Persistent Thrombotic Hemangioma With Organizing/Anastomosing Features: A Case Report of a Guanine Nucleotide-Binding Protein Alpha Subunit (GNA)-Mutated Cutaneous Vascular Lesion.

Thrombotic hemangioma with organizing/anastomosing features (THOA) is a newly identified variant within the spectrum of hemangiomas that harbor mutations in the guanine nucleotide-binding protein alpha subunit (GNA) genes (like GNAQ or GNA11). While THOA shares similarities with anastomosing hemangioma, it possesses distinct clinical and morphological characteristics that make it a separate entity. All reported cases of THOA have demonstrated benign behavior. However, histologic features such as anastomosing vascular growth, mitotic figures, and endothelial hobnailing may raise concerns for a low-grade malignant vascular neoplasm. We report the case of a 74-year-old female with an unremarkable medical history who presented with a vascular lesion on her upper torso. The lesion persisted after the initial biopsy and was re-excised, displaying similar histologic characteristics. Next-generation sequencing (NGS) revealed a GNAQ mutation (p.Q209H) in both samples. Notably, a TP53 mutation (p.R273H) was detected in the first specimen but was absent in the subsequent excision. The lesion was diagnosed as persistent THOA. This case report discusses the salient features, genetic profile, and prognosis of this uncommon lesion.

A Unique Case of Cutaneous Schwannoma With Coexistent Masson's Hemangioma.

Schwannomas (SCHs) are benign neural tumors originating from Schwann cells of the peripheral nerve sheaths. These neoplasms typically exhibit hyalinized vessels with impaired vascular permeability; however, angioma-like features are rare. We report an intriguing case of a cutaneous SCH with unusual vascular changes in a 60-year-old female who presented with a tender nodular lesion on her lower back. Histopathological examination of the excised lesion revealed a schwannoma with a central area of thrombosis and a vascular proliferative lesion consistent with Masson's hemangioma (MH). MH, also known as intravascular papillary endothelial hyperplasia (IPEH), is a rare benign vascular lesion characterized by papillary endothelial hyperplasia and obliterative changes within vascular lumens. Immunohistochemical staining confirmed S100 positivity in the SCH component and highlighted the papillary endothelial lining by ERG (erythroblast transformation-specific regulated gene 1). To our knowledge, this is the first report of a schwannoma harboring MH. This unique case underscores the potential for rare vascular proliferation to arise within otherwise typical SCHs.

Melan-A-Positive Granular Cell Tumor With Extensive Intraneural and Perineural Spread: A Rare Case Report.

Cutaneous granular cell tumors (GCTs) are rare tumors that typically exhibit benign clinical behavior and are likely of Schwann cell origin. Some histologic and immunohistochemical variants of GCTs may present challenges due to infiltrative growth patterns, perineural invasion, and expression of Melan-A. In this case report, we present a 27-year-old male who had previously been diagnosed with a typical GCT on the back a few years ago. The current biopsy from the proximal palm demonstrated a cytologically similar tumor with extensive perineural spread and notable positivity for Melan-A. Although uncommon, these features are consistent with the histological appearances of GCTs. The current views on the histogenesis of GCTs, clinical associations, differential diagnosis with melanoma, and histological criteria for malignant GCTs are discussed. A panel of immunohistochemical stains, including Inhibin-α and preferentially expressed antigen in melanoma (PRAME), is proposed for use in rare instances of Melan-A-positive GCTs.

Focusing of high-intensity ultrasound through the rib cage using a therapeutic random phased array.

A method for focusing high-intensity ultrasound (HIFU) through a rib cage that aims to minimize heating of the ribs while maintaining high intensities at the focus (or foci) was proposed and tested theoretically and experimentally. Two approaches, one based on geometric acoustics and the other accounting for diffraction effects associated with propagation through the rib cage, were investigated theoretically for idealized source conditions. It is shown that for an idealized radiator, the diffraction approach provides a 23% gain in peak intensity and results in significantly less power losses on the ribs (1% vs. 7.5% of the irradiated power) compared with the geometric one. A 2-D 1-MHz phased array with 254 randomly distributed elements, tissue-mimicking phantoms and samples of porcine rib cages are used in experiments; the geometric approach is used to configure how the array is driven. Intensity distributions are measured in the plane of the ribs and in the focal plane using an infrared camera. Theoretical and experimental results show that it is possible to provide adequate focusing through the ribs without overheating them for a single focus and several foci, including steering at +/- 10-15 mm off and +/- 20 mm along the array axis. Focus splitting caused by the periodic spatial structure of ribs is demonstrated both in simulations and experiments; the parameters of splitting are quantified. The ability to produce thermal lesions with a split focal pattern in ex vivo porcine tissue placed beyond the rib phantom is also demonstrated. The results suggest that the method is potentially useful for clinical applications of HIFU, for which the rib cage lies between the transducer(s) and the targeted tissue.