Extramedullary Plasmacytoma of the Nasal Cavity, Paranasal Sinuses, and Nasopharynx: Report of Two Cases and Review of Literature

Abstract

Extramedullary plasmacytoma (EMP) is a rare plasma cell neoplasm occurring outside the bone marrow, predominantly in the head and neck region. Representing 3%–5% of all plasma cell neoplasms, EMP poses significant diagnostic and therapeutic challenges due to its rarity and,proximity to vital structures. We report two cases of EMP involving the nasal cavity, paranasal sinuses, and nasopharynx. A 30-year-old male presented with right diplopia, headache, and bilateral nasal blockage. Examination revealed a nasopharyngeal mass with bony erosion and multiple osteolytic lesions. Histopathology and immunohistochemistry confirmed plasmacytoma, and systemic involvement was excluded. The patient underwent chemoradiotherapy with satisfactory outcomes. A 27-year-old female presented with nasal bleeding, progressive nasal blockage, facial swelling, snoring, and anosmia. Imaging revealed a mass originating from the left maxillary sinus extending to adjacent structures. Histopathology and immunohistochemistry confirmed plasmacytoma. Systemic workup was negative. The patient was treated with radiotherapy, with a good treatment outcomes. EMP of the nasal cavity, paranasal sinuses, and nasopharynx is rare, particularly in younger patients.

Accurate diagnosis and appropriate treatment, often involving radiotherapy, are crucial for favorable outcomes. Awareness and a high index of suspicion are essential for early diagnosis and management.

Introduction

Extramedullary plasmacytoma (EMP) is a rare plasma cell neoplasm that occurs outside the bone marrow. It is characterised by a neoplastic proliferation of a single clone of plasma cells, producing a monoclonal immunoglobulin.[1] Most EMPs occur in the head and neck region, primarily in the upper aerodigestive tract commonly affecting the nasal cavity, paranasal sinuses, tonsillar fossa, nasopharynx, and oral cavity.[2,3] It can also occur in other parts of the body such as the gastrointestinal tract, urinary bladder, glands, lymph nodes, liver, orbit, and skin.[1,4,5,6,7] It accounts for approximately 3%–5% of all plasma cell neoplasms, others being medullary plasmacytoma and multiple myeloma. A 3:1 prevalence ratio with male predominance was reported in sites involving the upper airway tract. The EMP is generally a localized disease with involvement of the lymph nodes being 10%–20%.

The diagnosis of EMP is based on clinical evaluation and the histologic and immunohistochemical findings of a localised collection of monoclonal plasma cells in the absence of plasma cell proliferation at other sites, especially in the bone marrow, and no evidence of multiple myeloma.[8] The investigations that are carried out to exclude systemic involvement include a haematological workup with full blood count (FBC) and erythrocyte sedimentation rate, serum and urine protein electrophoresis and immunoelectrophoresis, quantitative immunoglobulin (Ig) determination, bone marrow biopsies, and skeletal survey.[8] A conversion from EMP to multiple myeloma was described in the literature with the risk varying between 8% and 31%.[9]

Galieni et al. established five criteria for diagnosing EMP which are as follows: Biopsy of the tissue must reveal monoclonal plasma cell histology, bone marrow plasma cell infiltration should not exceed 5% of all nucleated cells, osteolytic bone lesions and involvement of other tissues must be absent, hypercalcemia and renal failure must be absent, and lastly, a serum M protein concentration, if present, must be low.[10]

Because of the rarity of the disease, it poses a diagnostic and treatment challenge to the surgeons.[11] Most of the EMPs in the head and neck are in the vicinity of vital structures; extensive surgery for removal of large tumors with adequate margins would result in disfigurement; therefore, many consider radiotherapy the treatment of choice because the tumour is radiosensitive.[12] Surgery is recommended for lesions that are localised and can be excised without much morbidity.[11] Endoscopic excision, laser excision, and excision biopsy have been described for nasal and cervical lesions; these procedures are usually combined with adjunctive radiotherapy, which may either precede or follow surgery.

Due to the rarity of this disease, we share the two cases of EMP in the nasal cavity and paranasal sinuses and nasopharynx we managed in our centre, their presentation, and diagnosis and treatment were discussed.

Case 1

A 30-year-old man presented with complaints of right-sided diplopia, an 18-month history of headaches, and progressive bilateral nasal obstruction for the past 8 months. He also reported associated right ear hearing loss and tinnitus but denied experiencing vertigo, otalgia, convulsions, loss of consciousness, visual loss, proptosis, or epistaxis.

Examination of the nose revealed a normal external appearance with reduced nasal patency and a fleshy mass in the left nasal cavity that bled upon contact and was sensitive to touch. Nasal endoscopy revealed the mass arising in the nasopharynx, obstructing both Eustachian tubes and obliterating both fossae of Rosenmüller. A CT scan showed an extensive isodense lesion in the nasopharynx extending to the choana, involving the posterior ethmoid and sphenoid sinuses, and extending to the middle cranial fossa. There was a bony erosion of the skull base with multiple osteolytic lesions. [Figure 1]

Figure 1.

An iso-dense lesion in the nasopharynx involving the posterior ethmoid and sphenoid sinuses with bony erosion of the skull base and multiple osteolytic lesions

Histological examination revealed lymphoid tissues lined by the respiratory-type epithelium, including secondary follicles and lymphocyte exocytosis, with diffuse proliferation of plasma cells, including atypical forms. The plasma cells were situated in a scanty vascular stroma with areas of necrosis. Immunohistochemistry showed the following results: CD45-positive (leucocyte common antigen), CD20-negative, and CD5-negative, leading to a conclusion of plasmacytoma of the nasopharynx.

Further investigations included a full blood count, which yielded normal results; serum electrolytes and creatinine levels indicated normal renal function; normal serum calcium levels; no Bence–Jones protein in the urine; a normal bone marrow biopsy; and other skeletal surveys using X-rays yielded normal results. The findings were consistent with a diagnosis of EMP.

The patient was reviewed by a radio-oncologist and treated with chemoradiotherapy. Initially, he received six cycles of chemotherapy with the following regimen: cisplatin at 75 mg/m², adriamycin (doxorubicin) at 50 mg/m², and cyclophosphamide at 750 mg/m². This was followed by radiotherapy, during which he received a total dose of 67.5 Gy at 2.5 Gy per day for 27 cycles, resulting in significant improvement. After the 2nd course of chemotherapy, the patient had severe anemia, which was corrected with blood transfusion.

Case 2

A 27-year-old woman presented with a 7-year history of recurrent episodes of nosebleeds. The bleeding was mild and unprovoked, with an estimated blood loss of 5–10 mL per episode. She later developed progressive left-sided nasal blockage, accompanied by nasal and facial swelling, which more pronounced on the left side. She also experienced difficulty breathing, snoring, and anosmia.

Examination revealed asymmetry of the external nose with splaying on the left side, a growth in the left nasal cavity that completely obstructed the nasal passage with contact bleeding, and a septum deviated to the right side. A computed tomography scan (CT scan) of the paranasal sinuses showed a large soft tissue mass originating from the left maxillary sinus, extending to the nasopharynx, soft palate, and the frontal, sphenoidal, and ethmoidal sinuses with bony destruction [Figure 2]. A nasal biopsy was performed, and histology revealed a tumor composed of sheets of medium- to large-sized cells with moderate-to-abundant eosinophilic cytoplasm and eccentric nuclei. Areas of plasma cell infiltration and haemorrhage were noted. [Figure 3] Immunohistochemistry revealed CD138- and CD38-positive and CD20-negative status, leading to a diagnosis of plasmacytoma.

Figure 2.

CT scan (axial view) showing an isodense lesion in the left maxillary sinus extending to the nasal cavity and nasopharynx with areas of calcifications and deviating the septum to the right side

Figure 3.

Histological section of a tumour showing plasma cell infiltrations with eosinophilic cytoplasm and eccentric nuclei

She was reviewed by a haematologist–oncologist and further evaluated with a full blood count that showed features of hypochromic normocytic anemia. Urinary Bence–Jones protein was negative, and serum electrolytes, creatinine, and calcium were normal. Bone marrow biopsy was normal, and a skeletal survey did not reveal any abnormalities. The diagnosis was consistent with EMP of the paranasal region.

The patient was treated with radiotherapy, receiving a total dose of 67.5 Gy at 2.5 Gy per day for 27 cycles, resulting in a positive response.

Discussion

Extramedullary plasmacytoma (EMP) is a rare neoplasm, with a predilection for the head and neck region.[13,14] The two cases reported here involve a 30-year-old male and a 27-year-old female, both of whom presented with atypical symptoms and were diagnosed with EMP affecting the nasal cavity, paranasal sinuses, and nasopharynx. This discussion compares the age, sex, presentation, treatment, and survival rates of these cases with similar cases reported in the literature.

The literature indicates that EMP typically occurs in the fifties to seventies and shows a male predominance, with a male-to-female ratio of approximately 3:1 for cases involving the upper airway tract.[3,10] However, our cases involve younger individuals, aged 30 and 27, which deviates from the usual age distribution. Similar findings were reported by Bachar et al.,[8] who documented an age range of 31–95 years, reinforcing the rarity of such cases in younger patients. Furthermore, the male predominance seen in our first case aligns with that observed in broader literature, although the female patient in the second case illustrates that EMP can also affect younger women.

The presentation of EMP often relates to the tumor’s location. Common symptoms include epistaxis, nasal obstruction, and facial swelling due to the compression or obstruction of local structures.[8,15] Our first case showed atypical presentations of diplopia and headache, leading initially to a neurosurgical referral, highlighting the potential for varied and misleading symptoms. In contrast, the second case had more typical symptoms, including nasal bleeding, obstruction, and facial swelling, which are consistent with findings in other studies from Nigeria, Africa, and globally.

In Nigeria and other African countries, similar cases have been reported with presentations including nasal obstruction, epistaxis, and facial swelling.[11,16,17] For instance, a study by Grover et al.[11] reported EMP cases presenting with epistaxis and nasal blockage, consistent with the findings of our second case. Globally, studies have documented similar symptoms, further supporting the commonality of these presentations in EMP of the head and neck.

The treatment for EMP generally involves radiotherapy due to the tumor’s radiosensitivity.[9,18] Surgical options are considered for localized lesions that can be excised without significant morbidity.[11] Chemotherapy is commonly not employed in EMP even if local lymph nodes are involved, except in case of large tumours, refractory or persistent tumours.[19] In our first case, chemoradiotherapy was employed, reflecting the combined approach sometimes necessary for treating extensive disease. The second case was treated with radiotherapy alone, which is often the standard treatment modality for EMP in the head and neck region.

Radiotherapy doses and schedules vary, but studies suggest that doses between 40 and 50 Gy are effective.[8,12] The two patients received a total dose of 67.5 Gy over 27 cycles. This higher dose was likely chosen due to the extensive nature of the lesion. A study by Rangeard et al. showed better local disease control for a radiotherapy dose above 45Gy.[20]

Survival rates for EMP are generally favorable, with a 5-year survival rate ranging from 50% to 80%.[3] The risk of progression to multiple myeloma varies, with studies indicating rates between 8% and 31%.[9] Both patients in our report have shown positive responses to treatment so far, aligning with the optimistic prognosis often associated with localized EMP.

Conclusion

Our cases highlight the variability in the age and presentation of EMP, underscoring the importance of considering this diagnosis even in younger patients and those with atypical symptoms. The treatment approaches in our cases are consistent with those reported in the literature, emphasizing the central role of radiotherapy. Overall, the outcomes for EMP are generally positive, provided accurate diagnosis, and appropriate treatment modalities are administered.

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.

Conflicts of interests

There are no conflicts of interests.

Funding Statement

Nil.