|LETTER TO THE EDITOR
|Year : 2014 | Volume
| Issue : 2 | Page : 143-145
Foreign body granuloma mimicking a soft-tissue tumor
Hari Charan Perigela, Koti Reddy, Vara Prasad Bangi, Narahari Janjala
Department of General Surgery, Kurnool Medical College and Government General Hospital, Kurnool, Andhra Pradesh, India
|Date of Web Publication||20-Jun-2014|
Hari Charan Perigela
Department of General Surgery, Kurnool Medical College and Government General Hospital, Kurnool, Andhra Pradesh
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Perigela HC, Reddy K, Bangi VP, Janjala N. Foreign body granuloma mimicking a soft-tissue tumor. J NTR Univ Health Sci 2014;3:143-5
Foreign body granuloma is a tissue reaction for retained foreign bodies after skin penetrating trauma. Detection of retained foreign bodies can be extremely difficult when the patient presents with non-specific symptoms such as pain and/or swelling without recognizing a previous trauma. Penetrating wounds of the lower limb are not uncommon. Many are caused by thorns or by fragments of wood that are retained in the limb, creating a foreign-body granuloma. We report a case of a boy who suffered from a thorn induced swelling in the right leg which posed diagnostic difficulties.
A 14-year-old boy presented with progressive swelling in the back of the right leg [Figure 1]. He had the symptoms for 2 years. He could recall no history of trauma. Physical examination showed a healthy patient with an oval mass on the posterior region of the right leg measuring 7 cm × 5 cm in diameter. The overlying skin was intact. There were no pressure symptoms. Fine-needle aspiration cytology (FNAC) test reported as soft-tissue sarcoma. A radiograph and ultrasound of the right leg showed evidence of soft-tissue mass. Magnetic resonance imaging (MRI) of the right leg showed soft-tissue swelling [Figure 2]. Routine investigations were within normal limits.
|Figure 1: Clinical photograph showing swelling on the posterior aspect of right leg|
Click here to view
|Figure 2: Magnetic resonance imaging of the right lower limb showing evidence of swelling|
Click here to view
Vertical incision was given over the swelling. As FNAC reported sarcoma, we thought of excising whole muscle along with the tumor. After seeing the swelling, we decided to open the swelling which was arising from the muscle. Dark colored fluid was drained after the incision over the tumor. We extended the incision and found a thorn of 2.5 cm in the tumor bed. We removed it [Figure 3]. Bits of surrounding tissue were removed and the wound was sutured in layers. After surgery, when we stressed about the history of injury, he said that he had sustained thorn prick injury 2 years back, but he forgot about it thinking that it has been a superficial injury. Patient was discharged on 8 th post-operative day after suture removal. Final diagnosis of granuloma was confirmed by histpathological examination of the tumor bits.
Foreign body granuloma is mainly divided into iatrogenic gossypiboma by retained surgical sponge during operation  and granulation by a penetrating foreign body such as wooden splinter or other materials.  If a history of antecedent skin penetrating trauma or previous operation is recognized, it is important to take foreign body granuloma into consideration as differential diagnosis from soft-tissue tumors. However, in cases where the history of trauma is uncertain and more over the patients present for evaluation several months or even years after the initial injury, the radiological appearance of foreign body granuloma can be confusing and can even mimic a neoplasm.  There have been few reports to describe overall radiological imaging features including computed tomography (CT), MRI and/or sonography of foreign body granulomas. 
The morphology of the lesions varies widely depending on the type of the material involved, the size of the foreign body and the site of trauma. Even when the history of previous trauma is not obtained, a foreign body granuloma should be ruled out whenever we see patients with a soft-tissue tumor in the extremities.
Plain radiography should be taken when the existence of foreign bodies is suspected. If the foreign body is radiopaque, we can easily identify the foreign body. Plain radiography has been reported to reveal a wooden foreign body in only 15% of patients. If there is concern about the existence of foreign bodies, ultrasonography should be used. Given the markedly different acoustic impedance of foreign bodies, such as wood and soft-tissues, they are easily identified as echogenic ones with marked posterior acoustic shadowing. Foreign bodies are also surrounded by hypoechoic halos, which consist of reactive lesions such as hematoma, edema and granulation tissue.
CT has been reported to be useful for identifying foreign bodies.  CT is superior to MRI to identify radiopaque foreign bodies but does not have an advantage for detection of radiolucent foreign bodies and visualization of the surrounding reactive lesion. MRI shows the foreign bodies as low signal or signal void to the muscles on both T1- and T2-weighted images.  When a foreign body is surrounded by inflammatory tissues or a hematoma, a ring of low signal on T1- and high signal on T2-weighted images around the foreign bodies is observed demonstrating a target appearance. The surrounding reactive lesion is easily mistaken for a soft-tissue neoplasm when a foreign body is not identified because the peripheral area of the lesion is strongly enhanced by gadolinium. The central area of the reactive lesion is observed as low intensities on T1- and high intensities on T2-weighted images with no enhancement, which suggests that the lesion is myxomatous or cystic. The key to diagnose correctly on MRI is identification of a low signal or signal void lesion inside the mass and the surrounding ring-like reactive lesion.
In conclusion, the human body especially the upper and lower limbs are inevitably exposed to skin-penetrating trauma. When foreign body granulomas are suspected, it is better to cut open the swelling as we did in the present case to confirm correct diagnosis and to avoid radical surgery.
| References|| |
|1.||Puri A, Anchan C, Jambhekar NA, Agarwal MG, Badwe RA. Recurrent gossypiboma in the thigh. Skeletal Radiol 2007;36 Suppl 1:S95-100. |
|2.||Monu JU, McManus CM, Ward WG, Haygood TM, Pope TL Jr, Bohrer SP. Soft-tissue masses caused by long-standing foreign bodies in the extremities: MR imaging findings. AJR Am J Roentgenol 1995;165:395-7. |
|3.||Laor T, Barnewolt CE. Nonradiopaque penetrating foreign body: "A sticky situation". Pediatr Radiol 1999;29:702-4. |
|4.||Peterson JJ, Bancroft LW, Kransdorf MJ. Wooden foreign bodies: Imaging appearance. AJR Am J Roentgenol 2002;178:557-62. |
|5.||Bodne D, Quinn SF, Cochran CF. Imaging foreign glass and wooden bodies of the extremities with CT and MR. J Comput Assist Tomogr 1988;12:608-11. |
[Figure 1], [Figure 2], [Figure 3]