Cutaneous Malignant Squamomelanocytic Tumor: A Case Report of a Rare Neoplasm.

ABSTRACT: Cutaneous squamomelanocytic tumor (SMT) is an exceedingly rare cutaneous malignancy characterized by the presence of both squamous cell carcinoma and malignant melanoma within a single tumor. SMT typically presents clinically as keratotic skin papulonodules, most commonly occurring on the face, scalp, or other sun-exposed areas of middle-aged to elderly White male patients. Owing to the rare nature of this tumor, the histogenesis and prognosis remain relatively unclear. Histopathological examination of the tangential biopsy revealed an invasive cutaneous malignancy consisting of 2 distinct yet closely associated atypical cell populations: (1) a population of atypical squamoid epithelial cells arranged in cords and keratin pearls and (2) a population consisting of atypical, spindled cells with fine melanin pigment arranged in confluent sheets. Both populations of atypical cells emanated in an invasive pattern from the underside of the overlying epidermis into the deep dermis. Squamomelanocytic tumors are among the rarer types of collision tumors between 2 malignant lesions as most are basomelanocytic. For most reported SMTs, the melanoma population comprises epithelioid cell morphology, whereas our tumor is composed of spindled cell morphology. In this article, we exemplify a unique case of SMT in an 87-year-old male patient.

Cutaneous nontuberculous mycobacteria infections: A retrospective case series of 78 patients from the Texas Gulf Coast region.

BACKGROUND: The incidence of cutaneous nontuberculous mycobacteria (NTM) infections is increasing. These infections are a diagnostic and therapeutic challenge. OBJECTIVE: We investigated the clinical features, diagnosis, and management of cutaneous NTM infections. METHODS: A retrospective case series studied 78 patients from a Gulf Coast tertiary referral center diagnosed with cutaneous NTM infection by culture or stain of a skin biopsy specimen. RESULTS: A history of trauma, procedure, or environmental exposure was common. The mean time between the initial evaluation and diagnosis was 12 weeks. Only 15% of acid-fast bacillus-positive cultures had a positive acid-fast bacillus smear, and only 43% of those accompanied by skin biopsy specimen had a positive Fite stain. Immunosuppressed patients were more likely to have a positive Fite stain. Treatment included surgery and multiple antibiotics. Immunosuppressed patients and Mycobacterium abscessus group infections were more likely to have persistent disease. LIMITATIONS: M chelonae and M abscessus isolates were indistinguishable and therefore were reported together. Five cases were not confirmed by culture. CONCLUSIONS: Even with clinical suspicion, the diagnosis of NTM infection can be difficult. Results of acid-fast bacillus smears and special stains are frequently negative. Antibiotic resistance is common. Multidrug treatment is often required, and surgical therapy may be needed.

Chronic myelomonocytic leukemia masquerading as cutaneous indeterminate dendritic cell tumor: Expanding the spectrum of skin lesions in chronic myelomonocytic leukemia.

Chronic myelomonocytic leukemia (CMML) is a hematopoietic stem cell neoplasm exhibiting both myelodysplastic and myeloproliferative features. Cutaneous involvement by CMML is critical to recognize as it typically is a harbinger of disease progression and an increased incidence of transformation to acute myeloid leukemia. Cutaneous lesions of CMML exhibit heterogeneous histopathologic features that can be challenging to recognize as CMML. We describe a 67-year-old man with a 3-year history of CMML who had been managed on single-agent azacitidine with stable disease before developing splenomegaly and acute onset skin lesions. Examination of these skin lesions revealed a dense infiltrate of histiocytic cells morphologically resembling Langerhans type cells (lacking frank histopathologic atypia), and with the immunophenotype of an indeterminate cell histiocytosis (S100+ CD1a+ and langerin-). Given the history of CMML, next-generation sequencing studies were performed on the skin biopsy. These revealed a KRAS (p.G12R) mutation identical to that seen in the CMML 3 years prior, establishing a clonal relationship between the 2 processes. This case expands the spectrum for and underscores the protean nature of cutaneous involvement by CMML and underscores the importance of heightened vigilance when evaluating skin lesions of CMML patients.

Porcine xenograft biosynthetic wound dressings for the management of postoperative Mohs wounds.

Cadaveric allografts and a large variety of other biologic dressings have been reported as being useful for the postoperative management of Mohs micrographic surgery (MMS) wounds. Although the use of porcine xenografts for the immediate postoperative management of these wounds is known, their use has not been detailed in the dermatology literature. A case series of 15 consecutive Mohs micrographic surgery patients (mean age = 74.9 years, range = 49 to 89 years) with wounds initially managed with porcine xenografts is described. Porcine xenografts were useful in a variety of clinical settings following MMS. These included: (1) wound management when tumor margins were indeterminate pending additional dermatopathology studies and (2) wound management when there are issues such as through and through nasal defects involving the mucosa, large wound depth, exposed cartilage and or bone, or patient medical comorbidities that delay or prevent plans for immediate wound reconstruction. Future controlled studies of biologic dressings are needed to determine which options are best for micrographic surgery wounds. Comparisons should also include the traditional option of second intention healing without biologic dressings.

Contact Dermatitis and Medical Adhesives: A Review.

In more recent years, the use of medical adhesives in lieu of sutures or staples has become increasingly common for the closure of post-surgical and traumatic incisions in areas of the skin where tension is low. While medical adhesives possess many advantages and little risk of adverse side effects, there are increasing numbers of accounts in the medical literature of allergic contact dermatitis (ACD) caused by specific components contained within the medical adhesives. The goal of this paper is to provide physicians with a differential diagnosis when faced with complications after the use of medical adhesives for wound closure. Additionally, this paper aims to delineate the differences among the most commonly used adhesives, provide a rationale for assessing an individual's personal risk of developing ACD, and to highlight the unique advantages and disadvantages of each adhesive.  Dermabond® appears to be the most versatile adhesive with the lowest risk of ACD. However, because of its high cost, it may not be appropriate for all patients. While Mastisol® can only be utilized in combination with a dressing, such as Steri-Strips®, it is much more affordable than Dermabond and is still capable of providing an effective wound closure. Due to these factors, it is our recommendation that Dermabond is considered the first-line medical adhesive due to its versatility and strength, while Mastisol can be readily employed in situations with financial consideration. As the number of patients treated with medical adhesives continues to grow, physicians should anticipate an increase in the number of cases of ACD secondary to adhesive sensitization. It is imperative for physicians to be able to differentiate between a case of ACD and another potentially more serious complication, such as cellulitis. We hope that this paper will assist providers in distinguishing adhesive-induced ACD and other complications, identifying patients at risk of ACD from adhesive use, and provide a basis for which adhesives are most appropriate for any given patient.