Solitary extramedullary plasmacytoma in the lung misdiagnosed as lung cancer: A case report and literature review

Abstract

Background:

Extramedullary plasmacytoma (EMP) is an extremely rare kind of soft tissue plasma cell neoplasm without bone marrow involvement or other systemic characteristics of multiple myeloma. Primary pulmonary plasmacytoma (PPP), with no specific clinical manifestations, is an exceedingly rare type of EMP. Because of its complexity, PPP is often difficult to diagnose. Computed tomography-guided percutaneous core needle biopsy (CT-guided PCNB) has been shown to have high sensitivity, specificity and accuracy for characterization of pulmonary lesion, particularly if malignancy is suspected. Here we presented a rare case of PPP diagnosed with CT-guided PCNB.

Case presentation:

A 78-year-old female smoker who visited our outpatient clinic for a mass in the left lower lobe of the lung. Pathological based on CT-guided PCNB yielded a PPP with no lymph node or other distant metastasis.

Conclusions:

Extramedullary plasmacytoma should be considered in the differential diagnosis of a pulmonary mass.

Background

Extramedullary plasmacytoma (EMP) is a rare monoclonal plasma cell tumor involving tissues outside the bone marrow. The entity comprises approximately 3–5% of all plasma cell neoplasms. More than 80% of EMP cases occur in the head and neck, and most cases involve the upper aerodigestive tract (1). Primary pulmonary plasmacytoma (PPP) is an extremely rare variant of EMP. In a comprehensive literature search reviewing patients with PPP, only 16 reports were found (2–15) summarized in Table 1). Here, we present an extremely unusual presentation as a pulmonary mass and without bone marrow involvement. With respect to the different biologic characteristics and prognoses of PPP, it is essential to consider in differential diagnosis of lung mass. CT-guided needle aspiration biopsy should be considered as first line to gain biopsy sample.

Case presentation

A 78-year-old female with a mass in the left lower lobe of the lung was referred to our hospital. The patient was diagnosed with hypertension and coronary heart disease prior. She had an approximately 60-year history of smoking. She has suffered from post-exercising dyspnea for 3 years without any apparent cause. The patient showed up with chest pain intermittent on the left, and the dyspnea was deteriorated a half months ago. No obvious abnormalities were found in physical examinations. A routine laboratory test showed white blood cell count, 4.77 ×10⁹/L; neutrophil percentage, 50.8%; haemoglobin, 122 g/L; blood platelet count, 152×10⁹/L; urine protein +/-. Serum calcium and phosphorus were within normal ranges. The rest of the routine laboratory examinations at the time of admission showed no obvious abnormalities. A chest computed tomography (CT) scan demonstrated a well-circumscribed mass measuring 23.14 × 21.33 × 20.28 mm located in left lower lobe (Figure 1). The mass was homogeneous and without any area of calcification or necrosis on a CT plain scan. It was marginal and spiculated with adjacent pleural retraction without bronchiolar obstruction. No obvious enlarged lymph nodes were found in the mediastinum. CT data resulted in a diagnosis of peripheral lung cancer. All the tumor marker was normal in the blood. Subsequently, the patient received CT-guided needle aspiration biopsy. The histological examination of the specimen revealed multiple lymphocyte and plasma cells were accumulated (Figure 2A). Immunohistochemistry was positive for LCA (CD45) (+++), CD 138 (+++), CD 38 (+++), kappa (+++), CK (-), CD 20(-), INSM1 (-), CD 56(-) (Figures 2B–I). In addition, specific stain of pathology including PAS, GMS were negative (Figures 2J–L). Pathological biopsy indicated extramedullary plasmacytoma. The patient was further evaluated by other diagnostic tests, including urine Bence-Jones protein, serum electrophoresis (Figure 3A), urine electrophoresis (Figure 3B), and bone marrow biopsy. However, all of the above tests had no abnormal change. The PET-CT revealed solid lesions with high grade increase 18F-fluorodeoxyglucose (18F-FDG) uptake in the lower left lobe of lung. There were no signs of abnormal metabolism in other organs and tissues, and no osteolytic lesions (Figure 4). Ultimately, the patient was diagnosed with PPP.

Figure 1

Figure 2

Figure 3

Figure 4

Discussion and conclusions

In the present study, we encountered an extremely rare case of primary lung plasmacytomas without involving bone marrow. According to the classification of the Wilshaw method (4): Stage I, the tumour is confined to the primary site; stage II, the tumour has invaded local lymph nodes; and stage III, there are obvious widespread metastases. Therefore, in this case, the tumor should be classified as stage I.

Solitary plasmacytomas (SP) are rare neoplasms, involving solitary plasmacytoma of the bone (SPB), solitary extramedullary (extra-ossesous) plasmacytoma (SEP) or multiple solitary plasmacytomas (MSP) (16). Generally SP do not involve systemic manifestation or bone marrow. However, the entity has a propensity to eventually progress to MM (16). SEP is encountered more frequently in sites having a rich lymphatic drainage such as nasal cavity, nasopharynx, and upper respiratory tract (16).

In the present study, we encountered an unusual site of SEP. The average age of PPP was 60 years old, one fourth of patients were under 50 years old. No gender difference was showed. The symptoms of PPP were nonspecific and depended on the location of the neoplasms and their tumor classification. Most PPP presented solitary pulmonary masses, multiple shadowed masses was rare on CT image. Therefore, PPP is often misdiagnosed as tuberculosis or lung cancer. The imaging findings of PPP reported in the literature are mostly solitary pulmonary nodules or masses, mostly located around the hilar, with round or quasi-circular shape, relatively uniform density and clear boundary (2). A few patients also show multiple nodules, masses or diffuse lesions in the lung (3). Consistently with previous reports (2), the tumor in this case on CT image was rounded masses with well-defined margins that was initially misdiagnosed as peripheral lung cancer. There are some subtle differences between PPP and peripheral lung cancer, tuberculoma, but there is no characteristic difference. In general, peripheral lung cancer is deeply lobulated with short hard burrs. The radiography of tuberculoma shows no lobule with calcified foci, and satellite lesions around. Peripheral lung cancer shows obvious enhancement, but tuberculoma shows no or light strengthening on enhanced CT scan. PPP presents with moderate uniform reinforcement on enhanced CT scan (2). The tumor markers of pulmonary carcinoma can be elevated, while tumor marker was negative in tuberculoma and PPP. Consistent with the CT presentation of previous cases, the mass was homogeneous and necrosis and calcification are rarely seen in this case (17). Few patients showed diffuse consolidation in bilateral lung (3, 9). Castleman disease is also a lymphoproliferative disease with hyperplastic germinal center of the lymphatic node. According to the distribution of lymph nodes, it was divided into Unicentric Castlman disease and Multicentric Castlman disease. According to pathology, There are three pathologic subtype, including hyaline vascular type, plasma cell type and intermediate type (18). Unicentric Castleman’s disease, which mimic PPP, usually shows well-circumscribed and homogenous masses in mediatum with intense reinforcement on enhanced CT scan. Nevertheless, Unicentric Castleman’s disease predominantly consists of the hyaline vessel variant (90%) (19). Histopathology is the only method to make a definitive diagnosis. The feature of Castleman disease is multiple concentric rings of mantle zone lymphocytes encircling atretic follicles. However, CD 38 and CD 138 are indicative of the diagnosis of plasmacytoma, especially CD138 (2, 4). In most circumstances, features of PPP tumor cells are positive for CD138, CD38, CD45, PC, EMA, and CD20, while negative for CD15. In a few cases, CK and EMA are positive, but negative for CD45 (4).

The use of PET/CT in evaluation of plasma cell malignancy has opportunities of detecting MSP or additional bone lesions when biochemical and laboratory investigations are within normal limits (20). Eletrophoresis of most cases showed decreased albumin and increased γ globulin (3–5, 7) or M-peak (9, 14, 15). Consistent with few cases serum eletrophoresis showed normal (8, 10, 11). In this case, immunohistochemistry findings showed the infiltration of numerous lymphocyte and plasma cells positive for CD138 and CD38. PET-CT showed no evidence of osteolytic lesions and distant metastasis. Thus, a diagnosis of PPP was made.

There are no established treatments for patients with PPP. Anatomic pulmonary resection with or without radiotherapy are the most therapeutic approach for PPP (6). Adjuvant chemotherapy is usually conservative treatment in case of diffuse infiltration, aggressive lesion on histopathology, or poor local control after local surgery or radiotherapy (21, 22). Melphalan and prednisone are commonly used chemotherapy scheme (21, 22). Chemotherapy is considered in patients with tumors larger than 5cm (4). Taking into account, the size of the primary lesion without local infiltration or distant metastasis. We planned complete radiation therapy for the elderly patients with multiple comorbidities. Long-term survival in PPP remains unclear, due to limited follow-up data on too few patients. PPP has a relative favourable prognosis, as evidence by previous findings that these patients survived 10-20 years (10, 21). 20%-40% rate of progress to MM was noted (23). After 4 courses of radiotherapy, the chest X-ray became normal. Further follow-up is needed to monitor the progression of this case, and determine optimal treatment strategies for similar case.

In conclusion, we report an extremely rare presentation of SEP. This case highlights that attention should be paid to the differential diagnosis of pulmonary mass. Precise biopsy and optimal pathological evaluation will confirm the diagnosis. Doctors should be mindful of PPP as a differential diagnosis.

Acknowledgments

The authors thank the patient for her participation and her agreement to the publication of the report. We thank Tianjin Key Medical Discipline (Specialty) Construction Project.

Publisher’s note

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References

• 1

  FletcherCDM. Diagnostic histopathology of tumors. 3. London: Churchill Livingstone (2007).

  • Google Scholar

• 2

  NieSPengDCGongHHYeCLNieXLiHJ. Primary pulmonary plasmacytoma: a case report introduction. World J Surg Oncol (2016) 14(1):205. doi: 10.1186/s12957-016-0948-8

  • CrossRef
  • Google Scholar

• 3

  KimS-HKimTHSohnJWYoonHJShinDHKimISet al. Primary pulmonary plasmacytoma presenting as multiple lung nodules. Korean J Intern Med (2012) 27(1):111–3. doi: 10.3904/kjim.2012.27.1.111

  • CrossRef
  • Google Scholar

• 4

  ZhouYWangXHMengSSWangHCLiYXXuRet al. Primary pulmonar y plasmacytoma accompan ied by overlap syndrome: A case report and review of the literature. World J Clin cases (2020) 8(20):4999–5006. doi: 10.12998/wjcc.v8.i20

  • CrossRef
  • Google Scholar

• 5

  RahimYTareenFZAhmedRKhanJA. Primary pulmonary plasmacytom a presenting with rare IgG lambda monoclonal gammopathy. BMJ Case Rep (2019) 12(3):e227514. doi: 10.1136/bcr-2018-227514

  • CrossRef
  • Google Scholar

• 6

  MaqsoodUJonesHGey van PittiusDHarisM. Primary pulmonary plasmacyt oma mimicking lung cancer diagnosed on endobronchia l ultrasound (EBUS) –guided biopsy. BMJ Case Rep (2016) 2016:bcr2016215785. doi: 10.1136/bcr-2016-215785

  • CrossRef
  • Google Scholar

• 7

  ZhangLZhangXZhangRFanW. 18F-FDG PET/CT metabolic activity in a patient with solitary extramedullary plasmacytoma of the lung. Clin Nucl Med (2016) 41(3):232–4. doi: 10.1097/RLU.0000000000001030

  • CrossRef
  • Google Scholar

• 8

  CoelhoLRACoelhoGPQueirozRMValentinMVN. Extramedullary plasmacytoma in the right pulmonary hilum. Radiol Bras (2015) 48(6):401–2. doi: 10.1590/0100-3984.2015.0074

  • CrossRef
  • Google Scholar

• 9

  Mohammad TaheriZMohammadiFKarbasiMSeyfollahiLKahkoeiSGhadianyMet al. Primary pulmonary plasmacytoma with diffuse alveolar consolidation: a case report. Pathol Res Int (2010) 2010:463465. doi: 10.4061/2010/463465

  • CrossRef
  • Google Scholar

• 10

  MonteroCSoutoAVidalIFernandezMBlancoMVereaH. Three cases of primary pulmonary plasmacytoma. Arch Bronconeumol (2009) 45:564–6. doi: 10.1016/j.arbres.2009.04.009

  • CrossRef
  • Google Scholar

• 11

  LuhS-PLaiY-STsaiC-HTsaoTC-Y. Extramedullary plasmacytoma (EMP): report of a case manifested as a mediastinal mass and multiple pulmonary nodules and review of literature. World J Surg (2007) 5:123. doi: 10.1186/1477-7819-5-123

  • CrossRef
  • Google Scholar

• 12

  NiitsuNKohriMHayamaMNakamineHNakamuraNBesshoMet al. Primary pulmonary plasmacytoma involving bilateral lungs and marked hypergammaglobulinemia: differentiation from extranodal marginal zone b-cell lymphoma of mucosa-associated lymphoid tissue. Leuk Res (2005) 29(11):1361–4. doi: 10.1016/j.leukres.2005.04.009

  • CrossRef
  • Google Scholar

• 13

  JosephGPunditM. Primary pulmonary plasmacytoma. Cancer (1993) 3(27):721–4. doi: 10.1002/1097-0142(19930201)71:3<721::aid-cncr2820710311>3.0.co;2-u

  • CrossRef
  • Google Scholar

• 14

  HoriuchiTHirokawaMOyamaYKitabayashiASatohKShindohTet al. Diffuse pulmonary infiltrates as a roentgenographic manifestation of primary pulmonary plasmacytoma. Am J Med (1998) 105(1):72–4. doi: 10.1016/S0002-9343(98)00131-4

  • CrossRef
  • Google Scholar

• 15

  WiseJNSchaeferRF. Primary pulmonary plasmacytoma. Chest (2001) 120:1405–7. doi: 10.1378/chest.120.4.1405

  • CrossRef
  • Google Scholar

• 16

  KilciksizSKarakoyun-CelikOAgaogluFYHaydarogluA. A review for solitary plasmacytoma of bone and extramedullary plasmacytoma. Sci World J (2012) 2012:895765. doi: 10.1100/2012/895765

  • CrossRef
  • Google Scholar

• 17

  KanekoYSatohHHaraguchiNImagawaSSekizawaK. Radiologic findings in primary pulmonary plasmacytoma. J Thorac Imaging (2005) 20(1):53–4. doi: 10.1097/01.rti.0000139389.88019.63

  • CrossRef
  • Google Scholar

• 18

  KligermanSJAuerbachAFranksTJGalvinJR. Castleman disease of the thorax: Clinical, radiologic, and pathologic correlation: From the radiologic pathology archives. Radiographics (2016) 36(5):1309–32. doi: 10.1148/rg.2016160076

  • CrossRef
  • Google Scholar

• 19

  PribylKVakayilVFarooqiNAroraNKreitzBIkramuddinSet al. Castleman disease: A single-center case series. Int J Surg Case Rep (2021) 80:105650. doi: 10.1016/j.ijscr.2021.105650

  • CrossRef
  • Google Scholar

• 20

  BasavaiahSHLoboFDPhiliposeCSSureshPKSreeramSKiniHet al. Clinicopathological spectrum of solitary plasmacytoma: a single center experience from coastal India. BMC Cancer (2019) 19(1):801. doi: 10.1186/s12885-019-5976-7

  • CrossRef
  • Google Scholar

• 21

  EtienneGGrenouilletMGhiringhelliCVatanRLazaroEGermainPet al. Pulmonary plasmacytoma: about two new cases and review of the literature. Rev Med Interne (2004) 25:591–5. doi: 10.1016/j.revmed.2004.04.024

  • CrossRef
  • Google Scholar

• 22

  LacazeOKhaddageOCourt-FortuneITiffetOVergnonJM. Isolated intrapulmonary plasmacytoma; diagnostic and therapeutic difficulties. Rev Mal Respir (2002) 19:648–50. doi: MDOI-RMR-10-2002-19-5-0761-8425-101019-ART18

  • Google Scholar

• 23

  KossMNHochholzerLMoranCAFrizzeraG. Pulmonary plasmacytomas: a clinicopathologic and immunohistochemical study of five cases. Ann Diagn Pathol (1998) 2:1–11. doi: 10.1016/s1092-9134(98)80029-4

  • CrossRef
  • Google Scholar