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DIII-468; No. of Pages 4
Diagnostic and Interventional Imaging (2014) xxx, xxx—xxx
E-QUID: ANSWER / Musculoskeletal imaging
Pelvic digit: A rare lesion夽 K. Bouzaïdi a,∗, A. Daghfous b, H. Chahbani a, M. Bouassida c, F. Jabnoun a, L. Rezgui Marhoul b a
Department of Radiology, MT Maamouri Hospital, 8000 Nabeul, Tunisia Department of Radiology, Trauma Center, Tunis, Tunisia c Department of Surgery, MT Maamouri Hospital, Nabeul, Tunisia b
Observation A 50-year-old man with a history of kidney cancer was referred to our department for evaluation of recurrent left lumbar and hypogastric pain after nephrectomy. On examination, there was no palpable mass. Biological tests were within normal limits. Plain radiograph of the pelvis (Fig. 1) and CT-scan (Fig. 2) were performed.
Figure 1.
Plain radiograph of the pelvis.
DOI of original article:http://dx.doi.org/10.1016/j.diii.2014.04.012. Here is the answer to the case ‘‘An incidental rare lesion’’ previously published. As a reminder we publish again the entire case with the response following. ∗ Corresponding author. E-mail address: khaled [email protected] (K. Bouzaïdi). 夽
http://dx.doi.org/10.1016/j.diii.2014.04.013 2211-5684/© 2014 Éditions franc ¸aises de radiologie. Published by Elsevier Masson SAS. All rights reserved.
Please cite this article in press as: Bouzaïdi K, et al. Pelvic digit: A rare lesion. Diagnostic and Interventional Imaging (2014), http://dx.doi.org/10.1016/j.diii.2014.04.013
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Figure 2.
Transverse (a) and sagittal (b) CT images of the pelvis.
What is your diagnosis? From the observation, what, from among the following, would your diagnosis be: • osteochondroma; • pelvic digit; • myositis ossificans; • Fong’s disease; • anterior superior iliac spine avulsion fracture.
Diagnosis Pelvic digit.
Results Plain radiograph of the pelvis shows the presence of a bony finger-like protuberance arising from the left iliac wing extending inferiorly and laterally, several centimeters in length (Fig. 3). CT-scan confirms the X-ray findings. It shows a bony structure with a clear corticomedullary differentiation, located anterior to the left iliac wing and extending inferiorly and laterally toward the abdominal wall. There is one pseudoarticulation at the site of origin in the pelvis (Fig. 4) and three pseudoarticulations in the body of the ossification (Fig. 5). This appearance is consistent with a pelvic digit.
Figure 3. Lateral detailed radiographic of the pelvis showing the finger-like bone articulating with the anterior superior angle of the left iliac wing and extending inferiorly and laterally toward the abdominal wall.
Discussion Pelvic digit is a rare anatomic anomaly in which bone develops in soft tissues adjacent to normal skeletal bone [1]. Its origin is still unknown. The suggested theory of origin
Please cite this article in press as: Bouzaïdi K, et al. Pelvic digit: A rare lesion. Diagnostic and Interventional Imaging (2014), http://dx.doi.org/10.1016/j.diii.2014.04.013
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Pelvic digit: A rare lesion
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Figure 4. Transverse (a), sagittal (b) and curved (c) CT images (bone window) showing the well corticated pelvic digit articulating with the left iliac wing and extending inferiorly.
is that the anomaly arises in the mesenchymal stage of bone growth within the first 6 weeks of embryogenesis [2]. Normally, the independent cartilaginous costal primordium of the first coccygeal vertebra fuses with the vertebral column. If the fusion does not take place, the cartilaginous centre may develop independently, forming a rudimentary ‘‘rib’’. Since the first case of pelvic digit described by Sullivan and Cornwell in 1974 [3], only few single cases and cases series have been reported. This rare congenital abnormal bone can arise at any level of the pelvic bones, and can even be located completely within the soft tissues of the abdominal wall [2,4]. Occasionally it is bilateral or multiple [5,6]. The condition is usually asymptomatic and is often discovered accidentally [7]. Occasionally, it can be a source of pain, disability or functional impairment by proximity to joint [1]. In these cases, surgical excision can be required. To our knowledge, there are only five reported cases of symptomatic pelvic digit [1,8]. In our case, the lumbar pain is probably not in relation with pelvic digit, which is fortuitous discovery. Typically, it has a rib or phalanx-like appearances with one or more joints or pseudo-joints within it, as in our case [6]. It often pseudoarticulates with the axial skeleton at its base. Computed tomography with three-dimensional CT-scan shows a bony structure with a clear cortex and medulla. It is the most valuable diagnostic tool because of its ability to facilitate accurate diagnosis, determine the exact number of bony segments and (pseudo-) articulations, make exact length measurements, and provide a more precise threedimensional localization. In addition, it allows clinicians
Figure 5. D volume rendering CT-scan showing the pelvic digit with four bony segments and three pseudoarticulations.
to evaluate the anatomical relationship of the pelvic digit with the neighboring soft tissue and articulations, which can explain clinical signs in symptomatic cases. It is also useful in equivocal cases making differential diagnosis, which should include other causes of heterotopic bone formation and bone tumors [2]. The absence of the cartilaginous
Please cite this article in press as: Bouzaïdi K, et al. Pelvic digit: A rare lesion. Diagnostic and Interventional Imaging (2014), http://dx.doi.org/10.1016/j.diii.2014.04.013
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ARTICLE IN PRESS
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cap distinguishes the pelvic digit from an osteochondroma. The well corticated appearance in the absence of trauma allows the differentiation from post-traumatic myositis ossificans, ligamentous calcification and avulsion injuries of the pelvis. Fong’s disease is characterized by iliac horns, usually bilateral, arising posteriorly and centrally from the ilia. It is important to recognize the benign entity of pelvic digit to avoid unnecessary additional clinical investigations or intervention. Plain radiographs and CT ease up to diagnosis this rare entity. Surgical removal is indicated only if symptoms such as limited range of motion or hip pain are disabling the patient.
Disclosure of interest The authors declare that they have no conflicts of interest concerning this article.
References [1] Evangelista P, Evangelista G. Dyspareunia associated with a pelvic digit. J Surg Case Rep 2011;12:7. [2] Van Breuseghem I. The pelvic digit: a harmless ‘‘eleventh’’ finger. Br J Radiol 2006;79:e106—7. [3] Sullivan D, Cornwell WS. Pelvic rib: report of a case. Radiology 1974;110:355—7. [4] Nguyen VD, Matthes JD, Wunderlich CC. The pelvic digit: CT correlation and review of the literature. Comput Med Imaging Graph 1990;14:127—31. [5] Rijal L, Nepal P. Multiple pelvic digits: a rare congenital anomaly. Eur J Orthop Surg Traumatol 2010;20:411—3. [6] McGlone BS, Hamilton S, FitzGerald MJ. Pelvic digit: an uncommon developmental anomaly. Eur Radiol 2000;10:89—91. [7] Granieri GF, Bacarini L. The pelvic digit: five new examples of an unusual anomaly. Skeletal Radiol 1996;25:723—6. [8] Moreta-Suarez J, Saez de Ugarte-Sobron O, Sanchez-Sobrino A, Martinez-De Los Mozos JL. The pelvic digit: a rare congenital anomaly as a cause of hip pain. J Orthop Case Rep 2012;2:19—22.
Please cite this article in press as: Bouzaïdi K, et al. Pelvic digit: A rare lesion. Diagnostic and Interventional Imaging (2014), http://dx.doi.org/10.1016/j.diii.2014.04.013
ARTICLE IN PRESS
DIII-468; No. of Pages 4
Diagnostic and Interventional Imaging (2014) xxx, xxx—xxx
E-QUID: ANSWER / Musculoskeletal imaging
Pelvic digit: A rare lesion夽 K. Bouzaïdi a,∗, A. Daghfous b, H. Chahbani a, M. Bouassida c, F. Jabnoun a, L. Rezgui Marhoul b a
Department of Radiology, MT Maamouri Hospital, 8000 Nabeul, Tunisia Department of Radiology, Trauma Center, Tunis, Tunisia c Department of Surgery, MT Maamouri Hospital, Nabeul, Tunisia b
Observation A 50-year-old man with a history of kidney cancer was referred to our department for evaluation of recurrent left lumbar and hypogastric pain after nephrectomy. On examination, there was no palpable mass. Biological tests were within normal limits. Plain radiograph of the pelvis (Fig. 1) and CT-scan (Fig. 2) were performed.
Figure 1.
Plain radiograph of the pelvis.
DOI of original article:http://dx.doi.org/10.1016/j.diii.2014.04.012. Here is the answer to the case ‘‘An incidental rare lesion’’ previously published. As a reminder we publish again the entire case with the response following. ∗ Corresponding author. E-mail address: khaled [email protected] (K. Bouzaïdi). 夽
http://dx.doi.org/10.1016/j.diii.2014.04.013 2211-5684/© 2014 Éditions franc ¸aises de radiologie. Published by Elsevier Masson SAS. All rights reserved.
Please cite this article in press as: Bouzaïdi K, et al. Pelvic digit: A rare lesion. Diagnostic and Interventional Imaging (2014), http://dx.doi.org/10.1016/j.diii.2014.04.013
+Model DIII-468; No. of Pages 4
ARTICLE IN PRESS
2
K. Bouzaïdi et al.
Figure 2.
Transverse (a) and sagittal (b) CT images of the pelvis.
What is your diagnosis? From the observation, what, from among the following, would your diagnosis be: • osteochondroma; • pelvic digit; • myositis ossificans; • Fong’s disease; • anterior superior iliac spine avulsion fracture.
Diagnosis Pelvic digit.
Results Plain radiograph of the pelvis shows the presence of a bony finger-like protuberance arising from the left iliac wing extending inferiorly and laterally, several centimeters in length (Fig. 3). CT-scan confirms the X-ray findings. It shows a bony structure with a clear corticomedullary differentiation, located anterior to the left iliac wing and extending inferiorly and laterally toward the abdominal wall. There is one pseudoarticulation at the site of origin in the pelvis (Fig. 4) and three pseudoarticulations in the body of the ossification (Fig. 5). This appearance is consistent with a pelvic digit.
Figure 3. Lateral detailed radiographic of the pelvis showing the finger-like bone articulating with the anterior superior angle of the left iliac wing and extending inferiorly and laterally toward the abdominal wall.
Discussion Pelvic digit is a rare anatomic anomaly in which bone develops in soft tissues adjacent to normal skeletal bone [1]. Its origin is still unknown. The suggested theory of origin
Please cite this article in press as: Bouzaïdi K, et al. Pelvic digit: A rare lesion. Diagnostic and Interventional Imaging (2014), http://dx.doi.org/10.1016/j.diii.2014.04.013
+Model DIII-468; No. of Pages 4
ARTICLE IN PRESS
Pelvic digit: A rare lesion
3
Figure 4. Transverse (a), sagittal (b) and curved (c) CT images (bone window) showing the well corticated pelvic digit articulating with the left iliac wing and extending inferiorly.
is that the anomaly arises in the mesenchymal stage of bone growth within the first 6 weeks of embryogenesis [2]. Normally, the independent cartilaginous costal primordium of the first coccygeal vertebra fuses with the vertebral column. If the fusion does not take place, the cartilaginous centre may develop independently, forming a rudimentary ‘‘rib’’. Since the first case of pelvic digit described by Sullivan and Cornwell in 1974 [3], only few single cases and cases series have been reported. This rare congenital abnormal bone can arise at any level of the pelvic bones, and can even be located completely within the soft tissues of the abdominal wall [2,4]. Occasionally it is bilateral or multiple [5,6]. The condition is usually asymptomatic and is often discovered accidentally [7]. Occasionally, it can be a source of pain, disability or functional impairment by proximity to joint [1]. In these cases, surgical excision can be required. To our knowledge, there are only five reported cases of symptomatic pelvic digit [1,8]. In our case, the lumbar pain is probably not in relation with pelvic digit, which is fortuitous discovery. Typically, it has a rib or phalanx-like appearances with one or more joints or pseudo-joints within it, as in our case [6]. It often pseudoarticulates with the axial skeleton at its base. Computed tomography with three-dimensional CT-scan shows a bony structure with a clear cortex and medulla. It is the most valuable diagnostic tool because of its ability to facilitate accurate diagnosis, determine the exact number of bony segments and (pseudo-) articulations, make exact length measurements, and provide a more precise threedimensional localization. In addition, it allows clinicians
Figure 5. D volume rendering CT-scan showing the pelvic digit with four bony segments and three pseudoarticulations.
to evaluate the anatomical relationship of the pelvic digit with the neighboring soft tissue and articulations, which can explain clinical signs in symptomatic cases. It is also useful in equivocal cases making differential diagnosis, which should include other causes of heterotopic bone formation and bone tumors [2]. The absence of the cartilaginous
Please cite this article in press as: Bouzaïdi K, et al. Pelvic digit: A rare lesion. Diagnostic and Interventional Imaging (2014), http://dx.doi.org/10.1016/j.diii.2014.04.013
+Model DIII-468; No. of Pages 4
ARTICLE IN PRESS
4
K. Bouzaïdi et al.
cap distinguishes the pelvic digit from an osteochondroma. The well corticated appearance in the absence of trauma allows the differentiation from post-traumatic myositis ossificans, ligamentous calcification and avulsion injuries of the pelvis. Fong’s disease is characterized by iliac horns, usually bilateral, arising posteriorly and centrally from the ilia. It is important to recognize the benign entity of pelvic digit to avoid unnecessary additional clinical investigations or intervention. Plain radiographs and CT ease up to diagnosis this rare entity. Surgical removal is indicated only if symptoms such as limited range of motion or hip pain are disabling the patient.
Disclosure of interest The authors declare that they have no conflicts of interest concerning this article.
References [1] Evangelista P, Evangelista G. Dyspareunia associated with a pelvic digit. J Surg Case Rep 2011;12:7. [2] Van Breuseghem I. The pelvic digit: a harmless ‘‘eleventh’’ finger. Br J Radiol 2006;79:e106—7. [3] Sullivan D, Cornwell WS. Pelvic rib: report of a case. Radiology 1974;110:355—7. [4] Nguyen VD, Matthes JD, Wunderlich CC. The pelvic digit: CT correlation and review of the literature. Comput Med Imaging Graph 1990;14:127—31. [5] Rijal L, Nepal P. Multiple pelvic digits: a rare congenital anomaly. Eur J Orthop Surg Traumatol 2010;20:411—3. [6] McGlone BS, Hamilton S, FitzGerald MJ. Pelvic digit: an uncommon developmental anomaly. Eur Radiol 2000;10:89—91. [7] Granieri GF, Bacarini L. The pelvic digit: five new examples of an unusual anomaly. Skeletal Radiol 1996;25:723—6. [8] Moreta-Suarez J, Saez de Ugarte-Sobron O, Sanchez-Sobrino A, Martinez-De Los Mozos JL. The pelvic digit: a rare congenital anomaly as a cause of hip pain. J Orthop Case Rep 2012;2:19—22.
Please cite this article in press as: Bouzaïdi K, et al. Pelvic digit: A rare lesion. Diagnostic and Interventional Imaging (2014), http://dx.doi.org/10.1016/j.diii.2014.04.013
![[The pelvic digit: a rare bone abnormality].](/assets/img/hold.png)
