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Year : 2021  |  Volume : 64  |  Issue : 4  |  Page : 810-813
Giant exophytic tumor of the leg: A case report of amyloidoma with literature review

1 Department of Pathology, Kocaeli University Faculty of Medicine, Kocaeli, Turkey
2 Department of Plastic, Reconstructive and Aesthetic Surgery, Kocaeli University Faculty of Medicine, Kocaeli, Turkey

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Date of Submission30-Jun-2020
Date of Decision09-Aug-2020
Date of Acceptance17-Feb-2021
Date of Web Publication20-Oct-2021


Amyloidosis is a heterogeneous group of diseases with the most common form being systemic distribution. The least common type of the disease is tumor formation due to deposition which is called “amyloid tumor (amyloidoma)”. Although such tumors can occur in any region of the body, extremity localization is fairly seldom. Here, we report the clinical and histopathological features of amyloidoma in an 81-year-old female patient who presented with a large rapidly growing mass in the left lower extremity.

Keywords: Amyloidoma, exophytic, extremity, giant tumor, soft tissue

How to cite this article:
Civriz AH, Vural &, Turan G, Yaşar EK. Giant exophytic tumor of the leg: A case report of amyloidoma with literature review. Indian J Pathol Microbiol 2021;64:810-3

How to cite this URL:
Civriz AH, Vural &, Turan G, Yaşar EK. Giant exophytic tumor of the leg: A case report of amyloidoma with literature review. Indian J Pathol Microbiol [serial online] 2021 [cited 2021 Nov 28];64:810-3. Available from: https://www.ijpmonline.org/text.asp?2021/64/4/810/328579

   Introduction Top

Amyloidosis is a group of diseases characterized by the extracellular accumulation of a group of misfolded proteins.[1] In H and E sections, amyloid is seen as an amorphous extracellular eosinophilic material and this material histochemically shows green birefringence with Congo red stain under polarized light.[2] Amyloidosis can occur upon the deposition of abnormal amounts of normal proteins (immunoglobulin light chain) or deposition of misfolded proteins (transthyretin) due to resistance against proteolysis. Subtypes of amyloidosis can be distinguished immunohistochemically. Light chain amyloidosis (AL), also known as primary amyloidosis, is the most common form and is characterized by the deposition of kappa and lambda light chains. Secondary amyloidosis (AA) is characterized by the deposition of amyloid A. β2-microglobulin (Hemodialysis-related) amyloidosis is characterized by the deposition of β2-microglobulin.[2],[3],[4] Systemic amyloidosis is the most common type of amyloidosis and manifests itself with the deposition in the interstitial tissues and vascular walls. Amyloidoma or amyloid tumor, on the other hand, is the least common form and is characterized by mass formation and can occur in any tissue or organ.[2],[4] This mass formation is usually seen in the lungs, larynx, bladder, tongue, and eyes, but extremity localization is rare.[1],[2],[4],[5]

Here, we reported a rare case of amyloidoma that presents with a giant tumoral mass in the left lower extremity and reviewed the histopathological features of this rare tumor in the light of the literature.

   Case Report Top

An 81-year-old female patient presented with 8 × 4 cm mass on the skin of the anterior aspect of the left tibia [Figure 1]a. She reported that the mass existed for 20 years, but showed rapid growth over the last three months following a trauma to the leg. There were no features except for hypertension and cardiac dysrhythmia in her medical history. Macroscopically, the tumor mass that was excised on suspicion of malignancy and sent to our department was 8 × 4.5 × 4 cm in size (8 cm raised from the skin) and had an ulcerated surface. The cross-sectional surface area was dirty-yellow in color and had a heterogeneous appearance with patchy calcifications [Figure 1]b. Surface epithelium appeared normal on microscopic examination but there was an extensive extracellular deposition of small and large pink amorphous materials in the interstitial areas and vascular walls, extending from the subepithelial region to the subcutaneous fatty tissue [Figure 2] and [Figure 3]. There were areas of focal calcification and osteoid metaplasia. In addition, foreign body type giant cells and massive lymphoplasmacytic inflammatory cell infiltration were observed around the accumulated material. Histochemically, amyloid was detected using Congo red [Figure 4]a and Crystal Violet stains. Based on immunohistochemical diffuse staining with Amyloid A-specific stain (Amyloid A Ab-1, mouse, Neumarkers) [Figure 4]b, the tumoral lesion was diagnosed as “amyloid tumor (amyloidoma)”.
Figure 1: Macroscopic appearance; ulcerated mass on the skin of anterior aspect of the left tibia (a); cross-sectional surface area was dirty-yellow in color, heterogeneous appearance (b)

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Figure 2: Interstitial extracellular accumulation of eosinophilic amorphous material and osteoid metaplasia in H and E section (H and Es ×40)

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Figure 3: Giant cell reaction around the eosinophilic amorphous material (H and E ×400)

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Figure 4: Accumulation of amyloid; histochemically stained with Congo Red stain (Congo red ×200) (a) and immunhistochemically stained with Amyloid AA stain (Amyloid AA ×200) (b)

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   Discussion Top

Amyloidosis is a group of diseases with quite heterogeneous subtypes, etiology, symptoms, and treatment. Amyloid tumor (amyloidoma) is the rarest form.[1],[2] As a mass lesion, it is most frequently seen in the lungs, larynx, bladder, tongue, and eyes, whereas extremity localization is fairly seldom.[2],[3] The literature in English contains a total of 25 cases with amyloid tumor of the extremity including the present case, of which eight were AL amyloid, seven were AA amyloid similar to our case, and five were β2-microglobulin subtype; subtyping was unavailable in five cases [Table 1].
Table 1: Summary of the cases with amyloid tumor of the extremity reported in the literature in English

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Extremity amyloidomas usually appear in the AL subtype [Table 1]. AL amyloidosis, also known as primary amyloidosis, is frequently associated with lymphoid tumors. It was reported that three of the eight AL amyloidoma cases reported in the extremity localization had multiple myeloma. Walsh et al. conducted a retrospective study of 10 cases of amyloidoma at different localizations and reported that deposition of AL amyloid in and under the skin can occur without a systemic disease. In line with this study, no lymphoplasmacytic disease was observed in five of the eight cases with AL amyloidoma of the extremity.[6] In our case, whose detailed hematological examination did not reveal any pathology, it was revealed that there was no known disease other than hypertension and cardiac dysrhythmia in the clinical evaluation and detailed medical history. Moreover, Amyloid A deposition was also detected immunohistochemically, and the present case was considered to have the AA amyloid subtype. AA (amyloid associated) fibril is a nonimmunoglobulin protein synthesized in the liver under inflammatory conditions. The main reasons for AA-type amyloid deposition include chronic inflammatory processes such as local trauma, surgical intervention, chronic infection, hypertension, and diabetes.[4],[5],[7] Amyloid-AA can be demonstrated immunohistochemically with monoclonal antibodies.[8] It is known that the mass has existed for years in our elderly and hypertensive case, but a significant increase in size occurred after a known trauma. Only five of the 25 reported cases in the literature had a history of trauma with the remaining having no or unclear history of trauma. However, the fact that the mass has been localized in the lower extremity in the majority of cases suggests that it might be associated with a minor trauma that could not be remembered.

The age of the cases with amyloid tumors of the extremity ranges from 36 to 88 years,[7],[9] and the present case is the oldest (81 years old) case of AA-type amyloidoma. The mean size of these tumors ranges from 1.4 cm to 27 cm[7] [Table 1]. Our case represents the second-largest tumor (8 cm) among AA amyloidosis subtypes.

Most of the cases of amyloidoma reported at the extremity localization were in the form of deeply localized nodular masses that initially cause suspicion of a neoplasm.[4] Both the giant mass in the lumbar-gluteal region reported by Dacosta et al.[10] and the present case are different from the other cases as they are exophytic.

Amyloidomas are yellow-pink tumors with variable consistencies depending on the degree of calcification. Microscopically, they frequently appear as amorphous, eosinophilic, perivascular, and interstitial substance deposition containing plasma cell infiltration and giant cells. Krisnan et al. reported metaplastic bone formation in four cases in their study consisting of 14 cases.[1] Microscopic areas of focal calcification and osteoid metaplasia were also seen in the tumor of the present case.

While excision is considered adequate in the absence of other underlying diseases that cause systemic amyloidosis (in amyloidoma cases not related to malignancy or dialysis), there is one case with recurrence that required re-excision.[7] There is limited data on the clinical prognosis of all types of amyloidomas, but it is noted that only 1% of primary cutaneous amyloidomas progress to systemic amyloidosis after excision and up to 9% of these lesions show signs of recurrent or new cutaneous lesions.[2]

Although amyloidoma is rarely encountered, these lesions that can be considered in favor of malignancy in clinical practice should be remembered in the differential diagnosis of mass lesions of the soft tissue and investigated for possibilities.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.

   References Top

Krishnan J, Chu WS, Elrod JP, Frizzera G. Tumoral presentation of amyloidosis (amyloidomas) in soft tissues. A report of 14 cases. Am J Clin Pathol 1993;100:135-44.  Back to cited text no. 1
Desai SS, Rizzo MG, Rush AJ, Rosenberg AE, Maaieh MA. Amyloidoma: A review and case report. Skeletal Radiol 2021;50:437-44.  Back to cited text no. 2
Goldblum JR, Folpe AL, Weiss SW. Enzinger and Weiss's Soft Tissue Tumors. 7th ed. Philadelphia: Elsevier Saunders; 2020. p. 1101-3.  Back to cited text no. 3
Pasternak S, Wright BA, Walsh N. Soft tissue amyloidoma of the extremities report of a case and review of the literature. Am J Dermatopathol 2007;29:152-5.  Back to cited text no. 4
Billero VL, Jacobsen AA, Miteva MI, Wulkan AJ, Marasca C, Romanelli P. Nodular cutaneous amyloidoma of the extremity secondary to chronic granulomatous inflammation in setting of sarcoidosis. J Cutan Pathol 2017;44:801-4.  Back to cited text no. 5
Walsh NM, Lano IM, Green P, Gallant C, Pasternak S, Ly TY, et al. AL amyloidoma of the skin/subcutis: Cutaneous amyloidosis, plasma cell dyscrasia or a manifestation of primary cutaneous marginal zone lymphoma? Am J Surg Pathol 2017;41:1069-76.  Back to cited text no. 6
Maheshwari AV, Muro-Cacho CA, Kransdorf MJ, Temple HT. Soft- tissue amyloidoma of the extremities: A case report and review of the literatüre. Skeletal Radiol 2009;38:287-92.  Back to cited text no. 7
Linke RP, Gartner HV, Michels H. High-sensitivity diagnosis of AA amyloidosis using congo red and immunohistochemistry detects missed amyloid deposits. J Histochem Cytochem 1995;43:863-9.  Back to cited text no. 8
Elkins CT, Scharschmidt TJ, Wakely PE. Amyloidomas of soft parts: Diagnosis by fine-needle aspiration. Diagn Cytopathol 2012;40:126-30.  Back to cited text no. 9
Da Costa JN, Matias J, Dias JS. Giant soft tissue amyloidoma of lumbar region: A case report and literature review. Eur J Plast Surg 2014;37:397-402.  Back to cited text no. 10

Correspondence Address:
Çiğdem Vural
Department of Pathology, Kocaeli University Faculty of Medicine, Kocaeli
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/IJPM.IJPM_800_20

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  [Figure 1], [Figure 2], [Figure 3], [Figure 4]

  [Table 1]


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