Australas Radio1 1992: 36: 255-256
Percutaneous Drainage of a Thigh Haematoma: Case Report of an Unusual Radiographic Appearance E.A. CARTER,M.B.,B.S. Registrar, Department of Radiology R.P. DAVIES, M.B.B.S.,F.R.A.C.R. Staff Specialist, Department of Radiology
R.B.DAVEY,M.B.B.S.,F.R.C.S.,F.R.A.C.S. Visiting Staff Specialist, Department of Paediatric Surgery Flinders Medical Centre,Bedford Park, SA 5042.
ABSTRACT We present a case of fat necrosis in the thigh of a ten year old girl, resulting in unusual multiple, ovoid filling defects seen in the residual cavity following drainage of a subcutaneous haematoma. No similar cases have been found on review of the literature. The appearance is described to aid diagnosis at the time of initial cavity drainage, avoiding the need for further investigation. CASE REPORT A ten year old girl presented with a four month history of an initially painful mass in the lateral aspect of her left thigh which developed over one week, at the site of a horse bite. Physical examination revealed an 8cm x 5cm diameter subcutaneous mass on the lateral aspect of the left thigh. It was raised 2cm above the skin surface but there was no overlying skin abrasion. She was afebrile and otherwise well. An ultrasound examination demonstrated a band of inhomogenous sonolucency with a few internal echoes, superficial to the vastus lateralis muscle. It had well defied margins and was compressible. A diagnosis of subcutaneous haematoma was made (Figure 1). It was decided to drain the collection percutaneously in view of its failure to resolve after four months. A needle was introduced under realtime ultrasound guidance and bloody material was aspirated. A 5F multiside-hole
Key words: Necrosis Fat Necrosis Haematoma Percutaneous Drainage Address for correspondence: Dr. R. Davies Department of Radiology Flinders Medical Centre Bedford Park SA 5042
Australasian Radiology, Vol. 36, No. 3 , August, 1992
FIGURE 1 - Axial 5MHz sector scan of the thigh of a ten year old girl, four months after a horse bite. A compressible sonolucent collection was demonstrated (mowed) superficial to the vastus lateralis muscle and femoral shaft. A diagnosis of post-traumatic haematoma was made.
catheter was then introduced over a guidewire and the cavity completely aspirated (total 25mls) with the palpable lump reducing in size by approximately half. Contrast was then instilled to delineate the extent of the cavity. A large number of ovoid filling defects were observed in the cavity, not clustered superiorly to suggest that these were air-bubbles, on the crosstable lateral view (Figure 2). Re-aspiration and further contrast injection failed to clear the cavity of these multiple ovoid objects.
A follow-up CT scan was performed six days later and demonstrated a biconvex soft tissue density in subcutaneous fat, just superficial to the vastus lateralis muscle, consistent with the residual cavity. Multiple ovoid filling defects were confirmed and these showed fat density (Figure 3).
Submitted for publication on: 13th August, 1991 Accepted for publication on: 10th September, 1991
255
E. A. CARTER eta/ mass in the left upper quadrant of a 39 year old male with a past history of abdominal trauma, while Marshak (4) reported a mesenteric mass of fat necrosis, simulating a carcinoma of the caecum on a barium enema. This was thought to be secondary to chronic appendicitis. Typically, the gross morphologic appearance of intraperitoneal fat necrosis, following acute pancreatitis, is that of scattered small foci of white opaque nodules (5,6). Rarely in acute pancreatitis peripheral fat necrosis results in skin nodules (7,6). It is also seen uncommonly following hypothermia, usually in neonates (8). The classic but uncommon radiological sign of fat necrosis in acute pancreatitis on plain abdominal films is faint mottled radiolucencies of fat density with interspersed water density mottling. The former is thought to be normal fat and the latter hydrolyzed of saponified fat (5). The findings in the case reported, are thought to be an unusual manifestation of fat necrosis secondary to a haematoma, with residual fatty tissue which did not become necrotic, remaining as the filling defects demonstrated. No similar reported case was found, and although filling defects from debris are often noted in abdominal sinograms and drainage tube checks, they are usually irregular with adjacent irregular walls and thus cause no diagnostic dilemma. Recognition of multiple rounded or ovid mobile filling defects in the appropriate clinical situation as manifestations of fat necrosis may avoid the need for a further investigation, as was performed in the present case.
FIGURE 2 - Cross-table lateral digital radiograph of the thigh mass following aspiration of 25ml of haemo-serous fluid and injection of contrast material into the cavity. A large number of ovoid filling defects were shown, not floating superiorly to suggest air bubbles.
REFERENCES FIGURE 3 - Follow-up CT scan performed six days after aspiration and compressive bandaging. The image is windowed to show ovoid fat density filling defects within the residual linear soft tissue density in subcutaneous fat overlying the vastus muscle. A diagnosis of fat necrosis was suggested.
DISCUSSION The appearances are thought to represent an unusual appearance of fat necrosis. Histological confirmation was not obtained but cytology of the aspirated fluid showed only mixed leukocytes and erythrocytes. No organisms were detected. The fatty nature of the ovoid densities was confirmed on the CT examination and post-traumatic necrosis was thought highly likely on the clinical history and examination. Necrosis is defined as the morphologic changes that follow cell death (1). Activated enzymes are released within and from dead cells and an inflammatory reaction is evoked with 256
further contribution from plasma and leukocytes. Not all traumatized tissue will become necrotic depending on the extent and type of injury. Furthermore, cell death does not always result in immediate cellular dissolution (1). There are three reports in the literature of focal areas of fat necrosis presenting as mass lesions. Haynes (2), reported an 8.0cm complex solid cystic, epigastric, intraperitoneal mass attached only to the falciform ligament and gallbladder serosa in a 40 year old male with chronic pancreatitis. It was demonstrated on both CT and ultrasound. Kordan (3) reported a similar 8.0cm complex cystic/solid mesenteric
1. Robbins SL, Cotran RS, Kumar V. Pathological basis of disease. Tokyo IgakuShoin/Saunders 1984 14-17. 2. Haynes JW,Brewer WH, Walsh J. Focal fat necrosis presenting as a palpable abdominal mass: CT evaluation. J Comput Assist Tomogr 1985; 9(3): 568-569. 3. Kordan B, Payne SD. Fat necrosis simulating a primary tumour of the mesentry: sonographic diagnosis. J Ultrasound in Med 1988; 7(6): 345-347. 4. Marshak RH, Lindner AE, Maklansky D, Goldberg M. Mesenteric fat necrosis simulating a carcinoma of the caecum. Am J Gastroenterol 1980; 74: 459-463. 5 . Berenson JE, Spitz HB, Felson B. The abdominal fat necrosis sign. Radiology 1971; 100: 567-571. 6. Lee PC, Howard JM. Fat necrosis. Surg Gynaecol Obstet 1979; 148: 785-789. 7. Berman B, Conteas C, Smith B, Leong S , Hornbeck L. Fatal pancreatitis presenting with subcutaneous fat necrosis. J Am Acad Dermatol 1987; 17(2): 359-364. 8. Silverman AK, Michels EH, Rasmussen IE. Subcutaneous fat necrosis in an infant, occuring after hypotherrnic cardiac surgery. J Am Acad Dermatol 1986; 15: 331-336.
Australasian Radiology, Vof.36, No. 3, August, I992
Percutaneous Drainage of a Thigh Haematoma: Case Report of an Unusual Radiographic Appearance E.A. CARTER,M.B.,B.S. Registrar, Department of Radiology R.P. DAVIES, M.B.B.S.,F.R.A.C.R. Staff Specialist, Department of Radiology
R.B.DAVEY,M.B.B.S.,F.R.C.S.,F.R.A.C.S. Visiting Staff Specialist, Department of Paediatric Surgery Flinders Medical Centre,Bedford Park, SA 5042.
ABSTRACT We present a case of fat necrosis in the thigh of a ten year old girl, resulting in unusual multiple, ovoid filling defects seen in the residual cavity following drainage of a subcutaneous haematoma. No similar cases have been found on review of the literature. The appearance is described to aid diagnosis at the time of initial cavity drainage, avoiding the need for further investigation. CASE REPORT A ten year old girl presented with a four month history of an initially painful mass in the lateral aspect of her left thigh which developed over one week, at the site of a horse bite. Physical examination revealed an 8cm x 5cm diameter subcutaneous mass on the lateral aspect of the left thigh. It was raised 2cm above the skin surface but there was no overlying skin abrasion. She was afebrile and otherwise well. An ultrasound examination demonstrated a band of inhomogenous sonolucency with a few internal echoes, superficial to the vastus lateralis muscle. It had well defied margins and was compressible. A diagnosis of subcutaneous haematoma was made (Figure 1). It was decided to drain the collection percutaneously in view of its failure to resolve after four months. A needle was introduced under realtime ultrasound guidance and bloody material was aspirated. A 5F multiside-hole
Key words: Necrosis Fat Necrosis Haematoma Percutaneous Drainage Address for correspondence: Dr. R. Davies Department of Radiology Flinders Medical Centre Bedford Park SA 5042
Australasian Radiology, Vol. 36, No. 3 , August, 1992
FIGURE 1 - Axial 5MHz sector scan of the thigh of a ten year old girl, four months after a horse bite. A compressible sonolucent collection was demonstrated (mowed) superficial to the vastus lateralis muscle and femoral shaft. A diagnosis of post-traumatic haematoma was made.
catheter was then introduced over a guidewire and the cavity completely aspirated (total 25mls) with the palpable lump reducing in size by approximately half. Contrast was then instilled to delineate the extent of the cavity. A large number of ovoid filling defects were observed in the cavity, not clustered superiorly to suggest that these were air-bubbles, on the crosstable lateral view (Figure 2). Re-aspiration and further contrast injection failed to clear the cavity of these multiple ovoid objects.
A follow-up CT scan was performed six days later and demonstrated a biconvex soft tissue density in subcutaneous fat, just superficial to the vastus lateralis muscle, consistent with the residual cavity. Multiple ovoid filling defects were confirmed and these showed fat density (Figure 3).
Submitted for publication on: 13th August, 1991 Accepted for publication on: 10th September, 1991
255
E. A. CARTER eta/ mass in the left upper quadrant of a 39 year old male with a past history of abdominal trauma, while Marshak (4) reported a mesenteric mass of fat necrosis, simulating a carcinoma of the caecum on a barium enema. This was thought to be secondary to chronic appendicitis. Typically, the gross morphologic appearance of intraperitoneal fat necrosis, following acute pancreatitis, is that of scattered small foci of white opaque nodules (5,6). Rarely in acute pancreatitis peripheral fat necrosis results in skin nodules (7,6). It is also seen uncommonly following hypothermia, usually in neonates (8). The classic but uncommon radiological sign of fat necrosis in acute pancreatitis on plain abdominal films is faint mottled radiolucencies of fat density with interspersed water density mottling. The former is thought to be normal fat and the latter hydrolyzed of saponified fat (5). The findings in the case reported, are thought to be an unusual manifestation of fat necrosis secondary to a haematoma, with residual fatty tissue which did not become necrotic, remaining as the filling defects demonstrated. No similar reported case was found, and although filling defects from debris are often noted in abdominal sinograms and drainage tube checks, they are usually irregular with adjacent irregular walls and thus cause no diagnostic dilemma. Recognition of multiple rounded or ovid mobile filling defects in the appropriate clinical situation as manifestations of fat necrosis may avoid the need for a further investigation, as was performed in the present case.
FIGURE 2 - Cross-table lateral digital radiograph of the thigh mass following aspiration of 25ml of haemo-serous fluid and injection of contrast material into the cavity. A large number of ovoid filling defects were shown, not floating superiorly to suggest air bubbles.
REFERENCES FIGURE 3 - Follow-up CT scan performed six days after aspiration and compressive bandaging. The image is windowed to show ovoid fat density filling defects within the residual linear soft tissue density in subcutaneous fat overlying the vastus muscle. A diagnosis of fat necrosis was suggested.
DISCUSSION The appearances are thought to represent an unusual appearance of fat necrosis. Histological confirmation was not obtained but cytology of the aspirated fluid showed only mixed leukocytes and erythrocytes. No organisms were detected. The fatty nature of the ovoid densities was confirmed on the CT examination and post-traumatic necrosis was thought highly likely on the clinical history and examination. Necrosis is defined as the morphologic changes that follow cell death (1). Activated enzymes are released within and from dead cells and an inflammatory reaction is evoked with 256
further contribution from plasma and leukocytes. Not all traumatized tissue will become necrotic depending on the extent and type of injury. Furthermore, cell death does not always result in immediate cellular dissolution (1). There are three reports in the literature of focal areas of fat necrosis presenting as mass lesions. Haynes (2), reported an 8.0cm complex solid cystic, epigastric, intraperitoneal mass attached only to the falciform ligament and gallbladder serosa in a 40 year old male with chronic pancreatitis. It was demonstrated on both CT and ultrasound. Kordan (3) reported a similar 8.0cm complex cystic/solid mesenteric
1. Robbins SL, Cotran RS, Kumar V. Pathological basis of disease. Tokyo IgakuShoin/Saunders 1984 14-17. 2. Haynes JW,Brewer WH, Walsh J. Focal fat necrosis presenting as a palpable abdominal mass: CT evaluation. J Comput Assist Tomogr 1985; 9(3): 568-569. 3. Kordan B, Payne SD. Fat necrosis simulating a primary tumour of the mesentry: sonographic diagnosis. J Ultrasound in Med 1988; 7(6): 345-347. 4. Marshak RH, Lindner AE, Maklansky D, Goldberg M. Mesenteric fat necrosis simulating a carcinoma of the caecum. Am J Gastroenterol 1980; 74: 459-463. 5 . Berenson JE, Spitz HB, Felson B. The abdominal fat necrosis sign. Radiology 1971; 100: 567-571. 6. Lee PC, Howard JM. Fat necrosis. Surg Gynaecol Obstet 1979; 148: 785-789. 7. Berman B, Conteas C, Smith B, Leong S , Hornbeck L. Fatal pancreatitis presenting with subcutaneous fat necrosis. J Am Acad Dermatol 1987; 17(2): 359-364. 8. Silverman AK, Michels EH, Rasmussen IE. Subcutaneous fat necrosis in an infant, occuring after hypotherrnic cardiac surgery. J Am Acad Dermatol 1986; 15: 331-336.
Australasian Radiology, Vof.36, No. 3, August, I992
