Intraocular extramedullary plasmacytoma in a cat

Conjunctival Extramedullary Plasmacytoma in Dogs and a Cat: Clinical Characteristics and Histopathological Findings

Simple Summary

Extramedullary plasmacytoma has been occasionally reported to affect the ocular and periocular (orbit, conjunctiva) region. To better describe the clinical and histopathological features of extramedullary plasmacytoma, we reviewed the records of seven cases (six dogs, one cat). In these cases, extramedullary plasmacytoma was found mostly in the conjunctiva of the third eyelid in the form of salmon-colored nodules with clear borders. All tumors were surgically removed with no additional therapy. No signs of recurrence or systemic involvement (multiple myeloma) were observed in the follow up period. We recommend that extramedullary plasmacytoma should be considered in cases of canine and feline conjunctival masses, followed by investigations to rule out multiple myeloma. Our results suggest that conjunctival extramedullary plasmacytoma is unlikely to recur or spread, and that local surgical excision alone or combined with cryotherapy should be curative.

Abstract

Background: Extramedullary plasmacytoma (EMP) is a plasma cell tumor that is very rarely reported in ocular and adnexal tissue and is usually solitary and benign. Methods: This study evaluated seven cases from different ophthalmology referrals submitted for histopathological analysis between 2013 and 2022. Results: EMPs were diagnosed in a 9-year-old domestic short-haired cat and in six dogs (median age, 10 years): three English Cocker Spaniels, a Golden Retriever, a Maltese, and a Pinscher. EMPs affected the third eyelid conjunctiva in five cases (5/7), followed by the superior bulbar (1/7) and palpebral conjunctivae (1/7), respectively, and were presented mostly as well-defined, salmon-colored nodules. Histopathologically, the masses were composed of sheets and packets of round cells morphologically consistent with mature plasma cells with mild anisocytosis and anisokaryosis; mitosis and binucleated giant cells were rarely observed. Follow up for 6/7 cases ranged from 6 months to 2 years. No signs of recurrence or systemic involvement (multiple myeloma) were observed. Conclusions: EMP should be included in the differential diagnoses of canine and feline conjunctival masses. Staging recommendations should include multiple myeloma diagnostic evaluation. Our results suggest that primary conjunctival EMP does not appear to be locally aggressive and has low systemic involvement behavior. The local surgical excision alone or combined with cryotherapy should be curative.

Fine needle aspiration cytology in feline skeletal muscle as a diagnostic tool for extramedullary plasmacytoma

ABSTRACT Extramedullary noncutaneous plasmacytoma (ENP) is a myeloproliferative disorder of plasma cells that rarely affects cats. This paper describes an ENP case revealed by fine needle aspiration cytology (FNAC) of the mass in the skeletal muscle of an 8-month-old, male, mixed breed cat, which had a nodule in the left hind limb. The rapid immunoassay test confirmed the presence of feline leukemia virus (FeLV). The animal necropsy macroscopically showed the nodule came from the semimembranosus muscle. Histopathological examination ratified the cytological findings. Thus, this paper alerts to the existence of plasmacytoma located in the skeletal muscle of feline species. FNAC is a quick and efficient method for diagnosis of ENP.

Feline Respiratory Extramedullary Plasmacytoma with Lymph Node Metastasis and Intrahistiocytic Amyloid

A 14-year-old domestic longhaired cat presented with a 2-year history of nasal discharge and a recent onset of inappetence and submandibular lymphadenopathy. The cat was humanely destroyed after developing severe respiratory distress. Necropsy examination revealed thickened nasal turbinates and soft palate, and friable red–tan material within the frontal sinus, nasal cavity and nasopharynx. The lungs contained multifocal irregular friable tan nodules. Multiple lymph nodes were enlarged, friable and red–tan in colour. Histopathology revealed a mature type extramedullary plasmacytoma (EMP) within the frontal sinus, nasal cavity, soft palate, larynx, trachea, lungs and multiple lymph nodes. The lymph nodes and larynx also contained marked granulomatous inflammation with extensive intrahistiocytic (and lesser amounts of extracellular) lambda light chain amyloid, confirmed by electron microscopy and immunohistochemistry. Neoplastic cells expressed CD79a and MUM1. This is the first report of an infiltrative EMP of the feline respiratory tract with lymph node metastasis and predominantly intrahistiocytic amyloid.

Sinonasal plasmacytoma in a cat

A 13-year-old female spayed Domestic Shorthair cat presented with a history of right-sided mucopurulent nasal discharge for 18 months. Computed tomography revealed a mass within the right nasal cavity and the right frontal sinus. The animal was euthanized, and a postmortem examination was performed. On macroscopic examination, the right nasal cavity and the right frontal sinus were partially occluded by a soft whitish mass. Microscopically, the mass was composed of well-differentiated plasma cells that were immunopositive for immunoglobulin G and lambda light chains. These findings were consistent with a mature-type sinonasal plasmacytoma. In addition, there was right-sided mucopurulent rhinitis and sinusitis caused by a Pasteurella infection, which probably developed secondary to the sinonasal plasmacytoma. To the authors' knowledge, this is the first report of a sinonasal plasmacytoma in a cat. The present communication shows that feline sinonasal plasmacytomas should be included in the differential diagnosis for tumors located in the upper respiratory tract of cats.

Myeloma-related disorders in cats commonly present as extramedullary neoplasms in contrast to myeloma in human patients: 24 cases with clinical follow-up

BACKGROUND

Myeloma-related disorders (MRD) are rare neoplasms of plasma cells. Published case reports describe a diversity of clinical presentations with confusing terminology and diagnostic criteria as a consequence of the assumption that MRD in cats are analogous to those in dogs or humans.

OBJECTIVE

The aim of the study was to describe clinical, clinicopathologic and imaging findings, response to treatment, survival and possible associations with other diseases or vaccination in a large case series. A priori hypotheses were that cats with MRD commonly present with extramedullary involvement and uncommonly have radiographic bone lesions, in contrast to human patients.

ANIMALS

Twenty-four cats with MRD confirmed by cytology or histopathology and immunohistochemistry.

METHOD

A multicenter retrospective study was performed.

RESULTS

Two types of clinical presentation were observed. The first group (n = 17) had neoplasia involving abdominal organs, bone marrow, or both. All developed systemic clinical signs and paraproteinemia. Five of 7 cats that received chemotherapy improved clinically or had decreased serum globulin concentration (median survival, 12.3 months; range, 8.5-22 months). The second group comprised 7 cats with skin masses, 2 of which were paraproteinemic and developed rapidly worsening systemic signs. In cats without systemic signs, excision of the skin masses appeared to be associated with prolonged survival (up to 2.4 years). Cats with MRD commonly presented with extramedullary involvement (67%), versus humans with MRD (5%) (P < .001), and uncommonly presented with radiographic bone lesions (8%) versus humans with MRD (80%) (P < .001).

CONCLUSIONS

Radiographic bone lesions are uncommon in cats with MRD and extramedullary presentation is common, relative to human myeloma.

Myeloma-related disorders in cats commonly present as extramedullary neoplasms in contrast to myeloma in human patients: 24 cases with clinical follow-up

BACKGROUND

Myeloma-related disorders (MRD) are rare neoplasms of plasma cells. Published case reports describe a diversity of clinical presentations with confusing terminology and diagnostic criteria as a consequence of the assumption that MRD in cats are analogous to those in dogs or humans.

OBJECTIVE

The aim of the study was to describe clinical, clinicopathologic and imaging findings, response to treatment, survival and possible associations with other diseases or vaccination in a large case series. A priori hypotheses were that cats with MRD commonly present with extramedullary involvement and uncommonly have radiographic bone lesions, in contrast to human patients.

ANIMALS

Twenty-four cats with MRD confirmed by cytology or histopathology and immunohistochemistry.

METHOD

A multicenter retrospective study was performed.

RESULTS

Two types of clinical presentation were observed. The first group (n = 17) had neoplasia involving abdominal organs, bone marrow, or both. All developed systemic clinical signs and paraproteinemia. Five of 7 cats that received chemotherapy improved clinically or had decreased serum globulin concentration (median survival, 12.3 months; range, 8.5-22 months). The second group comprised 7 cats with skin masses, 2 of which were paraproteinemic and developed rapidly worsening systemic signs. In cats without systemic signs, excision of the skin masses appeared to be associated with prolonged survival (up to 2.4 years). Cats with MRD commonly presented with extramedullary involvement (67%), versus humans with MRD (5%) (P < .001), and uncommonly presented with radiographic bone lesions (8%) versus humans with MRD (80%) (P < .001).

CONCLUSIONS

Radiographic bone lesions are uncommon in cats with MRD and extramedullary presentation is common, relative to human myeloma.