Primary extraosseous plasmacytoma of the parotid gland: A case report and literature review

Mandibular salivary gland plasma cell tumor in a dog

An 8-year-old, intact male, Jack Russell Terrier dog was admitted with a 10-day history of an enlargement in the right submandibular area. Clinical examination revealed a subcutaneous, solid, firmly attached and painless mass (3 × 2 cm) located in the area of the right mandibular salivary gland, in an otherwise seemingly healthy dog. Fine-needle-aspiration cytology suggested a round cell neoplasia, most consistent with a plasma cell tumor. Histopathologic and immunohistochemical (MUM1) examination, following surgical excision of the mass, confirmed the diagnosis of a plasma cell tumor embedded in the right mandibular salivary gland. Clinical staging reasonably excluded a disseminated plasma cell tumor. The dog remains healthy and in complete remission 23 months following surgical excision of the mass. Albeit rare, extramedullary plasma cell tumors can affect the salivary glands of dogs.

Primary Epithelioid Angiosarcoma of the Submandibular Gland-A Case Report with Histology-Cytology Correlation and Comprehensive Molecular Analysis

BACKGROUND

Angiosarcoma is a sarcoma that occurs in a range of tissue types, and only rarely in the salivary glands, showing a predilection for the parotid glands of older patients. Preoperative diagnosis may be challenging, especially on cytology, with significant morphological overlap with high-grade primary salivary gland carcinomas. The molecular alterations of this rare salivary gland neoplasm are also not well-characterized.

METHODS AND RESULTS

We present a case of right submandibular gland swelling in a 73-year-old male. On fine needle aspiration, including immunohistochemical stains on cell block, the tumor was initially diagnosed as poorly differentiated carcinoma. Resection of the submandibular gland revealed epithelioid angiosarcoma. We performed molecular work-up of the tumor, utilizing targeted next-generation sequencing, DNA methylation profiling and fluorescence in-situ hybridization. Histopathologic assessment revealed an infiltrative tumor comprising solid sheets of epithelioid cells. The tumor cells formed haphazardly anastomosing vascular channels with intracytoplasmic lumina containing red blood cells. On immunohistochemistry, the tumor cells were positive for CD31, CD34 and ERG. Approximately 40% of the tumor cells showed nuclear expression of GATA3. A pathogenic TP53 R267W mutation was detected on next-generation sequencing. DNA methylation analysis did not cluster the tumor with any known sarcoma type. Copy number analysis showed possible MYC amplification and CDKN2A losses, although only the latter was confirmed on fluorescence in-situ hybridization.

CONCLUSION

Epithelioid angiosarcoma is an important differential diagnosis to high-grade salivary gland carcinoma. In particular, GATA3 expression may be encountered in both angiosarcoma and high-grade salivary gland carcinomas and cause diagnostic confusion. Identification of TP53 mutations and CDKN2A losses suggest shared oncogenic pathways with soft tissue angiosarcomas, and should be further investigated.

Fine-needle aspiration cytology for the diagnosis of plasma cell neoplasms in the head and neck region: A systematic analysis of the literature

BACKGROUND

Cytopathologic analysis is feasible and provides detailed morphological characterisation of head and neck lesions.

AIMS

To integrate the available data published on fine-needle aspiration cytology (FNAC) used for the diagnosis of plasma cell neoplasms (PCN) of the head and neck region.

MATERIALS AND METHODS

Searches on PubMed, Web of Science, Embase, and Scopus were performed to compile data from case reports/case series published in English. The Joanna Briggs Institute tool was used for the critical appraisal of studies.

RESULTS

A total of 82 studies comprising 102 patients were included in this review. There was a predilection for men (68.6%) (male/female ratio: 2.1:1). Individuals in their 50s (29.4%), 60s (22.5%), and 70s (22.5%) were more often affected. The thyroid gland (26.2%) was the main anatomical location, followed by scalp (15.5%), neck/cervical region (15.5%), jaws (13.6%), and major salivary glands (13.6%). For FNAC analysis, a smear was employed in 41 (40.6%) cases and a cell block was used in four (3.9%). In 56 (55.4%) reports, no cytological methods were available. Morphologically, 34 (56.7%) cases had a diagnosis of PCN with agreement between cytopathology and histopathology. The rate of wrong diagnoses when using cytology was 27.5%. Immunophenotyping was performed in 49 (48%) of the cases. The 69-month disease-free survival rate was 60.2%, while the 27-month overall survival rate was 64.1%.

CONCLUSION

This study reinforces that FNAC can be an ancillary tool in the first step towards the diagnosis of PCN of the head and neck region, especially when applying a cell block for cytological analysis.

Parotid Salivary Gland Extramedullary Plasmacytoma with Local Lymph Node Metastasis in a Dog

A 12 yr old spayed female mixed-breed dog presented for evaluation of a recurrent soft-tissue sarcoma. On physical examination, a firm mass was palpated ventral to the left ramus of the mandible. A fine-needle aspirate of the mass was suggestive of a round-cell neoplasm. A complete blood count, serum biochemical profile, and an abdominal ultrasound with liver and splenic aspirates were performed, and no clinically relevant abnormalities were identified. Advanced imaging of the skull identified an enlarged parotid salivary gland and an enlarged ipsilateral medial retropharyngeal lymph node. The medial retropharyngeal lymph node was sampled via fine-needle aspiration, and a round-cell population similar to what was present in the mass was identified. An incisional biopsy was performed under general anesthesia, which yielded a diagnosis of salivary gland extramedullary plasmacytoma, confirmed with immunohistochemistry (MUM-1). The parotid salivary gland and medial retropharyngeal lymph node were then surgically excised, and metastasis to the lymph node was confirmed by histopathology. The dog remained alive for 685 days after surgery until she was euthanized for hindlimb paresis of undetermined cause.

Solitary extramedullary plasmacytoma of the parotid gland in a patient with mixed connective tissue disease

Solitary extramedullary plasmacytomas of the head and neck region are rare entities. Very few have been described in the parotid gland. They can clinically and radiologically mimic the rather common benign tumors of the parotid gland (pleomorphic adenoma and Wharthin's tumor), and subsequently the need careful consideration by the involving surgeon and pathologist is needed for a proper diagnosis. In the present study, a case of solitary extramedullary plasmacytoma in the left parotid gland of a 55-year-old patient with mixed connective tissue disease is reported, along with the relevant clinical, imaging, operative, and histopathological findings. Postoperative hematological investigation to confirm the singularity of the lesion was performed. Complementary treatment with radiotherapy was followed. Disease-free, 1 year follow up is also presented.

Outside the box-Surgery for aggressive plasmacytoma in scar

This report introduces the concept of large-scale surgery and reconstruction when all other medical means of treatment have failed. In select cases, this may act as a mode of buying time and allowing the patient to receive second- or third-line treatments.