Cat Scratch Disease of the Breast/Axilla: Recognition of a Rare Disease and Approaches for Differential Diagnosis.

Cat scratch disease rarely presents as a breast or axillary mass mimicking carcinoma both clinically and radiologically. Diagnosing breast/axillary cat scratch disease is challenging due to its rarity and nonspecific findings. Here, we reported 2 patients with breast cat scratch disease and reviewed 14 patients with cat scratch disease involving breast/axilla from the past 30 years. It mainly affects women (median age: 48), consistently presenting as axillary lymphadenopathy, and demonstrates ipsilateral breast mass in half of patients (50%, 8/16). The breast mass was most commonly located in the upper outer quadrant (88%, 7/8), indicating the possibility of disease extension from axillary adenopathy. Around half of patients (56%, 9/16) reported cat exposure. Histologically, most patients (93%, 14/15) presented as necrotizing granulomas, with characteristic stellate-shaped necrosis in 5 patients. Although pathologic differential diagnoses between cat scratch disease and cancer are straightforward, distinguishing cat scratch disease from other granulomatous mastitis poses diagnostic challenges. Silver stains should be included in the diagnostic workup panel when highly suspecting cat scratch disease clinically. However, they were only able to highlight the causative microorganism in 54% (7/18) patients, and the gram stain was negative in all 12 tested patients. In contrast, polymerase chain reaction (PCR) for the causative microorganism was consistently positive in all 3 tested patients, while serologic test confirmed diagnosis in 85% (11/13) patients; 1 patient with negative serology showed a positive PCR result. Therefore, upfront PCR tests with or without serologic study should be considered to confirm the diagnosis of cat scratch disease in a timely manner.

ALK-positive Large B-Cell Lymphoma Presenting as a Circumscribed Breast Mass with Germinal Center Immunophenotype.

We report a rare case of ALK-positive large B cell lymphoma which initially presented as a circumscribed breast mass in a young woman mimicking fibroadenoma. The lymphoma demonstrated typical immunoblastic morphology with monomorphic round nuclei and prominent central nucleoli. Immunophenotypically, the lymphoma was positive for MUM1,CD138, BOB1, OCT2, PAX5 (focal), CD4, and was negative for CD20, CD79a and all other T cell antigens. Immunostaining for the ALK protein revealed the characteristic granular cytoplasmic staining typical for ALK-positive large B cell lymphoma with an ALK::CTCL fusion confirmed on genomic profiling study. Notably the cells also expressed CD10 and BCL6. Staging revealed disseminated disease with blood, bone marrow and liver involvement. To our knowledge, this is the first report of ALK-positive large B cell lymphoma initially presenting as a breast lesion. Additionally, expression of CD10 and BCL6 suggested a germinal center origin for the lesion.

Cutaneous leishmaniasis mimicking inflammatory and neoplastic processes: a clinical, histopathological and molecular study of 57 cases.

BACKGROUND: Cutaneous leishmaniasis displays considerable variation in its histopathological and clinical presentation. Clinically, it progresses from a papule into a painless ulcerated and crusted nodule/papule. Microscopically, it progresses from sheets of amastigote-filled histiocytes to granulomatous inflammation. METHODS: The study was conducted on 145 skin biopsies from untreated patients with histopathological and/or clinical suspicion of cutaneous leishmaniasis in Lebanon, Syria and Saudi Arabia (1992-2010). The pre-biopsy clinical diagnosis and demographic data were collected. Biopsies were evaluated for the major microscopic pattern, and the parasitic index (PI) was also determined. Diagnosis was confirmed by polymerase chain reaction (PCR) followed by molecular sub-speciation. RESULTS: Of the 145 patients, 125 were confirmed as cutaneous leishmaniasis by PCR. Eighteen cases presented with a pre-biopsy clinical diagnosis other than cutaneous leishmaniasis that ranged from dermatitis to neoplasm. Of the 125 cases, 57 showed a major histopathological pattern other than cutaneous leishmaniasis. Identification of amastigotes was equivocal (PI ≤1) in 38 of the 57 cases. Of interest, all the 18 cases with a pre-biopsy clinical diagnosis other than cutaneous leishmaniasis also showed atypical histopathology for cutaneous leishmaniasis. CONCLUSIONS: The manifestations of cutaneous leishmaniasis are broad and may mimic other inflammatory and neoplastic diseases. Pathologists and dermatologists should be aware of such pitfalls and can utilize PCR to confirm the diagnosis of leishmaniasis.

Signet-ring cells in pleural and peritoneal effusions identified on Wright stains - A diagnostic pitfall.

Objectives: Signet-ring cells (SRCs) in effusion specimens represent a diagnostic challenge. In this study, a consecutive series of pleural and peritoneal effusions with benign SRCs are examined and compared with malignant SRCs. Material and Methods: We reviewed consecutive Wright-stained serous effusion slides and searched for cases with SRCs. Corresponding ThinPrep slides and clinical histories were reviewed. Cytology cases with known signet-ring adenocarcinoma were retrieved and reviewed. Results: Four hundred Wright-stained serous effusions were reviewed. Eighteen cases were identified with SRC-like cells. Thirteen patients had liver cirrhosis, three patients had end-stage renal disease, one patient had a history of pancreatic adenocarcinoma, and one patient had endometrioid carcinoma. For the latter two patients, the primary tumor showed no histologic findings of signet-ring features. In all cases, no SRCs were found on the corresponding ThinPrep slides. Five cytology cases with malignant SRCs were reviewed. Benign SRCs have a uniformly pale and markedly distended cytoplasm, and the nuclei are thin and curved. The malignant SRCs showed larger non-curved nuclei and bubbly mucin-containing cytoplasm. Conclusion: Mesothelial cells and histiocytes can mimic signet-ring adenocarcinoma cells on Wright-stained slides. Correlation with ThinPrep specimens is necessary before reporting, as the SRCs typically are not present in ThinPrep preparations.

Verruciform xanthoma: a special epidermal nevus.

Congenital hemidysplasia with ichthyosiform nevus and limb defects (CHILD) syndrome is a rare X-linked hereditary disorder. Presentation varies from ichthyosiform nevus to complete limb amelia. We present a 17-year-old adolescent girl who presented with a 16-cm exophytic mass of the right foot that had been growing for 7 years as well as knee contracture. Deformed nails with onychorrhexis were noted bilaterally. History of multiple nonlinear erythematous skin lesions covered by dry waxy scales involving multiple body folds with sharp midline demarcation was obtained. The patient's family history was negative for consanguinity and similar conditions. Radiography showed right leg hypoplasia and osteopenia. These findings fulfill the diagnosis of CHILD syndrome. Microscopically, psoriasiform epidermal hyperplasia with marked orthohyper-keratosis and neutrophilic exocytosis were noted. The papillary dermis was packed with foamy macrophages consistent with xanthomatous changes, namely verruciform xanthoma. Verruciform xanthoma, although rarely found in other conditions, is a characteristic finding.

Mammary mesenchymal and fibroepithelial lesions: An illustrated cytomorphologic update with differential diagnoses.

The Uniform Approach to Breast Fine Needle Aspiration Biopsy was put forward by a learned group of breast physicians in 1997. This landmark manuscript focused predominantly on diagnosis and reporting of mammary epithelial lesions. Today, most American practitioners turn initially to core biopsy rather than aspiration biopsy for the first line diagnosis of solid breast lesions; however, recent efforts from the International Academy of Cytology have produced a system called the Standardized Reporting of Breast Fine Needle Aspiration Biopsy Cytology (colloquially labeled in 2017 as the "Yokohama System"), suggesting a new interest in breast fine needle aspiration (FNA), especially in resource limited settings or clinical practice settings with experienced breast cytopathologists. Fibroepithelial lesions of the breast comprise a heterogeneous group of biphasic tumors with epithelial and stromal elements. Mesenchymal lesions of the breast include a variety of neoplasms of fibroblastic, myofibroblastic, endothelial, neural, adipocytic, muscular, and osteo-cartilaginous derivations. The cytology of mesenchymal breast lesions is infrequently described in the literature and is mainly limited to case reports and small series. This illustrated review highlights the cytologic features of fibroepithelial and mesenchymal mammary proliferations and discusses differential diagnoses and histomorphologic correlates.

Unsatisfactory exfoliative anal cytology samples, 15-year experience with histologic, cytologic, and molecular follow-up.

BACKGROUND: The incidence of anal carcinoma has risen in recent decades. Exfoliative cytology screening of selected high risk patients is performed in many centers. Unsatisfactory cytology results are frustrating to patients, clinicians, and laboratorians. The aim of this study is to ascertain outcomes of patients with non-diagnostic anal cytology. METHODS: A retrospective review of anal cytology testing performed at the Cleveland Clinic between 01/01/2001 and 12/31/2015 was performed. All cases were received as liquid-based samples and processed as ThinPreps (Hologic, Marlborough, MA). Co-testing for HR-HPV DNA was performed using Hybrid Capture 2® (Qiagen, Germantown, MD) in the majority of patients. RESULTS: Of 1,276 ThinPrep anal cytology samples, 130 (10%) were deemed unsatisfactory. 77% of patients were HIV positive. 85% were males. Of the unsatisfactory cases, 116 (89%) were co-tested for HR-HPV DNA. Of those, 40 patients (34%) had a simultaneous positive HR-HPV DNA. Adequate follow up cytology within a one year and a two year period revealed that 18/130 (14%) and 26/130 (20%) of patients had ASC or SIL respectively. Histologic follow-up within one and two years showed 3 patients (2%) and 8 patients (6%) with HSIL or worse. CONCLUSIONS: High risk patients with unsatisfactory anal cytology are not "negative". At least one-third proved to be concomitantly HR-HPV DNA positive with one-fifth showing subsequent cytologic squamous abnormalities and with more than 5% being diagnosed with a high grade intraepithelial lesion within two years. Prompt repeat cytology and/or HR-HPV DNA is recommended for high risk patients with non-diagnostic cytology.