Subcutaneous emphysema and pneumomediastinum following orbital blowout pathological fracture in a cat with nasal lymphoma: a case report

Abstract

Background: Subcutaneous emphysema and pneumomediastinum are rare complications associated with orbital blowout pathological fracture.

Case presentation: A 7-year old, castrated male Abbysinian cat presented with anorexia, lethargy, nausea, eyelid swelling, nasal discharge, and sneezing. Based on the clinical and diagnostic work-up, the cat was diagnosed with T cell high-grade nasal lymphoma associated with orbital pathological fracture due to the tumour invasion. After chemotherapy, the cat showed massive subcutaneous emphysema from frontal region to abdomen and pneumomediastinum due to orbital blowout pathological fracture. As the nasal mass decreased in volume; the air had moved from the maxillary sinus to the subcutaneous region and the mediastinum through fascial planes in the head and neck region.

Conclusions: This is a first case report of a massive subcutaneous emphysema and pneumomediastinum due to an orbital blowout pathological fracture following chemotherapy in feline nasal lymphoma in veterinary medicine.

Keywords: Blowout fracture; Cat; Chemotherapy; Lymphoma; Pneumomediastinum.

Fig. 1

Clinical photographs showing therapeutic response of nasal lymphoma after chemotherapy. A) Before chemotherapy. B) 9 h after chemotherapy (injection of L-asparaginase 400 U/kg subcutaneously). C) 20 h after chemotherapy. D) 45 h after chemotherapy (24 h after injection of vincristine 0.5 mg/m² intravenously)

Fig. 2

Transverse (A) and dorsal (B) plane computed tomography images after contrast enhancement. There is a mass protruding from the right nasal cavity (arrows) with lytic change of the medial wall of the right orbit. The mass is characterized by heterogeneous contrast enhancement with rim enhancement, causing deviation of the right eyeball

Fig. 3

Histopathology and immunohistochemistry of the nasal mass. A) Histopathology (hematoxylin and eosin stain) of the nasal mass. Neoplastic cells have distinct cell borders, minimal cytoplasm, and occasionally one prominent nucleolus. There is moderate anisocytosis and anisokaryosis (×40). B) CD3 stain. Approximately 60–75% of cells demonstrate positive cytoplasmic immunoreactivity, with a variable pattern (×20). C) PAX5 stain. Approximately 25% of cells demonstrate often faint nuclear immunoreactivity. D) Cytokeratin AE1/3 stain. Neoplastic cells are diffusely negative. There is an internal positive control of surface respiratory epithelium

Fig. 4

Subcutaneous emphysema of the right frontal region in a cat with nasal lymphoma after chemotherapy

Fig. 5

Dorsoventral (A) and right lateral (B) radiographic images of the head present lateral deviation of the right eyeball (red arrow) and subcutaneous emphysema dorsal to the skull (orange arrow). Right lateral (C) and ventrodorsal (D) radiographic images of the thorax present marked differentiation of mediastinal structures (red arrow) consistent with pneumomediastinum and multiple compartmentalized subcutaneous lucencies in overall body surfaces (orange arrows). Right lateral (E) and ventrodorsal (F) radiographic images of the abdomen also present subcutaneous emphysema (red arrows)

Fig. 6

(A) Transverse and (B) dorsal plane computed tomographic images with window settings optimized for visualizing bones. The right lacrimal bone shows lytic change (arrows). (C) 3D volume-rendering image of the right side of the skull shows bone lysis and lateral displacement of the fragmented lacrimal bone (arrow), which can be compared to (D) the normal left side. (E) Transverse plane CT with lung mode settings shows periorbital gas (arrow) and (F) marked subcutaneous emphysema (green arrows) and pneumomediastinum (yellow arrow)