Hospital, Melbourne to better define this entity.Methods: Documented cases of LTA were assessed for demographic data, relevant comorbidities, clinical features, histopathology, treatments, and clinical response.Results: Forty cases were collated including 31 (77.5%)female and 9 (22.5%)male patients.The average age of onset was 32.5 (2-63) years.Sixteen (40%) of patients were Asian.Thrombophilic serological abnormalities were found in 18 (45%).The most common presentation was widespread livedo racemosa (37/92.5%)which had a characteristic distribution over the limbs, buttocks and lower trunk.Acral involvement was prominent in all cases.A macular pigmented rash was found in 8 (20.0%) patients.Five (12.5%) had a fine petechial eruption.Eleven (27.5%) had ulceration with clinical and histological features consistent with livedoid vasculopathy.Nine (22.5%) had evidence of peripheral neuropathy.Thirty-four (85.0%) had a biopsy; most demonstrated lymphocytic infiltrate involving the deep dermis (n = 22, 64.71%), with a predilection for small (n = 23, 67.7%) and medium-size (n = 21, 61.8%) vessel involvement.Eleven (32.4%) reported a distinct fibrin ring, while 18 (52.9%)had a less distinct pattern of fibrin deposition.Most received aspirin (n = 36, 90.0%) and/or pentoxifylline (n = 25, 62.5%), and 5 (12.5%) received rivaroxaban.Nine received immunosuppressive therapy prior to diagnosis and 3 for treatment of LTA.While most clinical signs responded well to therapy, livedo racemosa persisted indefinitely in all patients consistent with permanent damage to affected vessels.Macular pigmentation faded or cleared and ulceration healed in all cases.Symptoms of peripheral neuropathy responded in 56% (5/9) of cases. Conclusion:LTA has distinctive clinicopathological features and may lie on a spectrum with livedoid vasculopathy.Although livedo racemosa persists indefinitely, other manifestations respond to treatments targeting thrombophilic pathogenic factors.