A 10-year-old, spayed female, Domestic Shorthaired cat was referred for surgical removal of a mass on the left vulval fold. An impression smear revealed mixed cell inflammation, with eosinophils predominating focally, and a concurrent bacterial infection, suggesting a primarily inflammatory lesion. However, cytology of a fine-needle aspirate of the mass revealed a neoplastic epithelial cell population, confirmed on histopathology as an apocrine vulval adenocarcinoma with lymphatic invasion and marked tumour-associated tissue eosinophilia. One month after surgical excision of the mass, the cat developed inguinal metastatic lymphadenopathy and chemotherapy was initiated. The patient ultimately developed marked peripheral lymphadenomegaly and was euthanized due to concerns for overall quality of life and comfort. This case highlights that neoplasia should be a consistent differential diagnosis for eosinophilic infiltrates/inflammation. The distinct appearance of the two cytological samples in this case stresses the need for sampling of different sites of a lesion and the importance of not relying on superficial impression smears for clinical management and prognosis.

IgG4-related disease (IgG4-RD) is an inflammatory and fibrosing disease which causes tumor-like swelling of organs and commonly mimics symptoms of malignancy. It has been increasing in prevalence in the last decade, but esophageal involvement remains rare. IgG4-RD was first known to involve certain organs, such as the pancreas. It has, since, been described as a systemic disease process. IgG4-RD should be considered in patients presenting with dysphagia. Initiation of appropriate treatment with corticosteroids can avoid unnecessary procedures and improve outcomes. The aim of this review is to discuss 17 cases of IgG4-RD of the esophagus. Literature review was conducted using NCBI database (PMC and PubMed filters) using the keywords \"IgG4 disease,\" \"sclerosing,\" \"esophagus\" and \"gastrointestinal.\" The search was narrowed to include cases describing IgG4 disease of the esophagus using the same filters. Literature review identified 16 documented cases of IgG4-RD involving the esophagus. Upon literature review, it remains clear that it is extremely rare for IgG4-RD to affect the esophagus. Sixteen cases have been reported. We present a 17th case and discuss the implications of IgG4-RD. It is important to keep a broad differential diagnosis that includes IgG4-RD for patients presenting with dysphagia, especially when symptoms are refractory.

The progression of normal cells to invasive tumor cells has been attributed to the acquisition of numerous mutations in the genome; genomic instability (GI) facilitates the accumulation of these mutations. To study the GI in head and neck squamous cell carcinoma (HNSCC), the genomic instability index (GII) was examined; chromosomal gains and losses were evaluated by array comparative genomic hybridization (aCGH), which were confirmed by fluorescence in situ hybridization (FISH). Histopathological eosinophilic infiltrate (Eos Infil), as an adjunct measure of tumor invasiveness, was also considered and compared to GI.
METHODS: Inter-simple sequence repeat PCR (ISSR-PCR) was utilized to determine the GII (a quantitative estimate of the relative overall genomic damage). GII was measured in 26 pairs of tumor and normal HNSCC samples. Array CGH was conducted using bacterial artificial chromosome (BAC) clones to evaluate amplifications and deletions (n=20 tumor), and confirmation of the specific changes was made by FISH analysis. Histopathological evaluation of Eos Infil for all samples was performed to calculate the eosinophilic index (EI). This was accomplished by observing Eos Infil in neoplastic tissue and at the tumor/normal tissue interface.
RESULTS: GI was evident in 25 of the 26 tumors. The GIIs ranged from 0 to 5.3% with a mean of 2.8% (similar to the results reported for colorectal and thyroid carcinomas). GIIs were higher in tumors of the oral cavity (OC) than in tumors from other subsites of HNSCC (p=0.05). Chromosomal alterations were identified by array CGH on chromosomes 8, 11 and 17, but consistent amplifications were observed on (8q21.3-23.5) in 80% of the tumors. These changes were confirmed using FISH analysis. There was an association between increased GI and rising EI, but this did not achieve statistical significance (p>0.05).
CONCLUSIONS: HNSCC exhibits a similar degree of GI to that previously reported in colorectal and thyroid malignancies. The higher GI identified in OC tumors could be explained by a greater degree of the damage from environmental carcinogens (smoke, diet and alcohol) to the first station of the areodigestive tract. Consistent amplification at the specific loci of 8q might be attributed to mutations in various genes, such as SHAX3 (Snf7 homolog, associated with Alix 3, involved in apoptosis and endocytosis) and E2F5 (transcription factor 5 that interacts with tumor suppressor proteins). EI was not associated with age, sex, site or stage of tumor in established cases. Further work up will be necessary to explain these results.

Methotrexate toxicity in mucocutaneous areas is usually not associated with tissue eosinophilia. We describe a case of acute methotrexate-induced mucocutaneous erosions with interface dermatitis and eosinophils. A 76-year-old African-American woman with a history of bullous pemphigoid on methotrexate therapy presented with lower extremity cellulitis, developing oral and cutaneous erosions during hospitalization after daily dosage of methotrexate. Shallow circular cutaneous erosions were found on chest, abdomen and limbs. Laboratory results showed pancytopaenia and elevated liver function tests. Skin biopsy revealed irregular acanthotic epidermis with interface dermatitis, individual dyskeratotic cells and superficial perivascular lymphocytic infiltrate with numerous eosinophils. Methotrexate was stopped and leucovorin was administered, leading to improvement. The histopathological changes in acute mucocutaneous toxicity range from pauci-inflammatory erosions with dyskeratotic keratinocytes to interface dermatitis and infrequently seen eosinophils. This case exemplifies that interface dermatitis with a marked eosinophilic infiltrate can be found in the setting of acute mucocutaneous methotrexate toxicity.

BACKGROUND: Well\'s syndrome, or eosinophilic cellulitis, is rare in childhood, with fewer than 40 pediatric cases being reported since 1979. The physiopathology is unknown.
METHODS: In February 2012, members of the research group of the Department of Pediatric Dermatology Society submitted their case of Wells\' syndrome in children aged 0-15 years. Details of clinical, biological and histological features and of therapeutic strategies were collected by physicians using a standardized questionnaire. Pictures were reviewed by the authors.
RESULTS: Eleven patients were included (average age: 6 years), with a strong prevalence of atopy (63%). Two types of clinical manifestation were noted: single or multiple cellulitis associated or not with vesiculobullous lesions and fixed urticaria. Eighty-two percent of patients had pruritus and 73% had eosinophilia. For all patients, histological examination of skin biopsies showed an eosinophilic infiltrate extending in the dermis with associated Sweet-like neutrophilic infiltrate being seen in 2 patients. The course of the disease was protracted (mean duration: 8 months) with flare-ups. Treatment varied depending on the doctors (topical or systemic steroids, tacrolimus and dapsone).
CONCLUSIONS: Our study confirms some of the data in the literature concerning the clinical, histological features and course of Well\'s syndrome in children. The key information is the high prevalence of atopic children hitherto unreported. In a setting of insect bites, vaccination, infection or traumatism, this unusual background could explain the onset of inflammatory reaction with eosinophils. Oral or topical steroids appear to be the first-line treatment in children when necessary.
CONCLUSIONS: Well\'s syndrome in children is rare and characterized by its polymorphism. We report for the first time in a series of patients a high prevalence of atopy, which raises new perspectives in understanding these rare diseases. We propose topical steroids as first-line therapy in children with superficial lesions, with oral steroids being given for cellulitic lesions or where topical therapy fails.