| Abstract|| |
Soft tissue amyloidoma with features similar to plasmacytoma, in absence of systemic amyloidosis, is an extremely rare finding. We hereby report the case of a 77 year old man who presented with a painless, nodular swelling on chest wall, diagnosed as soft tissue amyloidoma with plasma cell infiltration. Congo red staining was done to prove the presence of amyloid which showed characteristic "apple-green" birefringence on polarized microscopy. The plasma cells were monoclonal in origin as demonstrated by serum protein and immunofixation electrophoresis. To the best of our knowledge, this is the second such reported case. However close follow up is required, as this patient may develop multiple myeloma in future.
Keywords: Extramedullary plasmacytoma, soft-tissue amyloidoma, rare
|How to cite this article:|
Dalal BS, Sarkar P, Maity N, Nadeem SM. Soft-tissue amyloidoma with associated plasmacytoma. Indian J Pathol Microbiol 2016;59:535-7
| Introduction|| |
Amyloidoma is a rare condition characterized by localized deposit of amyloid.  It is most commonly seen in the upper respiratory tract, but it has also been reported in other sites such as lung, skin, gastrointestinal tract, lower urinary tract, breast, brain, bone, and soft tissue. 
Very few cases of soft-tissue amyloidoma with associated plasmacytoma have been reported till date. ,,,,,,, We are reporting a case of soft-tissue amyloidoma with associated plasmacytoma in a 77-year-old male patient.
| Case Report|| |
A 77-year-old male presented with a nodular swelling over the chest wall. Physical examination revealed a non tender, soft to firm mass over the right side of chest wall. Computed tomographic scan and ultra sound revealed a 12 cm soft-tissue mass over the chest wall but not involving any underlying structure. The mass was excised, and a nodular partially skin-covered tissue piece measuring 11.5 cm 7 cm 6.5 cm was received. On sectioning the mass, hemorrhagic solid areas were noted. Histopathological examination of the formalin-fixed, paraffin-embedded, and hematoxylin and eosin-stained sections revealed a well-circumscribed nodular tumor involving the dermis and subcutaneous tissue. The tumor was composed of nodules of amorphous eosinophilic material along with sheets of plasma cells. The mass showed no evidence of lymphoepithelial lesion or lymphoid follicles. Many binucleated plasma cells were also seen. Overlying skin and deep margins were free [Figure 1]a and b.
|Figure 1: (a) Histology of the skin showing pink amorphous deposits in the deep dermis (H and E, ×40). (b) Dense plasma cell infiltrate around the amorphous deposits (H and E, ×400). (c) Amorphous deposits showing Congo red positivity (Congo red stain, ×40). (d) Congo red-positive deposits showing apple-green birefringence under polarized microscope (Congo red stain, polarized microscope, ×100)|
Click here to view
Special staining with Congo red for amyloid was positive [Figure 1]c. This was further confirmed by characteristic "apple-green" birefringence under polarized microscope [Figure 1]d. We performed abdominal fat pad aspiration biopsy which showed no evidence of amyloid, there by ruling out any possibility of systemic amyloidosis.
Bone marrow examination was done which revealed mildly hypocellular marrow with no excess of plasma cells.
Serum protein electrophoresis was done which showed monoclonal protein in the gamma region, and serum protein immune electrophoresis revealed monoclonal band at immunoglobulin (Ig) G and kappa regions [Figure 2]a and b.
|Figure 2: (a) Serum protein electrophoresis showing monoclonal band (M-spike) in the gamma region. (b) Serum protein immunoelectrophoresis showing monoclonal band at immunoglobulin G and kappa regions|
Click here to view
| Discussion|| |
We are reporting a case of soft-tissue amyloidosis with features of plasmacytoma. To the best of our knowledge, only two such cases with similar histological features have been reported so far, of which one was in the soft tissue and the other in the nasopharynx.
Soft-tissue amyloidoma is a rare finding. Four cases have been reported in the lower extremity. ,,, Two cases of mediastinal amyloidoma have been reported by Osnoss and Harrell  and Shaw et al.,  but none of them had plasma cell dyscrasia in bone marrow. Lipper and Kahn reported four similar cases of which three were in the soft tissue.  Largest number of cases have been reported by Krishnan et al.  Among those 14 cases, ten were located in the soft tissue with only one case showing associated plasma cell infiltration. Only two cases, similar to ours, have been reported by Yin et al. in the left posterior perirenal space and Yoshida et al. in the nasopharynx. ,
Primary soft-tissue amyloidoma with features of plasmacytoma is an uncommon finding and if present, it usually develops into plasma cell dyscrasia on further follow-up.
In our case, we did serum protein electrophoresis, which showed monoclonal protein in the gamma region and on serum protein immunoelectrophoresis monoclonal band at IgG and kappa regions were found. This helped us to rule out lymphoplasmacytic lymphoma which is a very close differential diagnosis. Bone marrow examination revealed no evidence of plasma cell dyscrasia which goes in favor of our diagnosis of a localized plasmacytoma.
Amyloidosis is essentially a systemic disease which is characterized by deposition of fibrillary proteins in extracellular spaces of various tissues and organs. Three types of amyloid proteins have been identified-amyloid light chain (AL), amyloid associated, and amyloid derived from transthyretin.  Systemic amyloidosis due to AL type of amyloid deposition is the only form which has an association with monoclonal protein. This usually tends to progress into a disseminated disease. , Finally, diagnosis and close follow-up of solitary plasmacytoma are important since most of the cases ultimately develop disseminated myeloma. 
The authors would like to thank Dr. Aniket Halder, M.B.B.S, M.D.(Pathology), DNB (Pathology), Assistant Professor, Department of Pathology, North Bengal Medical College and Hospital, for helping in this study.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Yin H, Alhasan N, Ciervo A, Zinterhofer L. Soft tissue amyloidoma with features of plasmacytoma: A case report and review. Arch Pathol Lab Med 2002;126:969-71.
Flores M, Nadarajan P, Mangham DC. Soft-tissue amyloidoma. A case report. J Bone Joint Surg Br 1998;80:654-6.
Sidoni A, Alberti PF, Bravi S, Bucciarelli E. Amyloid tumours in the soft tissues of the legs. Case report and review of the literature. Virchows Arch 1998;432:563-6.
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.
Romagnoli S, Braidotti P, Di Nuovo F, Coggi G. Amyloid tumour (amyloidoma) of the leg: Histology, immunohistochemistry and electron microscopy. Histopathology 1999;35:188-9.
Vadmal MS, Labate AM, Hajdu SI, Ricci JL. Primary amyloidoma (amyloid tumor) of soft tissue. Acta Cytol 1998;42:837-9.
Lipper S, Kahn LB. Amyloid tumor. A clinicopathologic study of four cases. Am J Surg Pathol 1978;2:141-5.
Osnoss KL, Harrell DD. Isolated mediastinal mass in primary amyloidosis. Chest 1980;78:786-8.
Shaw P, Grossman R, Fernandes BJ. Nodular mediastinal amyloidosis. Hum Pathol 1984;15:1183-5.
Yoshida A, Borkar S, Singh B, Ghossein RA, Schöder H. Incidental detection of concurrent extramedullary plasmacytoma and amyloidoma of the nasopharynx on [ 18
F] fluorodeoxyglucose positron emission tomography/computed tomography. J Clin Oncol 2008;26:5817-9.
12/1B/1B, Sree Mohan Lane, Kolkata - 700 026, West Bengal
Source of Support: None, Conflict of Interest: None
[Figure 1], [Figure 2]