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Frontal parosteal lipoma with thickening of diploic space
JPRAS Open 5 (2015) 19e23
Contents lists available at ScienceDirect
JPRAS Open journal homepage: http://www.journals.elsevier.com/ jpras-open
Case report
Frontal parosteal lipoma with thickening of diploic space Tsuyoshi Morishita a, Kazuhiro Toriyama b, *, Shunjiro Yagi c, Keisuke Takanari b, Masazumi Fujii d, Yoshihiro Nishida e, Seiichi Kato f, Yuzuru Kamei b a
Department of Plastic and Reconstructive Surgery, Aichi Children's Health and Medical Center, Japan Department of Plastic and Reconstructive Surgery, Nagoya University Graduate School of Medicine, Japan Department of Plastic and Reconstructive Surgery, Tottori University Graduate School of Medicine, Japan d Department of Neurosurgery, Nagoya University Graduate School of Medicine, Japan e Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, Japan f Department of Pathology and Laboratory Medicine, Nagoya University Graduate School of Medicine, Japan b c
a r t i c l e i n f o
a b s t r a c t
Article history: Received 9 May 2015 Accepted 18 May 2015 Available online 20 June 2015
Parosteal lipoma is a rare benign tumor that is composed mainly of benign mature lipocytes, and it has an intimate association with the underlying affected bone. Parosteal lipoma involving the head and neck is very rare, and there are only two reported cases of parosteal lipoma of the skull in English literature. This paper reports a rare case of frontal parosteal lipoma in a young child with a hard enlargement of the forehead region after blunt trauma. Computed tomography revealed a large soft tissue mass and an osseous projection of the unilateral frontal bone. The pathology report identified lipoma and thickening of diploic space of the frontal bone. Here, we present a new case of parosteal lipoma in the frontal region. © 2015 The Authors. Published by Elsevier Ltd on behalf of British Association of Plastic, Reconstructive and Aesthetic Surgeons. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).
Keywords: Parosteal lipoma Diploic space Frontal bone Young child Post-traumatic Projection
* Corresponding author. Department of Plastic and Reconstructive Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan. Tel.: þ81 52 744 2525; fax: þ81 52 744 2527. E-mail address: [email protected] (K. Toriyama). http://dx.doi.org/10.1016/j.jpra.2015.05.003 2352-5878/© 2015 The Authors. Published by Elsevier Ltd on behalf of British Association of Plastic, Reconstructive and Aesthetic Surgeons. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
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T. Morishita et al. / JPRAS Open 5 (2015) 19e23
Introduction Lipoma is the most common subcutaneous tumor. The parosteal type is a rare tumor accounting for 0.3% of all lipomas, usually asymptomatic, and affecting mainly adults in their 40s.1 Moreover, parosteal lipoma of the skull is very rare. There have been only two reports of parosteal lipoma involving the head region.2,3 Many of the characteristics were similar to those in our case; however, the absence of periosteal reaction, the presence of thickening of diploic space and the medical history of trauma were different. Here, we present a new case of parosteal lipoma of the frontal region. Clinical report The patient fell from a high place ten months after birth and bruised his forehead on concrete. The swelling persisted and the boy was taken to see a doctor two weeks after sustaining the injury; however, there was no evidence of a bone fracture on the X-rays. Swelling was more pronounced 6 months later. Computed tomography (CT) revealed both thickening of the fat of the forehead under the frontal muscle and thickening of the frontal bone. One year after the injury occurred, the patient visited our department for the first time. His parents were concerned about the swelling on his forehead. We followed up the subsequent history of the patient by yearly Magnetic resonance imaging (MRI) in order to avoid radioactive exposure. MRI revealed that the fat under the frontal muscle had obviously thickened, while the fat of the subcutaneous layer had slightly thickened. MRI also uncovered an expansion of the diploe of the right frontal bone. There were no abnormalities intracranially. Follow-up MRI showed that the submuscular fat and the diploe had thickened gradually. We planned a surgical procedure to improve the patient's appearance and to make a pathological diagnosis at five years old (Figure 1). A preoperative view of the CT image showed a soft tumor and prominent frontal bony tumor (Figure 2A). Moreover, the frontal bone was associated with expanded diploic space; the outer table of the skull had projected outward and thinned, while the inner table of the skull slightly projected inward (Figure 2B). The area of soft tumor and frontal bony tumor fell within
Figure 1. Preoperative view at five years old.
T. Morishita et al. / JPRAS Open 5 (2015) 19e23
21
Figure 2. Preoperative images at five years old. Soft tumor (star) and thickening of diploic space (triangle) in CT image (A). Sagittal MRI showing analogous signals of the subcutaneous fat tissue (star) and diploic space (triangle) (B).
the approximate range of the right frontal bone. Interestingly, the emissary veins of the affected skull were developed. We made a coronal incision to remove the submuscular lipoma and shave the projecting frontal bone. Easy bleeding was seen during the dissection of lipoma and periosteum. A bone biopsy was performed at the top of the frontal bone, and the defect of the biopsy was filled with artificial bone. The frontal bone was then shaved with a burr to create symmetry. We preserved the supraorbital nerve while tumor resection. Finally, we replaced the elevated periosteum and closed the surgical incision with sutures. Results The postoperative course was uneventful. Histopathologic examination of the soft mass revealed a lipoma with fibrous capsule. The harvested bone showed a thinned cortical bone with a welldeveloped bone marrow with a trabecular structure. A 2-year follow up revealed no evidence of recurrence except for the thickened subcutaneous fat (Figure 3). Discussion Diagnosis of a slow-growing mass of the forehead can be challenging. Lipoma is the most common subcutaneous tumor, however, lipoma in the frontal region is relatively rare and especially osseous lipoma (the parosteal and intraosseous type) in this region is very rare.1 Cases of parosteal or intraosseous lipoma of the skull are summarized in Table 1. There are only two reports of parosteal lipoma of the skull; Cil et al2 and Murakami et al3 (Table 1). Our case shares similarities in location and pathology of the soft mass. The distinctive features of our case were no periosteal reaction and thickening of diploic space of the whole right frontal bone. On the other hand, there are a few reports of lipoma with thickening of diploic space in the skull.4,5 Nahles et al4 reported the overlying soft tissues were markedly thickened, which was very similar with our frontal parosteal lipoma. However, the histopathology was completely different from our case. Our patient was a young child who had sustained blunt trauma. Furthermore, a relationship between a blunt soft tissue trauma at the site of the tumor and the subsequent formation of lipomas has been described earlier.6 These soft tissue tumors have been named ‘post-traumatic lipomas’. Posttraumatic lipomas were located subcutaneously, superficial to the musculofascial system. There were no reports of post-traumatic lipoma associated with the underlying bone deformity.
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T. Morishita et al. / JPRAS Open 5 (2015) 19e23
Figure 3. Postoperative view two years after surgery.
Table 1 Cases of parosteal or intraosseous lipoma of the skull. Cases
Type
Authors (year)
Age, yrs (onset)
Sex
Location
Soft tissue
Skull condition
1
Parosteal
Ciel et al. (2008) Murakami et al. (2014)
17
M
Frontal
Lipoma
30
F
Parieto-occipital
Lipoma
Nahles et al. (2004)
0
F
Frontal
The thicked soft tissue
Cortical irregularity Massive hyperostosis (periosteal reaction) Expanded diploic space
4
Yasuda et al. (1987)
1
M
Fronto-parietal
Expanded diploic space
5
Yasuda et al. (1987)
0
F
Fronto-parietal
Expanded diploic space
6
Present case
1
M
Frontal
2
3
Intraosseous
Lipoma
Thickening of the diploic space
Histopathology of bone
Trauma
The reactive hyperostosis
The rarefied hematopoietic cells Mature fat cells in normal trabeculae Mature fat cells in normal trabeculae Well-developed bone marrow
Fall
We chose a minimally invasive procedure and aesthetic approach due to the patient's young age; the frontal bone was shaved to create symmetry and avoid disrupting the growth of the bone. Although the subcutaneous fat had thickened slightly, we didn't remove it surgically due to concern that it may hinder the movement of the anterior muscle of the head and show irregularities in the forehead. At present, three years post operatively, a recurrence has not occurred but some superficial lipomas remain, and further observation will be necessary in the future.
T. Morishita et al. / JPRAS Open 5 (2015) 19e23
23
Conflict of interest statement and funding source This work was not supported by any external funding. None of the remaining authors have any financial disclosures. Appendix A. Supplementary data Supplementary data related to this article can be found at http://dx.doi.org/10.1016/j.jpra.2015.05. 003. References 1. Kapukaya A, Subasi M, Dabak N, Ozkul E. Osseous lipoma: eleven new cases and review of the literature. Acta Orthop Belg. 2006;72:603e614. 2. Cil Y, Kocer NM, Yapici AK. Frontal parosteal lipoma. J Craniofac Surg. 2008;19:1122e1125. 3. Murakami M, Hirai M, Sakakibara T, Yamaki T, Kusuzaki K. Skull parosteal lipoma with reactive hyperostosis: a case report. Neurol Med Chir (Tokyo). 2014;54:314e316. 4. Nahles G, Schaeper F, Bier J, Klein M. An intraosseous lipoma in the frontal bone e a case report. Int J Maxillofac Surg. 2004; 33:408e410. 5. Yasuda Y, Tsukada S, Okada T, Haseda Y. Intraosseous lipoma of the skull: a report of two cases. Ann Plast Surg. 1987;18: 74e80. 6. Aust MC, Spies M, Kall S, et al. Lipomas after blunt soft tissue trauma: are they real? Analysis of 31 cases. Br J Dermatol. 2007; 157:92e99.
Contents lists available at ScienceDirect
JPRAS Open journal homepage: http://www.journals.elsevier.com/ jpras-open
Case report
Frontal parosteal lipoma with thickening of diploic space Tsuyoshi Morishita a, Kazuhiro Toriyama b, *, Shunjiro Yagi c, Keisuke Takanari b, Masazumi Fujii d, Yoshihiro Nishida e, Seiichi Kato f, Yuzuru Kamei b a
Department of Plastic and Reconstructive Surgery, Aichi Children's Health and Medical Center, Japan Department of Plastic and Reconstructive Surgery, Nagoya University Graduate School of Medicine, Japan Department of Plastic and Reconstructive Surgery, Tottori University Graduate School of Medicine, Japan d Department of Neurosurgery, Nagoya University Graduate School of Medicine, Japan e Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, Japan f Department of Pathology and Laboratory Medicine, Nagoya University Graduate School of Medicine, Japan b c
a r t i c l e i n f o
a b s t r a c t
Article history: Received 9 May 2015 Accepted 18 May 2015 Available online 20 June 2015
Parosteal lipoma is a rare benign tumor that is composed mainly of benign mature lipocytes, and it has an intimate association with the underlying affected bone. Parosteal lipoma involving the head and neck is very rare, and there are only two reported cases of parosteal lipoma of the skull in English literature. This paper reports a rare case of frontal parosteal lipoma in a young child with a hard enlargement of the forehead region after blunt trauma. Computed tomography revealed a large soft tissue mass and an osseous projection of the unilateral frontal bone. The pathology report identified lipoma and thickening of diploic space of the frontal bone. Here, we present a new case of parosteal lipoma in the frontal region. © 2015 The Authors. Published by Elsevier Ltd on behalf of British Association of Plastic, Reconstructive and Aesthetic Surgeons. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).
Keywords: Parosteal lipoma Diploic space Frontal bone Young child Post-traumatic Projection
* Corresponding author. Department of Plastic and Reconstructive Surgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan. Tel.: þ81 52 744 2525; fax: þ81 52 744 2527. E-mail address: [email protected] (K. Toriyama). http://dx.doi.org/10.1016/j.jpra.2015.05.003 2352-5878/© 2015 The Authors. Published by Elsevier Ltd on behalf of British Association of Plastic, Reconstructive and Aesthetic Surgeons. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
20
T. Morishita et al. / JPRAS Open 5 (2015) 19e23
Introduction Lipoma is the most common subcutaneous tumor. The parosteal type is a rare tumor accounting for 0.3% of all lipomas, usually asymptomatic, and affecting mainly adults in their 40s.1 Moreover, parosteal lipoma of the skull is very rare. There have been only two reports of parosteal lipoma involving the head region.2,3 Many of the characteristics were similar to those in our case; however, the absence of periosteal reaction, the presence of thickening of diploic space and the medical history of trauma were different. Here, we present a new case of parosteal lipoma of the frontal region. Clinical report The patient fell from a high place ten months after birth and bruised his forehead on concrete. The swelling persisted and the boy was taken to see a doctor two weeks after sustaining the injury; however, there was no evidence of a bone fracture on the X-rays. Swelling was more pronounced 6 months later. Computed tomography (CT) revealed both thickening of the fat of the forehead under the frontal muscle and thickening of the frontal bone. One year after the injury occurred, the patient visited our department for the first time. His parents were concerned about the swelling on his forehead. We followed up the subsequent history of the patient by yearly Magnetic resonance imaging (MRI) in order to avoid radioactive exposure. MRI revealed that the fat under the frontal muscle had obviously thickened, while the fat of the subcutaneous layer had slightly thickened. MRI also uncovered an expansion of the diploe of the right frontal bone. There were no abnormalities intracranially. Follow-up MRI showed that the submuscular fat and the diploe had thickened gradually. We planned a surgical procedure to improve the patient's appearance and to make a pathological diagnosis at five years old (Figure 1). A preoperative view of the CT image showed a soft tumor and prominent frontal bony tumor (Figure 2A). Moreover, the frontal bone was associated with expanded diploic space; the outer table of the skull had projected outward and thinned, while the inner table of the skull slightly projected inward (Figure 2B). The area of soft tumor and frontal bony tumor fell within
Figure 1. Preoperative view at five years old.
T. Morishita et al. / JPRAS Open 5 (2015) 19e23
21
Figure 2. Preoperative images at five years old. Soft tumor (star) and thickening of diploic space (triangle) in CT image (A). Sagittal MRI showing analogous signals of the subcutaneous fat tissue (star) and diploic space (triangle) (B).
the approximate range of the right frontal bone. Interestingly, the emissary veins of the affected skull were developed. We made a coronal incision to remove the submuscular lipoma and shave the projecting frontal bone. Easy bleeding was seen during the dissection of lipoma and periosteum. A bone biopsy was performed at the top of the frontal bone, and the defect of the biopsy was filled with artificial bone. The frontal bone was then shaved with a burr to create symmetry. We preserved the supraorbital nerve while tumor resection. Finally, we replaced the elevated periosteum and closed the surgical incision with sutures. Results The postoperative course was uneventful. Histopathologic examination of the soft mass revealed a lipoma with fibrous capsule. The harvested bone showed a thinned cortical bone with a welldeveloped bone marrow with a trabecular structure. A 2-year follow up revealed no evidence of recurrence except for the thickened subcutaneous fat (Figure 3). Discussion Diagnosis of a slow-growing mass of the forehead can be challenging. Lipoma is the most common subcutaneous tumor, however, lipoma in the frontal region is relatively rare and especially osseous lipoma (the parosteal and intraosseous type) in this region is very rare.1 Cases of parosteal or intraosseous lipoma of the skull are summarized in Table 1. There are only two reports of parosteal lipoma of the skull; Cil et al2 and Murakami et al3 (Table 1). Our case shares similarities in location and pathology of the soft mass. The distinctive features of our case were no periosteal reaction and thickening of diploic space of the whole right frontal bone. On the other hand, there are a few reports of lipoma with thickening of diploic space in the skull.4,5 Nahles et al4 reported the overlying soft tissues were markedly thickened, which was very similar with our frontal parosteal lipoma. However, the histopathology was completely different from our case. Our patient was a young child who had sustained blunt trauma. Furthermore, a relationship between a blunt soft tissue trauma at the site of the tumor and the subsequent formation of lipomas has been described earlier.6 These soft tissue tumors have been named ‘post-traumatic lipomas’. Posttraumatic lipomas were located subcutaneously, superficial to the musculofascial system. There were no reports of post-traumatic lipoma associated with the underlying bone deformity.
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T. Morishita et al. / JPRAS Open 5 (2015) 19e23
Figure 3. Postoperative view two years after surgery.
Table 1 Cases of parosteal or intraosseous lipoma of the skull. Cases
Type
Authors (year)
Age, yrs (onset)
Sex
Location
Soft tissue
Skull condition
1
Parosteal
Ciel et al. (2008) Murakami et al. (2014)
17
M
Frontal
Lipoma
30
F
Parieto-occipital
Lipoma
Nahles et al. (2004)
0
F
Frontal
The thicked soft tissue
Cortical irregularity Massive hyperostosis (periosteal reaction) Expanded diploic space
4
Yasuda et al. (1987)
1
M
Fronto-parietal
Expanded diploic space
5
Yasuda et al. (1987)
0
F
Fronto-parietal
Expanded diploic space
6
Present case
1
M
Frontal
2
3
Intraosseous
Lipoma
Thickening of the diploic space
Histopathology of bone
Trauma
The reactive hyperostosis
The rarefied hematopoietic cells Mature fat cells in normal trabeculae Mature fat cells in normal trabeculae Well-developed bone marrow
Fall
We chose a minimally invasive procedure and aesthetic approach due to the patient's young age; the frontal bone was shaved to create symmetry and avoid disrupting the growth of the bone. Although the subcutaneous fat had thickened slightly, we didn't remove it surgically due to concern that it may hinder the movement of the anterior muscle of the head and show irregularities in the forehead. At present, three years post operatively, a recurrence has not occurred but some superficial lipomas remain, and further observation will be necessary in the future.
T. Morishita et al. / JPRAS Open 5 (2015) 19e23
23
Conflict of interest statement and funding source This work was not supported by any external funding. None of the remaining authors have any financial disclosures. Appendix A. Supplementary data Supplementary data related to this article can be found at http://dx.doi.org/10.1016/j.jpra.2015.05. 003. References 1. Kapukaya A, Subasi M, Dabak N, Ozkul E. Osseous lipoma: eleven new cases and review of the literature. Acta Orthop Belg. 2006;72:603e614. 2. Cil Y, Kocer NM, Yapici AK. Frontal parosteal lipoma. J Craniofac Surg. 2008;19:1122e1125. 3. Murakami M, Hirai M, Sakakibara T, Yamaki T, Kusuzaki K. Skull parosteal lipoma with reactive hyperostosis: a case report. Neurol Med Chir (Tokyo). 2014;54:314e316. 4. Nahles G, Schaeper F, Bier J, Klein M. An intraosseous lipoma in the frontal bone e a case report. Int J Maxillofac Surg. 2004; 33:408e410. 5. Yasuda Y, Tsukada S, Okada T, Haseda Y. Intraosseous lipoma of the skull: a report of two cases. Ann Plast Surg. 1987;18: 74e80. 6. Aust MC, Spies M, Kall S, et al. Lipomas after blunt soft tissue trauma: are they real? Analysis of 31 cases. Br J Dermatol. 2007; 157:92e99.