Median lingual hair heterotopia associated with pyogranulomatous glossitis in a Labrador retriever: Surgical treatment using carbon-dioxide laser.

A 9-year-old male Labrador retriever dog was presented with dysphagia and presence of hairs on the tongue. Buccal examination revealed ulcerative glossitis and lingual hairs along the midline. Ultrasound and magnetic resonance imaging of the tongue showed multiple hair shafts contained in a proliferative tissue along the midline and extending in a fistulous tract towards the right ventral aspect of the tongue at mid-length. Surgical excision was completed using a carbon-dioxide laser. Histopathological examination revealed a pyogranulomatous inflammation centered on growing hairs, confirming the diagnosis of glossitis and lingual hair heterotopia. At 10 mo after surgery, all clinical signs and glossitis had disappeared despite partial recurrence of hair on the dorsal sulcus and in the sublingual fistula. Key clinical message: Although lingual hair heterotopia usually has no clinical repercussions, associated ulcerative lesions should support imaging and biopsy.Resection of the lesion using a carbon-dioxide laser resulted in a good outcome in this case, but recurrent hair growth is possible.

Hétérotopie pilaire linguale associée à une glossite pyogranulomateuse chez un chien labrador : traitement chirurgical à l'aide d'un laser au dioxyde de carbone. Un chien Labrador mâle entier de 9 ans est présenté pour une dysphagie et la présence de poils sur la langue. L'examen de la cavité buccale met en évidence une glossite sévère associée à des implantations pilaires. L'échographie et l'imagerie par résonance magnétique de la langue mettent en évidence de multiples poils contenus dans du matériel tissulaire s'étendant le long de la ligne médiane et présentant un trajet fistuleux vers la partie ventrale droite de la langue à mi-longueur de cette dernière. Une exérèse est réalisée à l'aide d'un laser au dioxyde de carbone. L'examen histopathologique de la pièce d'exérèse révèle une inflammation pyogranulomateuse centrée sur des poils en croissance, confirmant le diagnostic de glossite et d'hétérotopie pilaire linguale. Dix mois après la chirurgie, aucun signe clinique n'est réapparu et la glossite a disparu, malgré la récidive partielle de poils sur la partie dorsale de la langue et en région sublinguale droite.Message clinique clé : Bien que l'hétérotopie pilaire linguale n'ait généralement pas de répercussion clinique, les lésions ulcéreuses associées devraient justifier une imagerie et une biopsie.La résection de la lésion à l'aide d'un laser au dioxyde de carbone a donné de bons résultats dans ce cas, mais une pousse récurrente des poils est possible.(Traduit par les auteurs).

Myopathy with oval inclusions in a domestic shorthair cat.

Case summary: An 18-month-old castrated male domestic shorthair cat was presented with a 2-month history of collapse and severe weakness, particularly affecting the pelvic limbs. A biceps femoris muscle biopsy revealed excessive variability in myofibre size, mild necrosis, minimal centronucleation and scattered 10 µm intracytoplasmic oval inclusions. The inclusions appeared amphophilic with haematoxylin and eosin, blue with Gomori trichrome and unstained with nicotinamide adenine dinucleotide dehydrogenase tetrazolium reductase staining. ATPase staining revealed a normal mosaic pattern and atrophy of both type 1 and 2 myofibres. The pathological diagnosis was a myopathy with inclusions. In contrast to previous feline myofibre inclusions previously reported in the literature, inclusions were not identified after immunohistochemistry using anti-desmin, tubulin, spectrin, laminin, LAMP and LC3 antibodies. After supportive care and corticosteroid treatment, clinical improvement was noted and the cat was discharged 10 days after initial presentation. Clinical and neurological re-examinations were performed at 1, 3, 6 and 9 months after discharge. Owner contact at both 10 and 30 months post-discharge confirmed that persistent muscular weakness was present. Relevance and novel information: This case report describes a novel and slowly progressive feline myopathy associated with oval amphophilic inclusions unreactive to immunostaining, which have not been previously reported in feline myopathies.

Satellite cells fail to contribute to muscle repair but are functional in Pompe disease (glycogenosis type II).

Pompe disease, which is due to acid alpha-glucosidase deficiency, is characterized by skeletal muscle dysfunction attributed to the accumulation of glycogen-filled lysosomes and autophagic buildup. Despite the extensive tissue damages, a failure of satellite cell (SC) activation and lack of muscle regeneration have been reported in patients. However, the origin of this defective program is unknown. Additionally, whether these deficits occur gradually over the disease course is unclear. Using a longitudinal pathophysiological study of two muscles in a Pompe mouse model, here, we report that the enzymatic defect results in a premature saturating glycogen overload and a high number of enlarged lysosomes. The muscles gradually display profound remodeling as the number of autophagic vesicles, centronucleated fibers, and split fibers increases and larger fibers are lost. Only a few regenerated fibers were observed regardless of age, although the SC pool was preserved. Except for the early age, during which higher numbers of activated SCs and myoblasts were observed, no myogenic commitment was observed in response to the damage. Following in vivo injury, we established that muscle retains regenerative potential, demonstrating that the failure of SC participation in repair is related to an activation signal defect. Altogether, our findings provide new insight into the pathophysiology of Pompe disease and highlight that the activation signal defect of SCs compromises muscle repair, which could be related to the abnormal energetic supply following autophagic flux impairment.