Autoimmune and autoinflammatory conditions after COVID-19 vaccination. New case reports and updated literature review.

Autoimmunity linked to COVID-19 immunization has been recorded throughout the pandemic. Herein we present six new patients who experienced relapses of previous autoimmune disease (AD) or developed a new autoimmune or autoinflammatory condition following vaccination. In addition, we documented additional cases through a systematic review of the literature up to August 1st, 2022, in which 464 studies (928 cases) were included.

Metastatic Malignant Pilomatrixoma in an 8-Year-Old Girl Misdiagnosed as a Recurrent Pilomatrixoma.

Malignant pilomatrixoma or pilomatrix carcinoma is a rare, locally aggressive malignant neoplasm, derived from the hair follicle with a high propensity for local recurrence. Only a few cases of metastatic pilomatrixoma have been described in the literature. Till date, only 17 cases have been reported in the English-language medical literature, most commonly occurring associated with local recurrence in adults.

Diagnostic utility of epithelial and melanocitic markers with double sequential immunohistochemical staining in differentiating melanoma in situ from invasive melanoma.

Identification of melanoma in situ and its distinction from invasive melanoma is important because of its significant impact on morbidity and mortality. However, this interpretation can cause pitfalls in the diagnosis even with the use of immunohistochemistry. The aim of this study is to evaluate the diagnostic utility of epithelial makers (AE1/AE3, CK5/6, and p63) combined with melanocytic markers (HMB-45, S-100, or Melan-A) using dual-color immunohistochemical staining, performed on a single slide by sequentially applying the antibodies.

Cutaneous Collision Tumor Associated With Porocarcinomatous and Angiosarcomatous Components: A Potential Diagnostic Pitfall.

Sarcomatoid eccrine porocarcinoma (SEP) is a very rare malignancy including epithelial and mesenchymal components exhibiting pleomorphic cells, nuclear hyperchromasia, and high mitotic activity in both elements. To date, only 6 cases of this uncommon neoplasm have been reported, corresponding to women over 70 years of age with ulcerated skin lesions. The authors describe the first sarcomatoid eccrine porocarcinoma in a 75-year-old male patient with a right hallux lesion, presenting a collision tumor with a mixed population of epithelial cells and a spindle cell angiosarcomatous mesenchymal component each expressing distinct and nonoverlapping morphologic and immunohistochemical features of epithelial and mesenchymal differentiation.