British Journal of Radiology (2003) 76, 264-267
© 2003 British Institute of Radiology
doi: 10.1259/bjr/31110098
Paraffinoma in anterior abdominal wall mimicking liposarcoma
K T Wong, MBChB, FRCR1,
P S F Lee, MBBS, FRCR1,
Y L Chan, MBBS, FRCR1 and
L T C Chow, MD, FRCPath, FRCPA2
1 Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, Shatin and 2 Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, Shatin, Hong Kong
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Abstract
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Paraffinoma of breast is a recognized complication of paraffin injection for breast augmentation. Liquid paraffin can extend along fascial planes to involve adjacent tissues. A rare case of paraffinoma in anterior abdominal wall, which was misdiagnosed as a soft tissue liposarcoma before surgical excision, is reported. It was heterogeneous with marked posterior acoustic shadowing and small peripheral cysts on ultrasound. On MRI, it had ill-defined margins and was heterogeneous in signal intensity. Small round components which were hypointense on all sequences were demonstrated. There is significant overlapping of imaging features between paraffinoma and soft tissue liposarcoma. Histological differentiation from well-differentiated liposarcoma may also be difficult. A detailed clinical history of previous paraffin injection for breast augmentation is very important for correct interpretation of imaging and histopathological findings.
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Introduction
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Paraffinoma is a recognized long-term complication of previous paraffin injection for breast augmentation. It occurs most commonly within the breast that has been augmented. We report a rare case of paraffinoma in the anterior abdominal wall arising through extension along fascial planes and describe the ultrasound and MRI features. The imaging and histological findings simulated an abdominal wall liposarcoma. This emphasizes the importance of a detailed clinical history of previous paraffin injection in achieving a correct diagnosis.
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Case report
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A 28-year-old woman presented with a painless hard mass over the right upper quadrant of the abdomen of 1 month's duration. She denied any history of trauma or surgery. Physical examination revealed a large firm non-tender mass arising from the anterior abdominal wall in the right upper quadrant.
Ultrasound examination with linear array high-frequency transducer (10 MHz) (Elegra Sonoline, Siemens Medical Systems, Erlangen, Germany) demonstrated a large heterogeneous area in the subcutaneous tissue of the right abdominal wall casting marked posterior acoustic shadowing (Figure 1
). Multiple small anechoic cysts were noted at the periphery of the lesion. The ultrasound findings were non-specific and the depth of lesion could not be properly assessed.
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Figure 1. Transverse extended field-of-view high-frequency ultrasound image showing heterogeneous echoes in subcutaneous layer of right anterior abdominal wall casting marked posterior acoustic shadowing. The deep extent of the lesion and underlying abdominal wall muscle cannot be properly assessed. Small anechoic cysts (arrows) are present in its periphery.
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Ultrasound-guided core biopsy of the lesion using 18-gauge Temno biopsy needle (Allegiance Healthcare Corporation, McGaw Park, USA) was performed under local anaesthesia. The first biopsy showed adipose tissue only. The patient noted a subjective increase in size of the mass after the biopsy. A second biopsy was performed. Microscopic examination of the second biopsy specimen revealed lobules of fat cells of irregular sizes separated by fine fibrovascular septa. There were areas of lymphocytic infiltration and multinucleated giant cells with ingested fat vacuoles in cytoplasm. Some of these fat cells showed mild nuclear pleomorphism and hyperchromatism. The histological diagnosis was an atypical lipomatous lesion; liposarcoma was one of the differential diagnoses.
MRI examination was performed with 1.5 Tesla MR system (Gyroscan ACS, Philips Medical System, Best, Netherlands). It showed an extensive soft tissue mass in the subcutaneous layer of the right anterior abdominal wall. The mass had an ill-defined margin and was heterogeneous in signal intensity on T1 weighted (recovery time (TR): 618 ms, echo time (TE): 12 ms, field of view (FOV): 350, slice thickness: 10 mm, number of acquisition: 4, matrix: 205 x 256) and fat-suppressed T2 weighted images (TR: 1800 ms, TE: 60 ms, FOV: 350, slice thickness: 10 mm, number of acquisition: 4, matrix: 165 x 256) (Figure 2). Areas of fat signal intensity were demonstrated within the lesion, which were better seen on T1 weighted images. In addition, there were small round foci of abnormal signal intensity in the periphery which were hypointense on both T1 weighted and fat-suppressed T2 weighted images. The adjacent right external oblique muscle showed high signal change on fat-suppressed T2 weighted images which was suspicious of possible tumour involvement. No intraperitoneal abnormalities were detected.
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Figure 2. (a) T1 weighted axial MR image of abdomen showing heterogeneous signal with ill-defined margin in subcutaneous fat of right anterior abdominal wall. It is of predominantly intermediate signal intensity and isointense to adjacent muscle. Areas of signal intensity identical to subcutaneous fat were demonstrated (arrow). Small round hypointense foci are also detected in the periphery part of the lesion (open arrows). (b) Fat-suppressed T2 weighted axial MR images of abdomen showing heterogeneous predominantly low signal intensity in subcutaneous layer of right anterior abdominal wall. High signal changes are present in right external oblique muscle (arrow) which are contiguous with the overlying subcutaneous lesion. Small round peripheral markedly hypointense foci are also demonstrated (open arrows) corresponding to the findings on T1 weighted image.
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A provisional diagnosis of liposarcoma was made and surgical exploration was advised. Subsequent surgical excision with mesh and skin flap repair was performed. Multiple smaller but similar lesions in the anterior abdominal wall close to the main lesion were found intraoperatively. The excised specimen consisted of a large piece of skin and underlying subcutaneous fat and skeletal muscle. Within the subcutaneous tissue was a fatty lesion that had a well-defined deep margin in the fascia overlying the skeletal muscle. Cut surface of the lesion showed lobulated fatty material, in which were evenly scattered small nodules (2–5 mm) that showed a nearly transparent oily cut surface (Figure 3a). Histologically, the striking feature was the presence of vacuolated spaces of varying sizes with surrounding multinucleated giant cells, scattered throughout the background of fat cells and foamy histiocytes (Figure 3b). There were also many vacuolated cells with appearances akin to that of lipoblasts. There was no features of malignancy and the underlying muscles were not involved. The histologic features were suggestive of an oleogranulomatous reaction to exogenous material.
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Figure 3. (a) Cut surface of the excised specimen shows lobulated fatty material with evenly scattered small nodules that show a nearly transparent oily cut surface. (b) Histology of the lesion consists of vacuolated spaces of varying sizes, with surrounding multinucleated giant cells, that scatter throughout a background of fat cells and foamy histiocytes. Lipoblasts-like cells are also seen.
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Owing to the atypical radiological and histological results, the patient was interviewed again with particular emphasis on previous surgical history. The patient then admitted to having had "liquid" injections into both breasts for cosmetic purposes several years before. A subcutaneous abdominal wall paraffinoma simulating liposarcoma secondary to previous paraffin breast augmentation was the final diagnosis.
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Discussion
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There are numerous techniques for breast augmentation. Liquefied paraffin wax or beewax injection was widely practiced up to the 1970s in Asian countries, particularly by back street practitioners. This method is no longer performed owing to the serious local complications of formation of paraffinoma, inflammatory reactions, tissue necrosis and sinus tract formation. Systemic complications including pulmonary and cerebral embolism have been reported [1].
Paraffinoma of the breast is a well-recognized long-term complication of paraffin injection. Clinically, it may present as a spectrum from a painless breast mass to a destructive ulcer simulating breast carcinoma [2]. Dense fibrosis in the retroglandular region of the breast causing streaky opacities and bizarre architectural distortion are the characteristic findings on conventional mammography. Flocculent, amorphous, ring or rounded calcifications may also be present within the breast and axilla [3].
Paraffin remains in liquid form within the injected tissues. Extension along fascial planes into the chest wall, supraclavicular fossa and anterior abdominal wall has been reported [3, 4]. Plain radiographs show extensive flocculent and conglomerate soft tissue calcifications in affected areas. To the best of our knowledge, this is the first reported case describing the ultrasound and MRI features of paraffinoma of the anterior abdominal wall arising via extension along fascial planes.
MRI features of paraffinoma of breast have been reported [5]. Khong et al found all 11 breast paraffinomas had similar MRI appearances, comprising a "main" component and a "round" component. The main component was plaque-like and had an irregular outline that gave it an infiltrative appearance. The signal intensity was low to intermediate on both T1-weighted and T2-weighted sequences. The round component was nodular and varied in size (from 2 mm to 2 cm) and number (from 5 to 30). The signal intensity of the round component was characteristic, which was low on both T1-weighted and T2-weighted sequences and was markedly suppressed on fat-suppression sequences (even hypointense to subcutaneous fat). Retrospective review of MR images in this patient showed similar findings, with the major part being composed of main component, and minor round component in the periphery. However, in the absence of clinical history of previous paraffin injection, suspicious histological findings on core biopsy specimen and infiltrative nature of the lesion on MRI, malignant soft tissue tumour (especially liposarcoma) cannot be confidently excluded.
The major diagnostic difficulty in this case is to differentiate paraffinoma in subcutaneous fatty tissue from liposarcoma. Liposarcoma is the second most common soft tissue sarcoma, accounting for 16–18% of all such lesions [6]. It is classified into four histological subtypes: well-differentiated; myxoid; round cell; and pleomorphic, which affect both patient prognosis and surgical planning. The imaging appearances are well-known to be variable, depending on the proportion of soft tissue to fatty component and the histological subtypes [7, 8]. Apart from well-differentiated subtype, moderate or marked heterogeneity of signal intensity is a commonly encountered feature on MRI. It may contain little or no fat within the lesion, which occur in more than 50% of myxoid subtype and the majority of cases in pleomorphic and round-cell subtypes [8]. There is much overlapping of MRI features between abdominal wall paraffinoma and liposarcoma, thus it is difficult to differentiate the two conditions by imaging alone. Perhaps the only distinctive imaging feature is the presence of round component with characteristic signal intensity on MRI, which is not present in liposarcoma. The MRI finding of round components, probably correspond to previous histopathology reports of paraffinoma with paraffin-containing cystic spaces [5, 9]. It also explains the appearances of small peripheral cystic areas on ultrasound. The importance of a full clinical history in the correct interpretation of radiological examination has to be emphasized. Without the clinical history of previous paraffin injection into the breasts, a definite diagnosis could not be made with confidence. Unfortunately, some patients, for reasons of privacy, are reluctant to volunteer a history of breast augmentation, as illustrated in this case.
Some features in this case, such as anatomical distribution and age of the patient, are not typical for liposarcoma. A review of a large series of soft tissue tumours shows that liposarcoma most commonly occurs in men in the fifth to sixth decades. The retroperitoneum and lower extremity are the most common sites of involvement [10]. If a suspected case of liposarcoma is encountered in an atypical location and in an atypical age group, extra caution should be exercised before making the diagnosis. Alternative diagnoses should be considered with a thorough review of the clinical details.
The histological findings in paraffinoma are often not straightforward and may not totally exclude a malignant lesion. Liquid paraffin infiltrates soft tissues and causes a foreign body reaction characterized histologically by chronic granulomatous inflammation with infiltration by lymphocytes, plasma cells, lipid-containing foamy cells and cystic spaces containing paraffin oil and calcification [9]. The presence of numerous vacuolated spaces with surrounding foreign body multinucleated giant cell reaction is suggestive of reaction to an exogenous cause. However, histologically it may be difficult to distinguish between a subcutaneous paraffinoma and well-differentiated liposarcoma. Hence the importance of obtaining a relevant clinical history in interpreting histopathological results has to be emphasized.
In summary, we report a rare case of paraffinoma in the anterior abdominal wall mimicking liposarcoma. Imaging features on ultrasound and MRI are described. The limitations of radiological and histological examination in making a diagnosis of paraffinoma in an unusual site without a relevant clinical history is illustrated. The importance of obtaining detailed clinical information has to be stressed, because paraffinomas may develop at unusual sites via extension along fascial planes.
Received for publication March 20, 2002.
Accepted for publication September 23, 2002.
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References
|
|---|
- Steinbach BG, Hardt NS, Abbitt PL, Landa L, Caffee HH. Breast implants, common complications and concurrent breast disease. Radiographics 1993;13:95–118.[Abstract]
- Ho WS, Chan AC, Law KB. Management of paraffinoma of the breast: 10 years' experience. Br J Plast Surg 2001;54:232–4.[Medline]
- Yang WT, Suen M, Ho WS, Metreweli C. Paraffinomas of the breast: mammographic, ultrasonographic and radiographic appearances with clinical and histopathological correlation. Clin Radiol 1996;51:130–3.[CrossRef][Medline]
- Ooi GC, Peh WCG, Ip M. Migration and lymphatic spread of calcified paraffinoma of breast augmentation. Australas Radiol 1996;40:404–7.[Medline]
- Khong PL, Ho LWC, Chan JHM, Leong LLY. MR imaging of breast paraffinomas. AJR 1999;173:929–32.[Abstract/Free Full Text]
- Enzinger FM, Weiss SW. Soft tissue tumours. 2nd Edn. St Louis, MO: Mosby-Year Book, 1998;346–82.
- Jelinek JS, Kransdorf MJ, Shmookler BM, Aboulafia AJ, Malawer MM. Liposarcoma of the extremities: MR and CT findings in the histologic subtypes. Radiology 1993;186:455–9.[Abstract/Free Full Text]
- Munk PL, Lee MJ, Janzen DL, et al. Lipoma and liposarcoma: Evaluation using CT and MR imaging. Am J Roentgenol 1997;169:589–94.[Free Full Text]
- Alagaratnam TT, Ng WF. Paraffinomas of the breast: an oriental curiosity. Aust N Z J Surg 1996;66:138–40.[Medline]
- Kransdorf MJ. Malignant soft-tissue tumors in a large referral population: distribution of diagnoses by age, sex and location. AJR 1995;164:129–34.[Abstract/Free Full Text]
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Abstract
Introduction
