Melanocytic hyperplasia associated with surgical scars in basal cell carcinoma re-excision specimens: A single-center retrospective study.

BACKGROUND: Melanocytic hyperplasia (MH) overlying surgical scars has been reported but MH adjacent to the scar has not been previously addressed. METHODS: We evaluated scar-associated MH in 489 re-excision specimens of basal cell carcinoma. Melanocytic density, confluence, atypia, suprabasal scatter, follicular extension, distance from the scar, correlation with clinicopathologic parameters, and PRAME expression were recorded. RESULTS: One hundred seventy-seven of 489 (36%) cases exhibited MH beyond the scar extending to 6.65 mm median distance, with a median density of 13 melanocytes/0.5 mm (6-24 mm), confluence in 74 (42%) cases, atypia in 14 (8%), suprabasal melanocytes in 25 (14%), and follicular extension in 21 (12%). Mean age of MH group was significantly lower than non-MH group (P < 0.0001). MH overlying the scar was significantly higher in specimens with elastosis than those without elastosis (P < 0.0001). PRAME expression was absent in 14 of 20 cases and present in rare melanocytes in 6 cases. CONCLUSIONS: Increased melanocytic density with confluence, mild atypia, suprabasal scatter, and superficial follicular extension may be observed in re-excision specimens adjacent to surgical scars in the absence of a melanocytic neoplasm. These observations are helpful for appropriate interpretation of melanoma re-excision specimens, to avoid potential pitfalls in diagnosis and unnecessary therapeutic measures.

Without Missing a Beat: Absence of Cilia Informs the Diagnosis of Histopathologically Challenging Spitzoid Melanocytic Neoplasms.

The diagnosis of Spitzoid melanocytic lesions remains a formidable challenge in dermatopathology. Numerous ancillary tests have evolved to improve accurate classification of histopathologically ambiguous lesions. A study by Lang et al. (2020b) demonstrates loss of primary cilia in Spitzoid melanoma compared with Spitz nevi and positions ciliation index as an informative ancillary test for Spitzoid lesions.

T-Cell Repertoire in Combination with T-Cell Density Predicts Clinical Outcomes in Patients with Merkel Cell Carcinoma.

The integrity of the immune system represents a pivotal risk factor and prognostic biomarker for Merkel cell carcinoma. A higher density of tumor-associated T cells correlates with improved Merkel cell carcinoma-specific survival, but the prognostic importance of the T-cell infiltrate reactivity is unknown. We evaluated the T-cell receptor repertoire associated with 72 primary Merkel cell carcinomas and correlated metrics of the T-cell receptor repertoire with clinicopathologic characteristics and patient outcomes. We showed that a high Simpson's Dominance index (SDom) was significantly associated with fewer metastases (P = 0.01), lower stage at presentation (P = 0.02), lower final stage at last follow-up (P = 0.05), and longer time to first lymph node metastasis (P = 0.04). These correlations were mostly preserved in the Merkel cell polyomavirus-negative subgroup. Combining SDom with CD3+ or CD8+ T-cell density revealed three distinct prognostic groups with respect to disease-specific survival. Patients with both high SDom and high CD3+ or CD8+ T-cell density had markedly improved disease-specific survival compared with patients with low SDom and low CD3+ or CD8+ T-cell density (P = 0.002 and P = 0.03, respectively). Patients with either high SDom or high CD3+ or CD8+ had intermediate disease-specific survival. Our findings demonstrate that the quality of the tumor-associated T-cell infiltrate informs patient prognosis in primary Merkel cell carcinoma beyond the T-cell density.

Lichen planus related to transforming growth factor beta inhibitor in a patient with metastatic chondrosarcoma: a case report.

Transforming growth factor-beta1 (TGF-ß1) is expressed in normal epidermis. TGF-ß1 potently inhibits keratinocyte proliferation and immunomodulatory properties, mainly by suppressing immune responses to self-antigens. Lichen planus (LP) is a form of dermatitis caused by cell-mediated immune dysfunction, but the exact pathogenic pathways are unknown, which poses therapeutic challenges. We report on a 68-year-old man who developed multiple pruritic, discrete, and well-demarcated, flat-topped red-purple papules and macules on the back and upper arms following 4 cycles of treatment with TGF-ß receptor I (TGFBR-I) inhibitor, ly3200882, for metastatic chondrosarcoma. The biopsy showed hyperkeratosis, wedge-shaped hypergranulosis, elongation of the rete ridges, and a dense band-like lymphohistiocytic infiltrate admixed with colloid bodies and pigment incontinence, consistent with LP. Temporal correlation suggested that the TGFBR-I inhibitor might be a trigger. Treatment with topical clobetasol and oral metronidazole led to partial resolution of the lesions with postinflammatory hyperpigmentation. We believe this is the first reported case of LP related to TGFBR-I inhibitor therapy. This report expands the list of cutaneous adverse events associated with this novel class of targeted therapy. More importantly, this report supports emerging evidence that failure of TGF-ß1 activation/signal transduction is an important mechanism in the pathogenesis of LP and suggests the TGF-ß1 pathway as a potential therapeutic target in this disease.

Cutaneous spindle cell adenolipoma with eccrine and apocrine differentiation.

Cutaneous spindle cell adenolipoma (SCAL) is a recently described rare variant of lipoma with 11 cases reported to date. Here we report a consultation case of a 77-year-old male who presented with a nodule on the right nasolabial fold, diagnosed as apocrine fibroadenoma or sebaceous hyperplasia by an outside pathologist. The specimen revealed an ill-defined dermal tumor composed of mature adipocytes, bland spindle cells, ropey collagen, and dilated eccrine and apocrine glands and ducts in a fibromyxoid stroma. The spindle cells were positive for CD34 and negative for S100 protein and SOX10. These findings are consistent with those of cutaneous SCAL. The pathogenesis of this entity is controversial and includes a hamartomatous process, derivation from adipose tissue surrounding eccrine glands, or preexisting glands entrapment within a growing lipoma. In the present case, the glandular component is extensive and includes both eccrine and apocrine differentiation, which has not been previously described and further supports the hamartomatous nature. Awareness of this rare entity is helpful to prevent confusion with other look-alike primary and metastatic cutaneous lesions.

Metastatic melanoma with balloon/histiocytoid cytomorphology after treatment with immunotherapy: A histologic mimic and diagnostic pitfall.

Epithelioid cells with foamy cytoplasm (histiocytoid features) are typical histopathologic findings among benign and malignant histiocytic neoplasms such as xanthoma and atypical fibroxanthoma. However, these changes are unusual in melanoma, which is typically composed of nested and variably pigmented atypical epithelioid cells. Here, we report a patient with metastatic melanoma in lymph nodes presenting with prominent balloon cell/histiocytoid features expressing melanocytic markers, after treatment with nivolumab. This report suggests that the spectrum of neoplasms with histiocytoid features should be expanded to include melanoma, a pattern that, to the best of our knowledge, is uncommon, especially in the setting of post-neoadjuvant therapy.

Epidemiology and susceptibility profiles of diabetic foot infections in five hospitals in Lebanon.

INTRODUCTION: Approximately 80% of diabetes-related lower extremity amputations are preceded by a foot ulcer. Global studies on the epidemiology of diabetic foot ulcer (DFU) infections and guidelines detailing the most common pathogens and their respective antimicrobial susceptibilities are available. While Gram-positive cocci, mainly Staphylococcus species (spp.), were the most common organisms cultured from DFU in the United States, the Gram-negative Pseudomonas spp. were found to be the most common in some Middle Eastern countries. In Lebanon, however, such studies remain scarce. This study, conducted in Lebanon, investigated the most common organisms in DFU infections and their antimicrobial profiles. METHODOLOGY: We collected data from all documented diabetic foot infections between January 2015 and March 2016, 128 participants total, from 5 different hospitals in various regions of Lebanon. RESULTS: Among all isolates, Enterobacteriaceae (42%), Pseudomonas spp. (18.6%) and methicillin-sensitive Staphylococcus aureus (MSSA) (15.3%) were the most frequent bacteria. In addition, 72% of Pseudomonas spp. were susceptible to ciprofloxacin and 63.6% of Enterobacteriaceae were susceptible to either amoxicillin/clavulanate or ciprofloxacin, 91% were susceptible to piperacillin/tazobactam. Methicillin-resistant Staphylococcus aureus (MRSA) was only found in hospitalized patients or those who received prior antibiotics. Polymicrobial infections were documented in only 38% of patients. CONCLUSION: In Lebanon, the most appropriate empirical oral outpatient treatment would be a combination of amoxicillin/clavulanate and ciprofloxacin. As for admitted patients who have failed the oral regimen, piperacillin/tazobactam would then be the treatment of choice.

Surveillance of antimicrobial resistance in Lebanese hospitals: retrospective nationwide compiled data.

Antimicrobial resistance is closely linked to antimicrobial use and is a growing concern worldwide. Antimicrobial resistance increases healthcare costs substantially in many countries, including Lebanon. National data from Lebanon have, in the most part, been limited to a few academic hospitals. The Lebanese Society of Infectious Diseases conducted a retrospective study to better describe the antimicrobial susceptibility patterns of bacterial isolates in Lebanon. Data were based on records retrieved from the bacteriology laboratories of 16 different Lebanese hospitals between January 2011 and December 2013. The susceptibility results of a total 20684 Gram-positive and 55594 Gram-negative bacteria were analyzed. The prevalence rate of methicillin-resistant Staphylococcus aureus was 27.6% and of vancomycin-resistant Enterococcus spp was 1%. Streptococcus pneumoniae had susceptibilities of 46% to oxacillin, 63% to erythromycin, and 98% to levofloxacin. Streptococcus pyogenes had susceptibilities of 94% to erythromycin and 95% to clindamycin. The mean ampicillin susceptibility of Haemophilus influenzae, Salmonella spp, and Shigella spp isolates was 79%, 81.3%, and 62.2%, respectively. The extended-spectrum beta-lactamase production rate for Escherichia coli was 32.3% and for Klebsiella spp was 29.2%. Acinetobacter spp showed high resistance to most antimicrobials, with low resistance to colistin (17.1%). Pseudomonas spp susceptibilities to piperacillin-tazobactam and imipenem were lower than 80% (79.7% and 72.8%, respectively). This study provides population-specific data that are valuable in guiding antimicrobial use in Lebanon and neighbouring countries and will help in the establishment of a surveillance system for antimicrobial resistance following the implementation of a nationwide standardization of laboratory methods and data entry.

16S-23S rRNA Gene Intergenic Spacer Region Variability Helps Resolve Closely Related Sphingomonads.

Sphingomonads comprise a physiologically versatile group many of which appear to be adapted to oligotrophic environments, but several also had features in their genomes indicative of host associations. In this study, the extent variability of the 16S-23S rDNA intergenic spacer (ITS) sequences of 14 ATCC reference sphingomonad strains and 23 isolates recovered from drinking water was investigated through PCR amplification and sequencing. Sequencing analysis of the 16S-23S rRNA gene ITS region revealed that the ITS sizes for all studied isolates varied between 415 and 849 bp, while their G+C content was 42.2-57.9 mol%. Five distinct ITS types were identified: ITS(none) (without tRNA genes), ITS(Ala(TGC)), ITS(Ala(TGC)+Ile(GAT)), ITS(Ile(GAT)+Ala(TGC)), and ITS (Ile(GAT)+Pseudo). All of the identified tRNA(Ala(TGC)) molecules consisted of 73 bases, and all of the tRNA(Ile(GAT)) molecules consisted of 74 bases. We also detected striking variability in the size of the ITS region among the various examined isolates. Highest variability was detected within the ITS-2. The importance of this study is that this is the first comparison of the 16S-23S rDNA ITS sequence similarities and tRNA genes from sphingomonads. Collectively the data obtained in this study revealed the heterogeneity and extent of variability within the ITS region compared to the 16S rRNA gene within closely related isolates. Sequence and length polymorphisms within the ITS region along with the ITS types (tRNA-containing or lacking and the type of tRNA) and ITS-2 size and sequence similarities allowed us to overcome the limitation we previously encountered in resolving closely related isolates based on the 16S rRNA gene sequence.