This report presents the case of primary Mucoepidermoid Carcinoma of the skin on the leg of a 74-year-old man. The epidemiological data of the neoplasm are examined, and the morphological picture and immunophenotypic profile are compared with those of the homologous tumor of the salivary glands. According to the scoring system of this type of tumor, our case is classified as low-grade.

Myasthenia gravis (MG) is frequently complicated by respiratory insufficiency, which is known as an MG crisis. It can appear as the initial presenting symptom of myositis-MG overlap. Here we report a case of a 67-year-old woman with previously underdiagnosed MG, who presented with acute respiratory insufficiency. A bulky mass in the right lung was pathologically suspected to be a lymphoepithelioma-like carcinoma of the thymus. Due to high expression of programmed death-ligand 1 (PD-L1) (70%-80%) on the tumor, the immune checkpoint inhibitor (ICI) pembrolizumab was administered as second-line therapy. However, the patient died of ICI-induced myocarditis, which was confirmed by autopsy. Immunohistochemistry showed an overexpression of PD-L1 on the myocardial sarcolemma as well as the diaphragm. PD-L1 overexpression on the diaphragm might have contributed to the pathogenesis of myositis-MG overlap with acute respiratory insufficiency.

A case of cutaneous myoepithelioma arising in the plantar area in a 56-year-old man is presented. The morphology and immunohistochemical profile are described. The literature on the subject is analyzed.

Cystic lymphangiomas are extremely rare benign vascular neoplasms generally found in childhood. Thought to arise from obstructed lymphatic channels during development, but may also arise secondary to trauma, inflammation, malignancy, and surgery or radiation exposure. They are usually seen in the head and neck or axillary region, and rarely in the abdominal cavity with only 1% occurring in the retroperitoneum. These are typically asymptomatic lesions incidentally identified by computer tomography, magnetic resonance imaging or ultrasound. Complete surgical resection with histologic confirmation of the diagnosis is the treatment of choice.
We present a case of a 27-year-old woman with multiple cystic lymphangiomas in retroperitoneum, discovered incidentally by ultrasound during pregnancy.

We report a patient with polymorphous adenocarcinoma of the breast. Polymorphous adenocarcinoma of the breast is a rare tumour that corresponds to polymorphous adenocarcinoma in the salivary gland. The tumour consisted of a unimorphous population of one type of neoplastic cells with hyperchromatic, pleomorphic nuclei. Neoplastic cells were arranged in various architectural patterns including solid pattern, trabecular pattern and single “Indian-file“ arrangement with myxoid stroma in between. Tumour cells were negative for Estrogen, Progesterone, Her-2/neu, Smooth Muscle Actin, Cytokeratin 5/6, Cytokeratin 7, Synaptophysin and Chromogranin, while Cytokeratin AE1/AE3 (Pankeratin), BCL2 and E-cadherin were positive and p63 partially positive. Polymorphous adenocarcinoma is a rare and salivary gland-type tumour with only three cases reported up to date. To the best of our knowledge this is the fourth case of a polymorphous adenocarcinoma of the breast reported in the english literature.

Inflammatory myofibroblastic tumor (IMT) is a rare soft-tissue neoplasm which has been described in a variety of locations. In the urogenital system, it occurs mainly in the bladder and the kidney. IMT arising from the ureter is exceedingly rare. We report an exceptional case of IMT arising from the ureteric submucosa in a three-year-old female child. The patient presented with pan-hematuria and no other symptoms. Urinalysis revealed numerous red blood cells, culture was negative for infection. A CT Urogram showed the lesion was involving most of the ureter. A left radical nephroureterectomy was performed, and she has remained well to date. Ureteral IMT is extremely rare and often asymptomatic, which can result in a delayed diagnosis. Radical excision is the best therapeutic approach with excellent survival outcomes.