Epidermal Collarette Research Articles

Epithelioid Fibrous Histiocytoma Is on a Continuum With Superficial ALK-rearranged Myxoid Spindle Cell Neoplasm: A Clinicopathologic Series of 35 Cases Including Alternate RET and NTRK3 Fusions.

Anaplastic lymphoma kinase (ALK) rearrangements drive most examples of epithelioid fibrous histiocytoma (EFH) and have been reported in an emerging family of receptor tyrosine kinase (RTK) fusion-positive mesenchymal neoplasms, including superficial ones described under the rubric of "superficial ALK-rearranged myxoid spindle cell neoplasm" (SAMS). Here, we describe 35 superficial tumors with SAMS morphology, which occurred in 18 females (51%) and 17 males at a median age at presentation of 39 years (range: 6 to 82y). Most tumors occurred on the lower extremity (25 tumors; 71%), followed by upper extremity (5; 14%), trunk (3; 9%), and face (2; 6%). Nine tumors were reported to have grown slowly before presentation, including >10 years in 2 cases. Tumors occurred primarily in the dermis (32 tumors; 91%) or subcutis (3; 9%); 8 dermal tumors extended into the subcutis. Median tumor size was 1.3cm (range: 0.5 to 8.0cm). Clinical follow-up was available for 12 patients (34%; range: 2mo to 21y; median: 2.7y), none of whom experienced metastasis. One incompletely resected tumor recurred locally at 19 months, and no other patients experienced recurrence. Histologically, tumors were characterized by bland spindle-to-ovoid cells showing whorled growth and myxoid-to-collagenous stroma. Recurrent features included an epidermal collarette (19/30; 63%), perivascular hyalinization (20/35; 57%), amianthoid collagen (14/35; 40%), and metaplastic ossification (2/35; 6%). Immunohistochemistry (IHC) demonstrated expression of ALK (24/31; 77%), CD34 (15/21; 71%), EMA (17/28; 61%), and S-100 (9/32; 28%). Eleven tumors showed hybrid morphologic features between EFH and SAMS; 9 of them (82%) showed cytomorphology typical of EFH but with whorled growth, myxoid stroma, and/or regions of spindle cell morphology. Two hybrid tumors showed sharp transitions between a region characteristic of EFH and a region characteristic of SAMS, with a concomitant sharp transition in EMA, CD34, and S-100 expression by IHC. Sequencing revealed ALK fusions in 15 of 19 tumors: 2 each with fusion partners FLNA, SQSTM1, and VCL, and 1 each with COL1A2, DCTN1, EML4, FXR1, MPRIP, PLEKHH2, PRKAR1A, SPECC1L, and TLN2. Thirteen of 14 ALK-rearranged tumors expressed ALK by IHC. Three tumors negative for ALK fusions instead harbored alternate RTK fusions (NCOA4::RET, TRIM27::RET, and VIM::NTRK3), and 1 tumor was negative for RTK alterations. CDKN2A/B deletions were found in 2 tumors with ALK fusions and both tumors with RET fusions. SAMS is on a morphologic and molecular genetic spectrum with EFH, with a similar body site distribution, frequent clinical presentation as an exophytic skin tumor, and invariably benign outcomes; we conclude that SAMS should be considered a histologic variant of EFH. Some morphologically typical examples harbor alternate RET and NTRK3 fusions, such that SAMS is not an appropriate designation for this morphologic class; instead, to highlight the clinicopathologic similarities to EFH, we propose the diagnostic term "myxoid spindle cell variant of epithelioid fibrous histiocytoma."

Translated article] Clear Cell Acanthoma: A Series of 70 Cases

Background and objectiveClear cell acanthoma (CCA) is an uncommon lesion histologically characterized by the presence of epidermal acanthosis with keratinocytes containing clear cytoplasm. Although many single cases of CCA have been described, few case series have been published. The aim of this study was to describe the clinical characteristics of CCA in our practice setting. Material and methodsRetrospective study of patients diagnosed with CCA at Hospital Universitario de Bellvitge in Barcelona, Spain, between 1995 and 2021. We conducted a chart review to record age, sex, number and location of lesions, diameter, time since onset, clinical characteristics, suspected clinical diagnosis, and treatment. ResultsSeventy patients (30 women and 40 men) with a mean (SD) age of 62 (13) years were diagnosed with CCA during the study period. Median (interquartile range) time since onset was 2 (4) years and median lesion diameter was 6 (5)mm. One woman had multiple lesions. Lesions were located on the lower extremities in 57 patients (81%), the posterior aspect of the trunk in 8 (11%), the anterior aspect of the trunk in 4 (5%), and the upper extremities in 1 (1%). CCA was clinically suspected in 40% of patients seen by dermatologists. ConclusionsCCA presents as an erythematous, dome-shaped lesion with pinpoint vessels and an epidermal collarette. The accuracy of clinical diagnosis has improved relative to earlier series, possibly due to a better clinical understanding of this lesion and a greater use of dermoscopy.

Acantoma de células claras. Estudio clínico de 70 pacientes

Background and objectiveClear cell acanthoma (CCA) is an uncommon lesion histologically characterized by the presence of epidermal acanthosis with keratinocytes containing clear cytoplasm. Although many single cases of CCA have been described, few case series have been published. The aim of this study was to describe the clinical characteristics of CCA in our practice setting. Material and methodsRetrospective study of patients diagnosed with CCA at Hospital Universitario de Bellvitge in Barcelona, Spain, between 1995 and 2021. We conducted a chart review to record age, sex, number and location of lesions, diameter, time since onset, clinical characteristics, suspected clinical diagnosis, and treatment. ResultsSeventy patients (30 women and 40 men) with a mean (SD) age of 62 (13) years were diagnosed with CCA during the study period. Median (interquartile range) time since onset was 2 (4) years and median lesion diameter was 6 (5) mm. One woman had multiple lesions. Lesions were located on the lower extremities in 57 patients (81%), the posterior aspect of the trunk in 8 (11%), the anterior aspect of the trunk in 4 (5%), and the upper extremities in 1 (1%). CCA was clinically suspected in 40% of patients seen by dermatologists. ConclusionsCCA presents as an erythematous, dome-shaped lesion with pinpoint vessels and an epidermal collarette. The accuracy of clinical diagnosis has improved relative to earlier series, possibly due to a better clinical understanding of this lesion and a greater use of dermoscopy.

A sessile nodule with vascular appearance

A 78-year-old man presented with a 4-month history of a progressively growing, bleeding, elevated sessile nodule, located in his right upper extremity (Fig 1). Polarized light noncontact dermoscopy revealed that the lesion had a vascular appearance (Fig 2). No previous trauma, arthropod bites, or systemic manifestations were reported. No regional lymphadenopathies were spotted. The histologic examination showed an exophytic proliferation, sharply circumscribed to papillary dermis, and a discrete epidermal collarette.

Analyzing the morphological spectrum of epithelioid fibrous histiocytoma and the immunohistochemical performance of the ALK D5F3 and ALK1 clones

Epithelioid fibrous histiocytoma (EFH) is a cutaneous neoplasm driven by translocations of the anaplastic lymphoma kinase (ALK) gene, which can be demonstrated by immunohistochemical (IHC) analysis. We analyzed the performance of two ALK clones, D5F3 and ALK1, in a cohort of EFHs and described the range of architectural variation of these lesions. TFE3 IHC was performed in ALK-negative EFHs. We identified 21 cases of EFH, 76.2% of which showed an exophytic appearance and 19% displayed flat architecture. A well-developed epidermal collarette was present in 48% of all cases with just more than a third of all the exophytic lesions presenting as dermal-based nodules. ALK D5F3 expression was identified in 76.2% (16/21) of all cases, but only 68.8% were concordantly positive with the ALK1 clone, indicative of a false-negative stain with ALK1 in 31.2% of the cases. For the subset of cases showing positivity for the ALK1 clone, a marked decrease in the percentage of immunolabelled cells was identified when compared with D5F3 (5-50% vs. 100%, respectively). Five cases (23.8%) did not demonstrate ALK expression for either clone, with 3 of those cases showing nuclear positivity for TFE3 IHCand the remaining 2 cases being double negative (ALK-/TFE3-). In summary, we identified that the prototypically described exophytic appearance with epidermal collarette is present in only less than half of the cases. We also demonstrated that the ALK1 antibody is suboptimal in EFH and should not be utilized in this setting. A subset of ALK-negative cases express TFE3, but double-negative cases occur.

Complete Genome Sequences of Six Staphylococcus pseudintermedius Strains from Dogs with Superficial Pyoderma in Georgia, USA.

ABSTRACTStaphylococcus pseudintermedius is a pathogen of veterinary importance, as it is the major causative agent of superficial pyoderma in dogs. We present the complete genome sequences of six strains of S. pseudintermedius derived from dogs affected with epidermal collarettes and superficial bacterial folliculitis, which are two variants of superficial pyoderma.

Pyogenic granuloma-like Kaposi sarcoma: Case report and review of literature

Pyogenic granuloma-like Kaposi sarcoma (PGLKS) is an uncommon variant of Kaposi sarcoma (KS), which mimics benign pyogenic granuloma both clinically and histologically. We report a case of PGLKS of the toe occurring in a HIV-positive individual. It presented as a 2cm skin swelling of 2 weeks’ duration which was clinically felt to be a pyogenic granuloma. Histopathological examination revealed a polypoid atypical vascular lesion with overlying peripheral epidermal collarette. Spindle cell proliferation typically seen in KS was also identified, which was positive for human herpesvirus 8 (HHV8) by immunohistochemistry, confirming the diagnosis of PGLKS. Upon review of the literature, our case is the 29th case of PGLKS reported to date, and only the sixth in Asian population. Particular attention to histomorphology, and demonstration of HHV8 in lesional tissue will aid accurate diagnosis of this rare entity.

Characterization of Cutaneous Bacterial Microbiota from Superficial Pyoderma Forms in Atopic Dogs

Although Staphylococcus pseudintermedius is considered the major pathogen associated with superficial canine pyoderma, no study has investigated the entire bacterial community in these lesions with molecular techniques. The objectives of this study were to characterize the bacterial microbiota in two forms of superficial canine pyoderma lesions, superficial bacterial folliculitis (SBF) and epidermal collarette (EC), especially in terms of the staphylococcal community. Swabs from 12 SBF and 9 EC lesions were obtained from eight and six atopic dogs, respectively. Eight samples from the axilla and groin of four healthy dogs served as controls. DNA was extracted for 16S rRNA gene sequencing and quantitative polymerase chain reaction of Staphylococcus spp. and S. pseudintermedius. Healthy skin samples harbored significantly more diverse bacterial communities than pyoderma samples. Healthy samples had communities that were more similar to each other, and were distinct from pyoderma samples. Staphylococcus spp. abundance was increased in pyoderma samples, especially those from EC samples. Although determining species-level identities of staphylococcal sequences revealed many species, S. pseudintermedius was the primary staphylococcal species found in all sample types. As expected, there are many differences in the microbiota when comparing healthy and canine pyoderma lesions samples. These lesions do not seem to be associated with a change in the relative abundance of specific Staphylococcus species, but simply an overall increase in Staphylococcus spp. abundance. The results of this study provide a starting point for future studies investigating how antimicrobial treatments may further change the microbiota associated with these lesions.

Can pyoderma in dogs be treated with fewer antibiotics?

Staphylococcal skin infections, generally referred to as pyoderma, are a very common reason for the prescription of antimicrobials for pet dogs.1-3 These infections, usually involving Staphylococcus pseudintermedius , vary in...

Canine pemphigus folliaceus: report of five clinical case

Pemphigus folliaceus (PF), which is considered the most common autoimmune skin disease in the dog, is associated with the formation of autoantibodies directed against the desmosomes of the upper third of the epidermis, that result in loss of keratinocyte adhesion (acantholysis) and subsequent epidermal cleft formation. The clinical and histopathological findings, along with the response to treatment in 5 PF cases, either idiopathic (3/5) or secondary to trimethoprim-sulfonamides (1/5) and to allergic dermatitis (1/5), are presented and discussed, accordingly. All the 5 dogs exhibited hypotrichosis-alopecia (4/5), erythema (4/5), vesicles (1/5), pustules (5/5), crusts (5/5), epidermal collarettes (3/5), excoriations (1/5), erosions (3/5), ulcers (1/5), fissures (1/5), lichenification, thickening and folding of the skin (1/5), and footpad hyperkeratosis (1/5), that were pruritic in 3 of them. These lesions were located on the head (4/5), pinnae (4/5), limbs (3/5), body trunk (3/5) and the footpads (2/5). Diagnosis was based on the results of lesionai histopathology where the most striking finding was the presence of subcorneal pustules filled with normally looking neutrophils and acanthocytes. Moreover, pustule or crust cytology that was carried out in 3 cases, revealed clusters of acantholytic cells in 2 dogs. The treatment, that was instituted in 2/5 dogs and resulted in a complete resolution of skin lesions, was based on prednisolone in immunosuppressive dosage along with azathioprine (PF secondary to allergic dermatitis), or on a combination of dapsone, Oxytetracycline and vitamin E (idiopathic PF). The remaining 3 cases were left untreated, because one showed a spontaneous remission following withdrawal of the offending medication and the other 2 were lost to follow-up.

Brown Shadow in Lichen Nitidus: A Dermoscopic Marker!

A 35-year-old male presented with asymptomatic multiple papular lesions over both forearms. Physical examination revealed multiple white-colored, flat-topped papules [Figure 1]. Based on the characteristic morphology of the lesions, a clinical diagnosis of lichen nitidus was established.Figure 1: Multiple white-colored flat-topped papules distributed bilaterally over forearmsDermoscopy (DermLite III; 3Gen; Polarized, 10×) of the lesions revealed multiple, white, well-circumscribed circular areas, 1–2 mm in diameter with a smooth surface [Figure 2a]. An indistinct brown shadow was reflected through each of these white circles [Figure 2b].Figure 2: (a) Dermoscopy demonstrates multiple, white, well-circumscribed, circular areas with a smooth surface along with an indistinct brown shadow reflected through these white circles (b) Magnified dermoscopic image of (a) demonstrating the brown shadow (black arrow) (DermLite III; 3Gen; Polarized, 10×)Histopathology revealed a circumscribed subepidermal dense focal lymphohistiocytic infiltrate along with occasional Langhans giant cells, flanked by collarettes of epidermal acanthosis on either side, which gave a “ball-in-clutch” appearance confirming the diagnosis of lichen nitidus. The overlying epidermis showed evidence of acanthosis and focal parakeratosis [Figure 3].Figure 3: Histopathology shows subepidermal foci of lymphohistiocytic infiltrate, encircled by acanthotic epidermal collarettes with parakeratosis of overlying stratum corneum (H and E stain 10×)The presence of multiple well-demarcated white circles on dermoscopy are known to correspond to epidermal acanthosis on histopathology.[12] An interesting observation made was the presence of a brownish shadow inside each of these white circles, which is in fact a reflection of the underlying dense foci of lymphocytes and epithelioid cells in the dermal papilla. This deduction concurs with the observation of the “peripilar sign” in cases of early androgenetic alopecia, wherein the superficial perifollicular lymphocytic infiltrate is seen as a brown halo around the hair follicles.[34] Hence, in lichen nitidus, the epidermal acanthosis corresponds to white circles and the central brownish shadow reflected through the white circles corresponds to the inflammatory infiltrate enveloped by the acanthotic rete ridges. This particular finding on dermoscopy establishes a strong dermoscopic and histopathological correlation in lichen nitidus, which enables us to differentiate it from other conditions mimicking it, such as pityriasis versicolor and lichen sclerosus et atrophicus. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Clinical Manifestations Enticed in Clinical Cases of Canine Pyoderma

Canine pyoderma is one of the most common causes of dermatitis with worldwide occurrence in small animal practice. The condition is diagnosed on the basis of clinical manifestations, isolation and identification of causative organisms by bacteriological cultural examination. A study was conducted on 130 dogs diagnosed with canine pyoderma presented at the Veterinary Clinical Complex (VCC), Veterinary College, Anand. These included cases of surface pyoderma (15), superficial pyoderma (50), deep pyoderma (32) and secondary pyoderma (33). The common clinical manifestations observed were exudation of pus, pruritus, erythema, pustules, papules, crusts, epidermal collarettes and alopecia. Canine pyoderma found secondary to other dermatological afflictions illustrated manifestations associated with the underlying cause. Hence, the condition should be differentially diagnosed and treated accordingly.

Pemphigus-like Drug Reaction after Surgical Removal of a Splenic Hemangiosarcoma in a Dog

A 7-year-old spayed female Shih-tzu dog with 4-month history of anorexia and weight loss was diagnosed with splenic hemangiosarcoma. One week after splenectomy, the dog developed severe, multifocal, coalescing erosive and ulcerative dermatosis with epidermal collarettes and crusts on the dorsal trunk. The dog was prescribed systemic antibiotics comprising cephradine and enrofloxacin postoperatively. Histopathological examination of skin biopsies from haired skin lesions revealed changes consistent with pemphigus foliaceus (PF). Tentative diagnosis for this patient was pemphigus-like drug reaction resulting from cephradine treatment. However, given the dog’s history of hemangiosarcoma, paraneoplastic pemphigus (PNP), a rarely reported cancer-related pemphigus in dogs, was also considered for tentative diagnosis. Significant clinical remission of dermal lesions was achieved with four weeks of prednisolone and mycophenolate mofetil (MMF) treatment. Drugs were gradually tapered and eventually discontinued with concurrent reduction of dermal lesions, and no further recurrence was noted.

Clinical, microscopic and microbial characterization of exfoliative superficial pyoderma-associated epidermal collarettes in dogs.

The microscopic and microbial features of the spreading epidermal collarettes of canine exfoliative superficial pyodermas are poorly characterized. To characterize the clinical, cytological, microbial and histopathological features of epidermal collarettes in five dogs. Cytology from the margins of collarettes identified neutrophils, extracellular and intracellular cocci within neutrophils but no acantholytic keratinocytes. Phenotypic and genotypic analyses identified all bacterial isolates from the centre and margin of five epidermal collarettes as Staphylococcus pseudintermedius. PCRs of collarette-associated Staphylococcus strains did not amplify genes encoding for the known exfoliative toxins expA and expB, whereas the predicted siet and speta amplification products were detected in all isolates. Microscopically, epidermal collarettes consisted of interfollicular, epidermal spongiotic pustules. Advancing edges of lesions consisted of peripheral intracorneal clefts in the deep stratum disjunctum above an intact stratum compactum; they contained lytic neutrophil debris, bacterial cocci and fluid, but no acantholytic keratinocytes. This intracorneal location of bacteria was confirmed using Gram stains and fluorescent in situ hybridization with eubacterial- and Staphylococcus-specific probes. The indirect immunofluorescence staining patterns of desmoglein-1, desmocollin-1, claudin-1, E-cadherin and corneodesmosin were discontinuous and patchy in areas of spongiotic pustules, whereas only that of corneodesmosin was weaker and patchy in advancing collarette edges. Epidermal collarettes represent unique clinical and histological lesions of exfoliative superficial pyodermas that are distinct from those of impetigo and superficial bacterial folliculitis. The characterization of possible causative staphylococcal exfoliatin proteases and the role of corneodesmosin in collarette pathogenesis deserve further investigation.

Alterações dermatológicas em cães com hiperadrenocorticismo – estudo retrospectivo

Skin disorders are among the major clinical changes due to chronic hypercortisolism, which results from hyperadrenocorticism of Cushing’s syndrome. The aim of our study was to identify the most common skin disorders in 22 dogs (15 females and six males, mean age = 10 years) that were referred to a Veterinary School Hospital in São Paulo, SP, within a 24-month period, presenting pituitary-dependent or adrenal-dependent hyperadrenocorticism. Cutaneous injuries were identified in 72.72% of cases. The most frequent changes were related to the presence of meliceric crusting, hair loss, erythema, comedo, epidermal collarette, hyperpigmentation, scales, pustules and papules. The dermatological diseases related with hypercortisolism were pyodermitis, demodicosis and calcinosis cutis.

First report of a mecA-positive multidrug-resistant Staphylococcus pseudintermedius isolated from a dog in New Zealand

CASE HISTORY: A 14-year-old neutered male Sealyham terrier was referred for assessment of a persistent pyoderma. It had experienced numerous episodes of dermatitis involving pododermatitis, pyoderma and otitis over the previous 6 years.CLINICAL FINDINGS: Superficial, focally deep and mucocutaneous pyoderma were present, with yellow mucoid exudate on both nares and the lower lips crusted with haemopurulent exudate. Epidermal collarettes were present on the dorsal and lateral trunk. There were peri-anal crusts and mild erythema was present on the concave aspect of both pinnae.MICROBIOLOGICAL FINDINGS: Culture and microbiological testing identified Staphylococcus pseudintermedius as the infecting organism. Kirby-Bauer disc susceptibility testing revealed the isolate was resistant to numerous antimicrobials including oxacillin. PCR testing of the isolate identified the presence of the mecA gene which confers resistance to β-lactam antimicrobials. Pulsed field gel electrophoresis typing suggested the isolate was not related to the methicillin-resistant S. pseudintermedius that had been reported to be associated with canine infections in Western Australia.DIAGNOSIS: Superficial, deep and mucus membrane pyoderma associated with a multi-drug resistant S. pseudintermedius.CLINICAL RELEVANCE: This is the first recorded case of canine pyoderma involving methicillin-resistant multidrug-resistant S. pseudintermedius in New Zealand. Treatment of such cases is difficult because the number of effective and available antimicrobials is limited. This finding should raise the awareness of the veterinary and medical professions to the presence of such organisms in New Zealand and stimulate a discussion about possible biosecurity barriers, treatment strategies and prevention of zoonotic and nosocomial infections.

Diagnostic Pitfalls of Differentiating Cellular Digital Fibroma from Superficial Acral Fibromyxoma.

Dear Editor: Acquired digital fibrokeratoma is an exophytic tumor with hyperkeratotic epidermis on acral sites. Meanwhile, cellular digital fibroma (CDF) is a unique subset of acquired digital fibrokeratomas that comprise slender spindle-shaped CD34-positive cells1. Here, we report a rare case of CDF and its clinicopathologic characteristics. A 38-year-old Korean man presented with a painless nodule, which began to grow six months prior to examination, on the ventral part of the proximal phalanx of his right index finger. Physical examination revealed a fixed erythematous protruding nodule 0.5 cm in diameter (Fig. 1A). The results of punch biopsy for complete removal showed a polypoid tumor constricted at its base and lateral sides by acanthotic epidermis with collarette-like changes (Fig. 1B). Collagenous bundles were filled mostly with myxoid materials and numerous spindle cells arranged in a loose fascicular pattern (Fig. 1C). No nuclear atypia or mitoses were identified. Immunohistochemistry revealed most proliferative spindle cells were positive for CD34 (Fig. 1D) and vimentin (Fig. 1E) but negative for CD99, S-100, and smooth muscle actin. Prominent myxoid stroma was detected by Alcian blue stain (Fig. 1F). On the basis of these findings, the lesion was diagnosed as CDF. After the lesion was completely removed, the patient did not experience any recurrence over 18 months of follow-up. Fig. 1 (A) An erythematous fixed protruding nodule 0.5 cm in diameter on the ventral part of the proximal phalanx of the patient's right index finger. (B~F) Low-magnification view of the specimen indicates a polypoid tumor protruding above the surrounding skin. ... Since McNiff et al.1 first described CDF in 2005, their observations have been regarded as important for the diagnosis of fibrohistiocytic neoplasms, which can be easily misdiagnosed as superficial acral fibromyxoma (SAFM)2. We initially considered a diagnosis of SAFM in our case; however, clinically, SAFMs are slow-growing asymptomatic tumors that commonly present as solitary lesions ranging from 0.5 to 5 cm in diameter3,4. The lesion in the present case was relatively smaller than typical SAFMs. Histopathologically, both SAFM and CDF can be characterized by spindle to stellate cells arranged in a storiform or fascicular pattern with variable degrees of myxoid background stroma5. Accentuated microvasculature and conspicuous mast cells are potentially suggestive of SAFM; meanwhile, keratin horn and epidermal collarette are commonly observed in CDF4,5. In our case, the nodule showed proliferation of spindle cells in a loose fascicular pattern; however, it was constricted at its base and lateral sides by collarette-like acanthotic epidermis. No vascular proliferation, atypical mitoses, or fibroblasts oriented vertically to the axis of the lesion were observed. In addition, the lesion was negative for CD99. Therefore, the tumor was consistent with a diagnosis of CDF. If lesions resemble myxoid fibrohistiocytic tumors (Table 1), immunohistochemistry can be used for an accurate diagnosis of CDF. Table 1 Characteristics of myxoid soft-tissue tumors mimicking cellular digital fibroma McNiff et al.1 report that the natural course of CDF appears to be benign owing it its small size, unremarkable cytology, and absence of recurrence after biopsy. However, elucidating the detailed pathophysiology and clinical characteristics of CDF requires additional case reports. Rare cases of CDF, such as the one presented herein, must be distinguished from other cutaneous fibrohistiocytic tumors including SAFM.

Brainstem auditory evoked potential findings in a French bulldog with bilaterally congenital sensorineural deafness

Abstract : A 3-month-old, intact male French bulldog was suspected of deafness. The dog was irresponsive toenvironmental noises generated out of sight, but normal responses were noted for visual stimuli. No abnormalitieswere observed on the neurological, otoscopic, radiographic, and blood examinations. To diagnose the apparent deafness,brainstem auditory evoked potential (BAEP) was recorded in the presented dog together with a normal dog. Whilethe BAEP from the control dog showed a normal wave consisting of 5 peaks, absence of all peaks was noted inthe suspected deaf dog. Therefore the dog was definitively diagnosed as bilaterally congenital sensorineural deafness.Keywords : brainstem auditory evoked potential, congenital sensorineural deafness, French bulldog In recent decades, the occurrence of congenital deafnesshas been increased in dogs relative to the increased aware-ness among breeders, owners and clinicians [13]. Generally,auditory function is necessary for avoiding traffic accidentand other danger incidence. Because deaf dogs are easily sur-prised and have an increased tendency to bite, they are hardlysuitable for use as working. Therefore the puppy with bilat-eral deafness needs to be trained by a responsible owner, butthis kind of training is difficult and unfamiliar. By these rea-sons, bilaterally deaf puppies are easily euthanized [7].If the proper diagnosis of hearing impairment could bedone in dogs, especially working breeds, it will decrease costand efforts for being needed in training. Bilateral deafnesscould be evaluated by monitoring behavioral responses forsound stimuli presented outside of the visual field or with theanimal blindfolded, taking care to avoid visual or vibratorycues [11]. However, behavioral testing is often unreliable andsubjective [1]. Therefore several objective methods, includ-ing electroaudiomerty-encephalographic, audiometry, respira-tory audiometry, tympanometry, auditory evoked responses,and acoustic reflexes, have been used for diagnosing audio-logical or otological disorders in veterinary medicine [10].Among those methods, the brainstem auditory evoked poten-tial (BAEP) has been proven to be the most objective andnon-invasive assessment of auditory function [14, 15]. There-fore the BAEP is frequently used as a screening test for deaf-ness. Previously congenital deafness had been recognized inFrench bulldog, but the BAEP finding has not been reportedin this breed [11, 13]. Therefore this report firstly describesthe clinical and diagnostic features of bilaterally congenitalsensorineural deafness (CSD) in a French bulldog using theBAEP.A 3-month-old, intact male French bulldog was presentedwith suspected deafness. This dog was the youngest onefrom 4 literamates, and the other 3 littermates had no hear-ing disabilities or other diseases. The owner had not observedany response of the dog for sound stimuli since 1 month agoadoption. There was no history of exposure to any causes ofdeafness; illness, head trauma or ototoxic drugs. Physicalexamination revealed mild erythema on the bilateral earpinna and epidermal collarettes on the abdomen. Its coatcolor was predominantly white and black, especially whiteareas presented on the ventral thorax, abdomen, feet, foreleg,and head. On behavior testing, the dog was irresponsive toenvironmental noises generated out of sight, but normalresponses were noted for visual stimuli. Any startle responseswere not elicited to sudden loud noises. Bilaterally, intacttympanic membranes and the grossly normal external earcanals were observed on the otoscopic examination. Thetympanic bulla was examined by radiography with differentviews of the open mouth dorsolateral, lateral-oblique, androstrocaudal projections. Those radiographic studies revealednormal bone density and no fluid density or diminution offoraminal detail within the tympanic bulla. In addition,

Basal cell carcinoma with an epidermal collarette and ductal differentiation on the dorsal foot

Basal cell carcinoma with an epidermal collarette and ductal differentiation on the dorsal foot

Erythema multiforme minor in a dog following inappropriate intranasal Bordetella bronchiseptica vaccination: a case report

A one-year-old, intact female, Yorkshire terrier dog was presented with a six-month history of multifocal, polycyclic erythematous lesions with epidermal collarette formation at the axillae, the trunk and ventral abdomen. The dog had a history of an inappropriate vaccine administration one day prior to the onset of clinical signs. The histopathology of the lesions revealed apoptosis of keratinocytes in the overlying epidermis, hydropic degeneration and lymphocytic exocytosis. The clinical signs and histopathology of the lesions were compatible with erythema multiforme. The skin lesions resolved after treatment with prednisolone combined with azathioprine for one month. No recurrence of clinical signs occurred during the follow-up period (four months). This is the first case report of erythema multiforme associated with an accidental subcutaneous injection of a Bordetella bronchiseptica vaccine.