DOI:10.2214/AJR.05.0688
AJR 2006; 187:1338-1341
© American Roentgen Ray Society
Decubital Ischemic Fasciitis: Clinical, Pathologic, and MRI Features of Pseudosarcoma
Hakan Ilaslan1,
Michael Joyce2,
Thomas Bauer3 and
Murali Sundaram1
1 Department of Radiology, Cleveland Clinic, 9500 Euclid Ave. A21, Cleveland, OH
44195.
2 Department of Orthopedic Surgery, Cleveland Clinic, Cleveland, OH.
3 Department of Pathology and Orthopedic Surgery, Cleveland Clinic, Cleveland,
OH.
Received April 21, 2005;
accepted after revision June 7, 2005.
Address correspondence to H. Ilaslan
(ilaslah{at}ccf.org).
Abstract
OBJECTIVE. The purpose of this report is to describe clinical,
pathologic, and MRI findings on decubital ischemic fasciitis, which is a rare
soft-tissue tumor sarcoma simulator.
CONCLUSION. Decubital ischemic fasciitis is a reactive,
nonneoplastic lesion typically seen in older debilitated patients at pressure
points. Because this lesion simulates soft-tissue sarcoma, both clinically and
histologically, it is important to recognize the MRI features and limit
misdiagnosis of sarcoma.
Keywords: decubital ischemic fasciitis • hip • MRI • pseudosarcoma • sarcoma • soft-tissue tumor
Introduction
Decubital ischemic fasciitis was first described as "atypical
decubital fibroplasia" in 1992 by Montgomery et al.
[1] who found distinctive
pseudosarcomatous fibroblastic proliferations in 28 patients, most of whom
were physically debilitated and immobilized. Perosio and Weiss
[2] reported similar lesions
under the name "ischemic fasciitis" in six patients. Since its
initial description, a few case reports
[3-6]
and a series of three patients
[7] have been published
exclusively in the pathology literature. We believe the term decubital
ischemic fasciitis comprehensively describes this entity and incorporates the
best of previously used titles. To our knowledge, this subject has not been
reported in the imaging literature. Because decubital ischemic fasciitis may
simulate soft-tissue sarcoma both clinically and histologically, it is
important to recognize this entity to prevent unnecessary interventions or
overtreatment. We discuss three patients who underwent MRI; in one of these,
the diagnosis was made prospectively.
Materials and Methods
After obtaining approval from our institutional review board, we performed
a retrospective computer search of our pathology database for the years 1992
through 2004 to identify patients who fit the description for decubitus
ischemic fasciitis.
Medical records were reviewed to determine patient age, sex, location of
the lesion, clinical findings at presentation, risk factors, and clinical
outcome. Two experienced musculoskeletal radiologists interpreted the MRIs by
consensus. Pathology specimens were reviewed by an experienced musculoskeletal
pathologist. Patients with known decubitus ulcers were excluded from the
study.
Results
Five patients, three women and two men, were diagnosed with decubital
ischemic fasciitis around the hip from 1992 through 2004. These patients
ranged in age from 53 to 91 years (mean age, 68 years). The lesions were right
sided in three and left sided in two patients. MRI was available in three of
these patients, who are the focus of this report. In each of these three
patients, MRI showed a round masslike area—measuring approximately 2 cm,
3.5 cm, and 4.5 cm—in the subcutaneous tissue centered around the
proximal iliotibial band at the level of the greater trochanter. On
T1-weighted images, the masses were isointense to muscle (Figs.
1A and
2A). On T2-weighted images, a
slight heterogeneous hyperintense signal was seen
(Fig. 1B). Marked enhancement
was seen in each lesion with gadolinium, but small areas of nonenhancement
occurred centrally that corresponded to macroscopic areas of ischemia and
necrosis (Figs. 2A and
2B). Variable amounts of
edemalike signals were present around the lesions, which were best seen on
T2-weighted (Fig. 2B) and STIR
(Fig. 1C) sequences. The
overlying skin and superficial subcutaneous tissues were intact without visual
abnormality of the skin other than bulging. A necrotic neoplasm or abscess was
considered in the radiologic differential of the first two patients when
prospectively seen. Diagnosis of ischemic fasciitis was suspected in the third
patient after the initial experience of the authors. Clinically, each patient
presented with a palpable mass over the hip area, and a soft-tissue sarcoma
was suspected. Clinical and laboratory findings did not suggest infection.
History of prolonged immobilization was present in all patients. Three
patients had paraplegia, one had long-standing multiple sclerosis, and one had
oxygen-dependent emphysema and severe osteoarthritis of the knees. All
required wheelchair use for mobilization.
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Fig. 1A —64-year-old man, who is wheelchair-bound with long-term
multiple sclerosis, with right hip mass. MR images show approximately 4.5-cm
subcutaneous tissue mass crossing iliotibial band (black arrows)
abutting greater trochanter. On axial T1-weighted image (A) (TR/TE,
550/12), mass is isointense to muscle. On axial T2-weighted image (B)
(5,070/84), mass shows nonspecific signal features with few small foci of
fluidlike hyperintensities; edemalike signal is present, extending along
iliotibial band anteriorly (white arrow).
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Fig. 2A —91-year-old woman, who resides in nursing home, with right
hip mass. MR images show large subcutaneous mass with nonspecific imaging
features that traverse iliotibial band on T1-weighted (A) (TR/TE,
590/11) and T2-weighted (B) (4,000/60) fat-suppressed images on axial
plane. Gadolinium-enhanced axial T1-weighted fat suppressed images (C)
(600/12) show thick, nodular peripheral enhancement of mass (white
arrows) with central hypointense area of nonenhancement consistent with
necrosis. Note necrotic focus straddling iliotibial band (black arrow
in B).
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Fig. 1B —64-year-old man, who is wheelchair-bound with long-term
multiple sclerosis, with right hip mass. MR images show approximately 4.5-cm
subcutaneous tissue mass crossing iliotibial band (black arrows)
abutting greater trochanter. On axial T1-weighted image (A) (TR/TE,
550/12), mass is isointense to muscle. On axial T2-weighted image (B)
(5,070/84), mass shows nonspecific signal features with few small foci of
fluidlike hyperintensities; edemalike signal is present, extending along
iliotibial band anteriorly (white arrow).
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Fig. 2B —91-year-old woman, who resides in nursing home, with right
hip mass. MR images show large subcutaneous mass with nonspecific imaging
features that traverse iliotibial band on T1-weighted (A) (TR/TE,
590/11) and T2-weighted (B) (4,000/60) fat-suppressed images on axial
plane. Gadolinium-enhanced axial T1-weighted fat suppressed images (C)
(600/12) show thick, nodular peripheral enhancement of mass (white
arrows) with central hypointense area of nonenhancement consistent with
necrosis. Note necrotic focus straddling iliotibial band (black arrow
in B).
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Fig. 1C —64-year-old man, who is wheelchair-bound with long-term
multiple sclerosis, with right hip mass. Coronal STIR (5,020/112; inversion
time 130 ms) also shows edemalike signal (arrows) surrounding
lesion.
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A needle or limited incisional biopsy was performed under local anesthesia
in all five patients. Histologically the biopsy materials showed areas of
partially necrotic fibrous tissue with interspersed, enlarged, spindle-shaped
cells (Fig. 3A) and myxoid
degeneration of muscle and connective tissue. Some of the enlarged
spindle-shaped cells had prominent nuclei and nucleoli, similar to the cells
seen in proliferative fasciitis or proliferative myositis
(Fig. 3B).
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Fig. 3B —91-year-old woman with decubital ischemic fasciitis. Higher
magnification of different portion of mass. Spindle-shaped cells with large
nuclei and conspicuous nucleoli have appearance reminiscent of nuclei of
autonomic ganglion cells; this appearance is also seen in some sarcomas and in
proliferative myositis. Although occasional mitotic features were present (not
seen in this photograph), these lesions do not have atypical mitoses. (H and
E, x 1,000)
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Two of the patients elected to have these lesions resected. No local
recurrence developed since the surgery at 5 months and 7 months follow-up. One
patient elected not to have surgical intervention; at 1-year follow-up after
the biopsy, the palpable mass was unchanged in size with minimal symptoms.
Discussion
Atypical decubital fibroplasia
[1] and ischemic fasciitis
[2] are terms that were
independently introduced to describe virtually identical clinicopathologic
entities that had not been described previously. These two studies were
published within 12 months of each other and included a combined total of 34
cases. They describe a lesion in the deep subcutaneous tissue at pressure
points or bone prominences encountered in patients who were debilitated,
confined to bed, or wheelchair bound, and who were usually elderly. The terms
atypical decubital fibroplasia and ischemic fasciitis have been used
interchangeably by successive authors since the initial description of the
lesion. Both terms have merit because they both signify the underlying
presumed pathophysiologic process and the histopathologic changes
[1,
2]. We chose to denote these
masses as decubital ischemic fasciitis, combining the two existing terms,
hoping that this name will serve to recall both the presumed underlying cause
and the central pathologic features of this unusual reactive lesion.
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Fig. 2C —91-year-old woman, who resides in nursing home, with right
hip mass. MR images show large subcutaneous mass with nonspecific imaging
features that traverse iliotibial band on T1-weighted (A) (TR/TE,
590/11) and T2-weighted (B) (4,000/60) fat-suppressed images on axial
plane. Gadolinium-enhanced axial T1-weighted fat suppressed images (C)
(600/12) show thick, nodular peripheral enhancement of mass (white
arrows) with central hypointense area of nonenhancement consistent with
necrosis. Note necrotic focus straddling iliotibial band (black arrow
in B).
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Based on literature reports
[1-7],
this lesion has shown increased mitoses and large basophilic cells in more
than 50% of patients, resulting in a reactive lesion with an appearance that
is often misinterpreted as a sarcoma, especially in the clinical setting of a
soft-tissue mass in an elderly patient. The microscopic appearance, however,
is similar to the reactive tissue found in the base of a decubitus ulcer, even
though the dermis overlying a decubital ischemic fasciitis lesion is intact.
We have not found any experimental studies that elaborate on an ischemic
pathogenesis by describing the evolving deep tissue changes produced by
intermittent tissue compression that results in an intact dermis and a deep
spindle-cell lesion similar to those seen in our patients and in those
previously reported.
The MRI features in all three of our patients confirmed the clinical
impression of a mass. Features common to all three patients' masses were
isointense signal intensities compared with muscle on T1-weighted sequences
(Figs. 1A and
2A); heterogeneously
hyperintense signal intensities on T2-weighted images (Figs.
1B and
2B); breaching of fascia; and
intense enhancement after administration of gadolinium, but with areas that
did not enhance in the center, indicating necrotic foci
(Fig. 2C). These features are
nonspecific and common to many necrotic sarcomas and abscesses. Somewhat
distinctive in these patients, however, was the location of the masses at a
pressure point (the greater trochanter), in the subcutaneous tissues, crossing
the iliotibial band, and abutting but not invading the greater trochanter. All
three masses had some degree of associated edemalike signal around them. The
imaging features in a wheelchair-bound patient enabled an accurate prebiopsy
diagnosis in that patient (Figs.
1A,
1B, and
1C).
Our report focuses on lesions that presented near the greater trochanter.
Other locations in which this lesion has been described include the shoulder,
sacral area, posterior chest wall, and most recently, vulvovagina
[8]. Although the greater
trochanter would not conventionally be considered a pressure point for a
decubital reaction in persons lying supine or prone, it could be in patients
lying on their sides or in wheelchair-bound patients such as in this
series.
The three patients in our study do not provide enough data to reach many
conclusions regarding MRI features and microscopic appearances. To the
radiologists involved in this study, the presumed areas of necrosis in all
three patients were of interest. These areas would appear to correspond to
liquefactive coagulative necrosis histologically described and believed to be
secondary to ischemia [2]. The
extent of necrosis is variable as shown by MRI and corresponding
histology.
Because these patients are debilitated and considered poor operative and
anesthetic risks, an accurate diagnosis clearly saves them further unnecessary
morbidity. One of our patients is being clinically followed after a
percutaneous biopsy. As with all musculoskeletal lesions, close communication
between radiologist, surgeon, and pathologist is important. Consideration of
decubital ischemic fasciitis in the appropriate setting by the radiologist
helps the pathologist in considering this entity and avoid mistaking a
reactive lesion for a sarcoma. Most musculoskeletal neoplasms that require
biopsy are currently investigated by percutaneous biopsy, and because
fine-needle aspiration findings appear to be frequently interpreted as
"suspicious" or "suggestive" of malignancy
[6], awareness of this entity
in a debilitated patient group makes an accurate diagnosis and avoidance of
overtreatment of paramount importance.
Between 1992 (when atypical decubital fibroplasia was first described) and
1998, a review of the pathology files of Massachusetts General Hospital
[7] revealed three cases. At
our institution between 1992 and 2004, we encountered five cases. Considering
the large number of long-term care and chronically disabled patients, the
relative rarity of the lesion is difficult to explain. Because MRI remains the
examination of choice for soft-tissue masses and MRI is widely used and
interpreted in the community, all radiologists interpreting musculoskeletal MR
examinations should be familiar with the constellation of clinical features,
favored locations, and MRI findings of decubital ischemic fasciitis to
appropriately introduce it in their differential diagnosis.
References
- Montgomery EA, Meis JM, Mitchell MS, Enzinger FM. Atypical
decubital fibroplasia. A distinctive fibroblastic pseudotumor occurring in
debilitated patients. Am J Surg Pathol1992; 16:708
-715[Medline]
- Perosio PM, Weiss SW. Ischemic fasciitis: a juxta-skeletal
fibroblastic proliferation with a predilection for elderly patients.
Mod Pathol 1993;6
: 69-72[Medline]
- Kendall BS, Liang CY, Lancaster KJ, et al. Ischemic fasciitis:
report of a case with fine needle aspiration findings. Acta
Cytol 1997; 41:598
-602[Medline]
- Fukunaga M. Atypical decubital fibroplasia with unusual histology.
APMIS 2001; 109:631
-635[CrossRef][Medline]
- Ishida YM, Machinami R. Atypical decubital fibroplasia in a young
patient with melorheostosis. Pathol Int1998; 48:160
-163[Medline]
- Washing D, Zaher A. Pathologic quiz case: a 76-year-old debilitated
woman with a right thigh mass—ischemic fasciitis (atypical decubital
fibroplasia). Arch Pathol Lab Med 2004;128
: e139-e140[Medline]
- Baldassano MF, Rosenberg AE, Flotte TJ. Atypical decubital
fibroplasia: a series of three cases. J Cutan Pathol1998; 25:149
-152[Medline]
- Scanlon R, Kelehan P, Flannelly G, McDonald D, McCluggage WG.
Ischemic fasciitis: an unusual vulvovaginal spindle cell lesion.
Int J Gynecol Pathol 2004;23
: 65-67[Medline]
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Abstract
Introduction
