Breast fat necrosis secondary to warfarin-induced calciphylaxis, a rare mimicker of breast cancer: A case report and a review of literature

Breast fat necrosis (BFN) is usually a benign inflammatory response to breast trauma. However, an extremely rare cause of fat necrosis is calciphylaxis, a calcification of small- and medium-sized arteries causing thrombosis and ischemia. It is classified into (A) uremic (B) nonuremic-induced calciphylaxis. Calciphylaxis has been reported to be encountered in different parts of the body. However, to the best of our knowledge there is only one case in the English literature of BFN 2ry to warfarin-induced calciphylaxis. We report a 65-year-old female, known case of atrial fibrillation on warfarin, presented with a left breast mass of 4-month duration. The mass was painful and progressively enlarging. Examination of the left breast showed 7 × 4 cm mass, spanning from 10-2 o'clock, free from surrounding structures, with preserved overlying skin. However, the mass was not visualized on mammogram. Ultrasound showed a left breast lobulated hypoechoic mass containing a hyperechoic component. Biopsy showed fat necrosis. After 1 month, she presented with ulceration of the overlying skin. After wide local excision, histopathology demonstrated a calciphylaxis-induced fat necrosis. Considering the patient's background, the diagnosis was BFN secondary to warfarin-induced calciphylaxis. Hence, the warfarin was shifted to Rivaroxaban, 6 months follow-up showed no evidence of recurrence. In conclusion, the rarity of nonuremic calciphylaxis is reflected on the delay of diagnosis in some of the reported cases and the lack of grading system used to guide the management of such difficult wounds. However, keeping a high index of suspicion is important whenever such wounds are encountered with presence of risk factors other than end-stage kidney disease.

Assessment of outcomes of calciphylaxis

BACKGROUND

Calciphylaxis is a rare thrombotic vasculopathy characterized by high morbidity and mortality. There is a paucity of studies examining longitudinal outcomes.

OBJECTIVE

To assess mortality, days spent in the hospital, and amputations in patients with calciphylaxis.

METHODS

A retrospective medical record review was conducted in 145 patients diagnosed with calciphylaxis at an urban tertiary care hospital from January 2006 to December 2018.

RESULTS

Six-month mortality was 37.2%, and 1-year mortality was 44.1%. Patients with nephrogenic calciphylaxis had worse survival than those with nonnephrogenic calciphylaxis (P = .007). This difference in survival disappeared when limiting mortality to deaths due to calciphylaxis. Age (P = .003) and end-stage renal disease (P = .01) were risk factors associated with 1-year mortality. Diabetes mellitus was associated with greater total hospitalization days (coefficient, 1.1; 95% confidence interval, 1.01-1.4); bedside debridement was associated with fewer hospitalization days (coefficient, 0.8; 95% confidence interval, 0.7-0.9). Amputations were not associated with any of the examined risk factors. The use of warfarin followed by a transition to nonwarfarin anticoagulation was associated with decreased hazard of death (P = .01).

LIMITATIONS

Retrospective nature.

CONCLUSIONS

Calciphylaxis remains a complex, heterogeneous disease. Mortality is lower in patients with nonnephrogenic disease. These findings may be incorporated during discussions regarding the goals of care to facilitate informed shared decision making.