Tracheal and Colonic Resection and Anastomosis in a Boa Constrictor (Boa constrictor) with T-Cell Lymphoma
An eight-year-old, female intact, boa constrictor (Boa constrictor) was presented for a 1.5- month history of wheezing, open-mouth breathing, and hyperextension of the neck. Radiographs, ultrasound (US), computed tomography (CT), and tracheal endoscopy revealed an intra- and extraluminal tracheal mass occluding approximately 95% of the tracheal lumen. Complete blood count and biochemistry panel were unremarkable, except for a moderate elevation of the hematocrit. A caudal saccular lung cannulation was placed as an emergency procedure because of worsening respiratory distress. Resection of 22 tracheal rings, inclusive of the mass, followed by anastomosis of the trachea was performed. Histopathology, immunohistochemistry, and electronic microscopy (EM) were consistent with a tracheal round cell neoplasia. Eleven months after the initial surgery, the snake presented for a caudal coelomic mass associated with constipation. Radiographs, US and CT findings were consistent with an infiltrating circumferential colonic mass, which was surgically resected. Histopathology and EM confirmed a round cell tumor that was morphologically identical to the previous tracheal tumor. In addition, cytoplasmic eosinophilic inclusions, consistent with subclinical Inclusion Body Disease (IBD), were noticed in the colonic mass. Eleven weeks after the second surgery, recurrence of the mass was observed in the colonic surgical area. A single L-asparaginase injection was attempted as a palliative treatment, and was unsuccessful. As the snake's condition declined, euthanasia was elected. Necropsy confirmed multiple malignant T-cell lymphoma in the esophagus, stomach, and colon. This is the first report of a tracheal and digestive tract malignant T-cell lymphoma in a boa. Surgical management of this case provided a palliative treatment for a life-threatening disease and a survival time of 14 months from initial presentation. Also, this is the third case report of a lymphoma in a boa with a concurrent IBD.Abstract
(A) Right lateral radiograph of the tracheal region of an 8-year-old boa constrictor (Boa constrictor). A round, soft-tissue mass (black arrow) is invading the tracheal lumen at the level of the mid-trachea, cranial to the heart (asterisk). (B) and (C) Transverse computed tomography images of the cervical area of a boa constrictor in a lung algorithm (B) and soft-tissue algorithm (C) revealed a soft tissue mass partially obstructing the tracheal lumen (white asterisk). The mass extends ventrally and medially beyond the tracheal wall (white arrow), close to the esophagus (black arrow). A rubber tube has been inserted into the esophagus to delineate this structure during image acquisition (black arrow). The black asterisk indicates the cervical vertebrae.
Portion of the trachea of a boa constrictor before (A) and after (B) longitudinal section, showing an extra- and intramural round, tan and firm mass, partially obstructing the tracheal lumen. Histologic examination of the tracheal mass (H&E, C) 10 × magnification, (D) × 40 magnification revealed poorly differentiated round cells with a moderate amount of vacuolated, amphophilic cytoplasm and round to oval nuclei. Mitotic figures were rare and the mass was infiltrated by moderate numbers of granulocytes.
Tracheoscopy before (A) and 35 weeks after (B) tracheostomy and tracheal anastomosis. The tracheoscopy before surgery revealed an irregular pale mass almost completely obstructing the tracheal lumen. Tracheoscopy postsurgery revealed no mass regrowth at the area of the resection and anastomosis and showed a mildly inflamed tracheal mucosa with approximately 10% reduction of the tracheal lumen and minimal suture granuloma formation.
(A) Dorsal plane reconstruction of contrast enhanced computed tomography of the caudal coelom of a boa constrictor. A contrast enhancing, soft tissue attenuating, mural, colonic mass is present. The cranial and caudal extent of this mass is indicated by the white “X”. Mineral attenuating stool is present within the colon cranial to the mass, indicated by the arrow. (B) Transverse plane contrast enhanced CT of the caudal coelom. The colonic mass is filling the majority of the cross-sectional area of the coelom at this level. The dorsal and ventral borders of this mass are indicated by the white circles. The borders of the lumen of the colon are indicated by the white “X”. (C) Transverse plane ultrasound image of the caudal coelom using a 5–8 MHz microconvex transducer. The dorsal and ventral borders of the colonic mass are indicated by the white circles. The borders of the lumen of the colon are indicated by the white “X”.
(A) Intraoperative photographs of the colonic mass, left lateral approach. The affected portion has been freed from the mesenteric attachment. The two Penrose drains delimitate the portion of the colon cranial and distal to the mass. (B) Histologic examination of the resected colonic mass revealed similar characteristics to the tracheal mass (H&E, magnification × 10).
Necropsy gross examination. The digestive tract has been incised along the longitudinal axis. Two pale tan masses expand the wall of the esophagus (black asterisk) and stomach (white asterisk).
