¹⁸F-FDG and ¹¹C-MET positron emission tomography findings of cutaneous mast cell tumor in a dog

A 12-year-old intact male Maltese dog presented with an inguinal mass. Histopathology revealed a grade III mast cell tumor. Computed tomography demonstrated pulmonary and inguinal nodules and masses. Chemotherapy was performed using a vinblastine/prednisone protocol, and the inguinal mass disappeared 5 weeks later. Use of 2-deoxy-2-[1?F]fluoro-D-glucose (1?F-FDG) and (L)-[methyl- 11C]methionine (11C-MET)-positron emission tomography (PET) demonstrated hypermetabolic areas in the lungs and inguinal region one week after initial chemotherapy. The standardized uptake values of 1?F-FDG were not different between lung and inguinal lesions; however, the inguinal lesion had a higher 11C-MET standardized uptake value than the lung lesions. The hypermetabolic area was still visible on the second 1?F-FDG-PET scan despite the disappearance of the mass. This is the first report of 11C-MET-PET findings associated with a cutaneous mast cell tumor in a dog.     

Prognostic factors for survival of dogs with inguinal and perineal mast cell tumors treated surgically with or without adjunctive treatment: 68 cases (1994-2002)

OBJECTIVE: To determine the prognostic factors for survival and tumor recurrence in dogs with cutaneous mast cell tumors (MCTs) in the perineal and inguinal regions treated surgically with or without adjunctive radiation therapy, chemotherapy, or both. DESIGN: Retrospective study. ANIMALS: 68 dogs. PROCEDURE: Medical records of dogs with histologically confirmed MCTs in the perineal region, inguinal region, or both treated surgically with or without adjunctive radiation therapy, chemotherapy, or both were reviewed. RESULTS: Mean tumor-free interval was 1,635 days (median not reached), and 1- and 2-year tumor-free rates were 79% and 71%, respectively. Median survival time was 1,111 days (mean, 1,223 days), and 1- and 2-year survival rates were 79% and 61%, respectively. Factors that negatively influenced survival time were age at diagnosis, tumor recurrence, and treatment with lomustine. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that dogs with MCTs in the inguinal and perineal regions, if appropriately treated, may have survival times and tumor-free intervals similar to dogs with MCTs in other locations.     

High-grade myofibroblastic sarcoma of inguinal region in a dog

A subcutaneous tumor in the left inguinal region was present in an 11-year-old female bloodhound. Histopathologically, the tumor showed invasive growth and extensive necroses, and it was composed of spindle-shaped, elongated, and stellate neoplastic cells accompanied by occasional giant cells arranged in fascicular, herringbone, or irregular storiform patterns with abundant production of collagen fibers. The cytoplasm of most tumor cells was positive for vimentin, alpha-smooth muscle actin, and calponin, but was negative for desmin, smoothelin, and S-100. Furthermore, most of the tumor cells were negative for Iba1 while some tumor cells were weakly positive. Thus, this tumor was diagnosed as a high-grade myofibroblastic sarcoma according to the diagnostic criteria for human myofibroblastic sarcomas.     

Mixed germ cell-sex cord-stromal tumor with a concurrent interstitial cell tumor in a ferret

A 5-year-old male ferret presented with an enlarged canalicular testis in the left inguinal region. Microscopically, the enlarged testis consisted of a diffuse intimately admixed proliferation of c-kit-positive germ cell-like and Wilms tumor-1 protein-positive Sertoli cell-like components, but no Call-Exner body was detected. In addition, the compact proliferation of steroidogenic acute regulatory protein-intense positive interstitial cells was identified in a separate peripheral area of the mass. Based on histopathological and immunohistochemical findings, the tumor was diagnosed as a mixed germ cell-sex cord-stromal tumor with a concurrent interstitial cell tumor.     

Cystic lymphangioma in a colt.

A 6-month-old Morgan colt was examined because of preputial edema and multiple nodular masses in the left inguinal region. A tentative diagnosis of lymphatic hamartoma was made on the basis of initial biopsy findings. The prognosis for surgical excision was poor due to the progressive expansile growth of the tumor. Secondary infectious complications developed, and the colt was euthanatized at the owner's request. An abdominal and retroperitoneal mass was seen at postmortem examination. The mass was adherent to the left lumbar musculature, the craniodorsal aspect of the pelvic inlet, the midjejunum, the left testicle, and the left kidney. The mass extended through the left inguinal and femoral canals into the deep intermuscular fascia of the hindlimb. Histologic examination of the mass indicated that it was a cystic lymphangioma.     

Tumors in dwarf galagos (Galagoides demidovii)

Three spontaneously occurring tumors are described in dwarf galagos. One tumor was a subcutaneous fibrous histiocytoma in the left inguinal area of an adult male; the other two were bile duct carcinomas in a seven-year-old male and a four-year-old female. Both bile duct carcinomas had remarkable invasive and metastasizing capacities.     

Pathological Findings in a Case of Equine T-Cell Lymphoma Associated with Ataxia

A 15-year-old Dutch Warmblood gelding suddenly developed incoordination and hindlimb stumbling. The horse had a history of eyelid lymphoma. Necropsy revealed yellow-white or dark reddish-brown masses adhering to the outer surface of the spinal dura mater from the first cervical vertebra to the seventh thoracic vertebra. The spinal cord close to the first cervical vertebra and the seventh thoracic vertebra was markedly compressed by the masses filling the epidural space. The masses were also observed in the larynx, eyelids, and adipose-rich tissues, including the joints and orbits. They appeared similar in shape. The mandibular, retropharyngeal, axillary, superficial inguinal, deep inguinal, and lateral iliac lymph nodes were solid and enlarged. Histologically, the masses were composed of small or medium-sized lymphocyte-like tumor cells, but atypical cells and mitotic figures were rare. There were moderate infiltrations of macrophages and multinucleated giant cells, which were occasionally ingesting the surrounding tumor cells. Immunohistochemically, the tumor cells were classified as T-cell-derived cells. Throughout the spinal cord, enlargement or loss of nerve axons, dilation of periaxonal spaces, and macrophage infiltration into periaxonal spaces were observed, mainly in the ventral funiculus. Spinal cord compression by the tumor mass was suggested as a cause of the locomotive dysfunction. This is the first report of equine lymphoma with ataxia located from the proximal cervical to middle thoracic dura mater and in joint cavities.     

Outcome of dogs with mast cell tumors in the inguinal or perineal region versus other cutaneous locations: 124 cases (1990-2001)

OBJECTIVE: To compare clinical outcome of dogs with cutaneous mast cell tumors (MCTs) in the inguinal or perineal region with outcome for dogs with MCTs in other cutaneous locations. DESIGN: Retrospective study. ANIMALS: 37 dogs with MCTs in the inguinal or perineal region and 87 dogs with MCTs in other cutaneous locations. PROCEDURE: Information obtained from the medical records included sex, breed, age, histologic grade of all tumors, number and location of all tumors, tumor size (ie, diameter of the tumor), completeness of surgical excision, treatments administered in addition to surgery, and outcome. In all dogs, the primary treatment consisted of surgical excision. RESULTS: Disease-free interval and survival time for dogs with MCTs in the inguinal or perineal region were not significantly different from values for dogs with MCTs in other cutaneous locations. Dogs with incompletely excised tumors, dogs with grade III tumors, and dogs that received systemic treatment were 2, 2.5, and 4 times as likely, respectively, to have a relapse. Factors significantly associated with a shorter survival time were age > 8 years, metastatic disease at the time of initial diagnosis, and tumor relapse. CONCLUSIONS AND CLINICAL RELEVANCE: Results of the present study suggest that dogs with MCTs in the inguinal or perineal region do not have a worse prognosis in regard to disease-free interval or survival time than do dogs with MCTs in other cutaneous locations. Treatment recommendations for dogs with cutaneous MCTs should be based on confirmed predictors of biological behavior, such as histologic grade and clinical stage.     

Recurrent adenocarcinoma in a ferret

A 4.5-year-old, neutered male ferret with a history of recurrent adenocarcinoma in the preputial region was given 2 radiation treatment courses designed to control the rapidly growing neoplasm. The tumor regressed completely after the first 3.5-week course of therapy. The ferret remained clinically disease-free for 4 months, at which time small masses were noticed in the inguinal area and the original tumor site. A second course of therapy was administered, which again resulted in complete clinical regression of the neoplasm. However, the duration of remission was brief. Local recurrence and abdominal metastasis were observed within 2 months of the completion of therapy.     

Testicular neoplasia in the retained testicles of an intersex male dog

This case describes the presentation and management of an 8 yr old phenotypically female intersex male dog presented for evaluation of a mass in the right inguinal region. The right inguinal space was surgically explored, and a large irregular mass resembling a fully developed testicle was identified in the right vaginal tunic. A second mass resembling an atrophied, but anatomically mature testicle, was identified in the left tunic. The larger mass was identified as a Sertoli cell tumor that had replaced all normal testicular tissue. The smaller mass was identified as a testicle that contained a small intratubular seminoma. The patient was diagnosed as having a phenotypic female sex, chromosomal male sex, and a gonadal male sex. Hormone assays completed before and after the gonadectomy and mass removal document an elevation of circulating progesterone presurgically that returned to baseline by 1 mo postsurgically. The source of the progesterone was identified to be the Leydig cells of the atrophied testicle.     

Bilateral intracorporeally sutured inguinal herniorrhaphy using 3-dimensional laparoscopy in a dog

A 7-month-old, intact male, mixed breed dog with bilateral inguinal hernias underwent general anesthesia for laparoscopic bilateral inguinal herniorrhaphy via a 3-port approach. A 3-dimensional laparoscopic system was used to perform the procedure immediately following prescrotal open castration. Intracorporeal suturing with polypropylene was performed, and 2 cruciate sutures were placed to close each inguinal ring. The caudal aspect of each inguinal ring was left slightly open so as not to disrupt the passage or patency of vessels and nerves. No intra- or post-operative complications occurred. One year after surgery, the dog has no evidence of recurrence of the inguinal hernias.Key clinical message:This case report demonstrates a novel minimally invasive approach to inguinal herniorrhaphy in a dog with no reported complications and a good long-term outcome. Intracorporeally sutured inguinal herniorrhaphy is feasible in dogs with good results, although additional cases are needed to gain experience with this technique in dogs with varying presentations of inguinal hernias.     

Intracorporeal suture closure of the internal inguinal and vaginal rings in foals and horses

Objective— To report a technique for repair or prevention of inguinal hernia in horses using intracorporeal suture closure of the internal inguinal and vaginal rings.
Study Design— Case series.
Animals— Foals (n=6) and geldings (n=2).
Methods— After selection of a peri-umbilical telescope portal, instrument portals were made unilaterally or bilaterally, as needed. Herniated viscera was reduced, castration (foals) or spermatic cord remnant transection at the internal inguinal ring (adults) performed, and then simple interrupted intracorporeal sutures of synthetic absorbable suture material were used to close the internal inguinal and vaginal rings.
Results— There was no recurrence of inguinal hernia. Postoperative morbidity was minimal and cosmetic outcome was comparable to that achieved with conventional, open techniques.
Conclusion— Laparoscopic, primary closure of the internal inguinal ring by use of intracorporeal sutures provides a secure barrier to herniation and costs considerably less than using endoscopic staples.
Clinical Relevance— Laparoscopic suture closure of the internal inguinal and vaginal rings provides safe and effective repair of inguinal hernia in horses.     

Vaginal Ring and Round Ligament of the Uterus in the Female Cat

The peritoneum was examined for the existence of a vaginal ring and the round ligament of the uterus was dissected through the inguinal region in eleven embalmed adult female cats. In all cats, there was no evidence of a peritoneal evagination into the inguinal canal. There was no vaginal ring and no vaginal process. The round ligament of the uterus passed through the inguinal canal and disintegrated in the fascia a short distance beyond the superficial inguinal ring.     

Use of an inguinal approach adapted from equine surgery for cryptorchidectomy in dogs and cats: 26 cases (1999-2010)

OBJECTIVE-To determine whether a surgical technique used in cryptorchid horses can be used successfully to remove testicles retained in the inguinal region or abdominal cavity in dogs and cats. DESIGN-Retrospective case series. ANIMALS-22 dogs and 4 cats with cryptorchidism. PROCEDURES-In 1999 through 2010, 26 cryptorchid patients underwent surgery during which an incision was made over the inguinal ring and the undescended testicle was located for removal via identification of the vaginal process and the embryonic gubernaculum. Castration was performed once a testicle was located in the inguinal region or via removal of an intra-abdominally located testicle through the inguinal canal. RESULTS-4 dogs and 1 cat were bilaterally cryptorchid. Testicles were retained in the abdominal cavity in 18 dogs and in the inguinal region in 4 dogs; in all 4 cats, undescended testicles were located in the inguinal region. Twenty-one dogs and 4 cats were castrated without breaching the abdominal cavity; in one of those dogs, the inguinal ring was enlarged to permit extraction of a tumorous testicle. In 1 dog, the inguinal ring was enlarged into a paramedian laparotomy and viscera were manipulated to exteriorize an intra-abdominally located testicle because the gubernaculum had ruptured. Major intraoperative or long-term complications did not occur. CONCLUSIONS AND CLINICAL RELEVANCE-Results suggested that as in horses, the surgical approach over the inguinal ring, wherein the vaginal process and the remnant of the gubernaculum are identified and used to locate an undescended testicle for removal, can be used successfully in dogs and cats.     

Noninvasive Inguinal Approach for Cryptorchidectomy in Thirty-eight Stallions

We describe the results of the noninvasive inguinal approach in 38 cases of cryptorchidism. Whether the retained testis was intra-abdominal or in the inguinal canal, this technique was found to be an easy, reliable method of locating abdominal and inguinal testes through a normal body opening. No postoperative complications were recorded in this series of cases and the postoperative rest period was minimal.     

Pyometra with inguinal herniation of the left uterine horn and omentum in a Beagle dog

Objective: To describe a unique case of pyometra with inguinal herniation of the left uterine horn and omentum. Case summary: A 7‐year‐old, 19 kg, intact female Beagle dog presented for surgical treatment of presumptive pyometra and biopsy of a caudal abdominal mass in the left inguinal mammary gland region. Ventral midline celiotomy was performed, and a distended, fluid‐filled uterus with passage of the distal aspect of the left uterine horn through the left vaginal process into the inguinal canal was identified. The patient recovered uneventfully following ovariohysterectomy and left inguinal herniorrhaphy. New or unique information provided: This is the first documented report of inguinal herniation of a uterine horn associated with a pyometra.     

Inguinal enterocutaneous fistula in a dog

A two‐year‐old Jack Russell terrier presented with a chronic history of weight loss and the recent development of a discharging wound in the left inguinal region that was confirmed by ultrasound and contrast radiography to be an enterocutaneous fistula. One day following admission the dog displayed signs of abdominal pain and the general condition deteriorated. At exploratory coeliotomy there was evidence of septic peritonitis and a segment of jejunum was found firmly adhered to the left inguinal canal. The affected jejunal segment was excised and an end‐to‐end anastomosis performed. A penrose drain was placed in the inguinal wound which was subsequently managed with open drainage. The inguinal wound healed successfully by second intention and the dog returned to normal body condition. The left testis became atrophic and castration was performed several weeks later. To the authors’ knowledge this is the first veterinary case report of an inguinal enterocutaneous fistula.     

Herniation of the urinary bladder through a congenitally enlarged inguinal canal in a cat

A two-year-old, castrated male Main Coon cat was referred because of chronic, recurrent pollakiuria, haematuria, and acute vomiting. On clinical examination, a smooth, soft-tissue mass, suspected to be the urinary bladder, was palpable outside of the abdominal wall in the inguinal area. On radiographs, the urinary bladder was found to be extra-abdominal, and herniated through an enlarged right inguinal canal at exploratory coeliotomy.The left inguinal canal was also enlarged. The urinary bladder was repositioned and fixed to the caudal abdominal wall by incisional cystopexy and both enlarged inguinal canals were partially closed with an interrupted suture pattern.     

Inguinal herniation with hydrometra/mucometra in a poodle bitch

A 5-year-old, sexually intact poodle bitch was presented with a 2-year history of inguinal mass. A tentative diagnosis of hydrometra/mucometra with inguinal herniation was made and ovariohysterectomy with hernia repair was performed. Both fluid-filled uterine horns, both broad ligaments, and the uterine body were observed to be herniated through the inguinal ring. On histopathology, marked edema and diffuse hemorrhage were diagnosed in the uterus.     

FAT NECROSIS SIMULATING RECURRENT NEOPLASIA FOLLOWING EXTERNAL BEAM RADIOTHERAPY IN A DOG

A 4.5-year-old neutered male dog was diagnosed with incompletely excised well-differentiated lymphangiosarcoma in the right inguinal subcutaneous region. The mass had metastasized to the right hypogastric and medial iliac lymph nodes. Surgery followed by definitive radiation therapy was administered to the primary site and the sites of metastasis. The dog had a complete response to radiotherapy, and minimal acute side effects. Doxorubicin was administered after radiotherapy. Approximately 4 months following radiation therapy, the dog developed a mass, presumed recurrent tumor, in the original site. In a biopsy only steatitis and fibrosis were found. The mass continued to grow and conservative surgical excision was elected. Histopathologically the diagnosis was fat necrosis and steatitis, with a microscopic focus of lymphangiosarcoma. Fat necrosis is an uncommon sequelum to breast irradiation in people and also appears to be rare in animals. Fat necrosis should be considered as a differential diagnosis when recurrent tumor is suspected in a previously irradiated subcutaneous site in a dog.