{'fraction_non_alphanumeric': 0.02564102564102564, 'fraction_numerical': 0.008974358974358974, 'mean_word_length': 5.143700787401575, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Encapsulated Fat Necrosis after Lipolysis of the Calf with Phosphatidylcholine

calves. Her medical history revealed no further complications; no permanent medication was reported. Recent injuries, surgeries or trauma of the lower limbs were denied. Proposed liposuction of both calves as first-line therapy was refused by the patient. We therefore decided to initiate a treatment attempt of localized fat dissolving with intralesional application of PPC. The patient received subcutaneous injections of 5 ml PPC (Lipostabil , MCM Klosterfrau, Cologne, Germany), equivalent to one vial, into each calf. Injections were performed using a 27-gauge cannula, in a grid-like manner with 1 injection/cm 2 , and approximately 0.3 ml/ injection point. Injections were performed twice with an interval of 6 weeks between. Clinical inspection after the first injection cycle revealed mild reddening and swelling of the injection sites for approximately 3 days. No further side effects were reported. Two days after the second injection, however, the patient described a more painful injection site on the right calf compared to the first treatment. Moderate edema and reddening were visible. To exclude thrombosis, duplex sonography was performed without finding any pathology. Blood parameters were within normal ranges; D-dimer testing was negative. The patient was treated with ibuprofen 400 1–1–1 for 3 days. Pain and swelling were rapidly reduced after 2 days. However, 4 weeks later the patient presented with a palpable, mobile nodule in the dorsal region of the right calf which was painful on palpation during clinical examination. The overlying skin looked normal, the nodule was not clinically apparent. Ultrasound control revealed a round to oval structure (1.3 ! 2.0 cm) in the subcutaneous fat surrounded by echo-dense parts, corresponding to fibrosis. Puncturing of the nodule revealed a yellowish fluid, corresponding to liquid fat necrosis. Further treatments with PPC injections were rejected. We recommended the patient to observe the lesion and wait for possible spontaneous resolving. However, after 4 months the nodule had not disappeared and was therefore excised under local anesthesia. Histopathology revealed a thick fibrous capsule with amounts of necrotic fat tissue inside. In between the fibrous tissue some giant cells were present. The diagnosis of encapsulated fat necrosis was confirmed. Wound healing was without further complication. No recurrence occurred until today, 3 months after extirpation. Despite its broad usage, the precise action mechanism of Lipostabil still remains unclear [2, 3] . It seems that the injected substance leads to a localized necrosis of fat tissue with a subsequent inflammatory cascade and initiation of a repair process [3] . Chronological evaluation of human fat after lipolysis with PPC has revealed that after the induced destruction of fat cells a neutrophilic infiltrate developed in early stages, followed by lymphocytic infiltration, followed by macrophages/lipohages with possible pseudocysts, and fibrosis as late stage finding of a repair process [3] .