Perivascular epithelioid cell tumor (PEComa) is a rare entity, characterized as a mesenchymal tumor with coexpression of melanocytic and smooth muscle markers. The involvement of the gastrointestinal tract is described in up to 100 cases in the English literature. Rectal PEComas are even more uncommon, with only 10 previously described cases. We present the case of a 62-year-old man with rectal PEComa with some unusual features, such as gastrointestinal stromal tumor–like CD117 positivity and HMB45 (human melanoma black-45)–positive multinucleated giant tumor cells. After 12 months' follow-up, the patient is alive with no radiologic, endoscopic, or histologic evidence of disease recurrence.

Paragangliomas of the head and neck are uncommon tumors arising from parasympathetic ganglia. Paragangliomas are mostly asymptomatic and may manifest as palpable mass of neck. The morphologic features are non-specific and comparable to the other neuroendocrine tumors. Most of hereditary cases are associated with alterations in genes of succinate dehydrogenase (SDH). SDHA and SDHB immunohistochemistry is considered as reliable screening method to detect tumors with genetical alterations. Of note, SDHB mutated paragangliomas have the highest risk of local recurrence, distant metastasis and the development of other tumor phenotypes, which are associated with mutation. Therefore, active surveillance of patients and early surgical treatment are essential. In contrast, SDHB mutated head and neck paragangliomas was considered as completely benign tumors, although, the latest literature describes more controversial cases, which may increase awareness. Here, we present a rare case of 21 years old female with asymptomatic neck paraganglioma, which was unexpectedly diagnosed after pathological and immunohistochemical testing of removed thyroid gland and showed unusual immunohistochemical variation for SDH mutation.

BackgroundMetastatic involvement of the penis in cases of rectal cancer is exceptionally rare condition. Our clinical case report and review of the literature will contribute in complementing currently limited data on penile metastasis from rectal cancer.Case reportWe report a case of a 64-year-old male diagnosed with penile metastasis from rectal cancer. The patient was treated with neoadjuvant chemoradiotherapy followed by total mesorectal excision (TME). However, penile metastasis developed 3 years later, clinically presenting as penile pain and solid formations along the entire length of the penis with visible tumor in the head of the penis. The amputation of penis was performed, and adjuvant chemotherapy was prescribed. The patient survived only 6 months.ConclusionPenile metastasis from rectal cancer in most cases is a lethal pathology that indicates wide dissemination of oncological disease and has a very poor prognosis. Aggressive surgical treatment is doubtful in metastatic disease as this will negatively affect the quality of life.

Glomus tumor is a rare benign mesenchymal tumor, mostly found in acral skin or superficial soft tissues, but it can occur in other locations. Glomus tumors in different locations share similar histological and immunohistochemical characteristics, although some aberrant features can be identified. We report a case of 41 year-old male with gastric glomus tumor, preoperatively diagnosed as CD117 negative gastrointestinal stromal tumor. Apart from the rare location, glomus tumor showed some other unusual features -peritumoral polytypic plasmacytosis and florid mesothelial hyperplasia. Although gastric glomus tumors are rare, they should be included in differential diagnosis of submucosal gastric tumors.