Introduction. Gastrointestinal angiosarcomas are rare and represent less than 1% of all gastrointestinal tract malignancies, with most occurring in the stomach and small intestine. Occurrence in the colorectal segments is considered extremely rare. Case Report. We describe the case of a 61-year-old male with multiple primary angiosarcomas of the colon who presented with fever and abdominal pain. The patient was initially hospitalized and treated as having an infectious disease. A multislice computed tomography (MSCT) scan revealed multiple soft tissue tumors in the region of the left iliopsoas and gluteus medius muscles. After developing hematochezia, a colonoscopy was performed which found an ulcerated tumor in the sigmoid colon. The small tissue biopsy taken during the procedure presented diagnostic difficulties and was given a preliminary diagnosis of gastrointestinal stromal tumor (GIST). Examination of the resected colon segment and surrounding fat tissue revealed four separate tumors. Microscopically, the tumors were composed of solid sheets of spindle and epithelioid neoplastic cells with prominent nucleoli and numerous mitotic figures and immunohistochemically positive for ERG, CD31, CD34, vimentin, and CD117, while negative for CK7, CK20, CD20, CD3, CD45, TTF-1, PAN-CK, ALK, Mpox, S-100, and DOG1, leading to the final diagnosis of multiple colonic angiosarcomas. The patient’s condition declined rapidly and he passed away from multiple organ failures 60 days after initial hospitalization. Conclusion. Both clinical and pathological diagnoses of colorectal angiosarcoma are challenging. Patients are present with nonspecific symptoms leading to mismanagement and late diagnosis. A definitive pathological diagnosis relies on immunohistochemical staining for endothelial markers. Misdiagnosis as poorly differentiated adenocarcinoma or GIST is possible in limited tissue biopsies.

SUMMARY Primary malignant melanoma of the urinary bladder is rare, with only 20 cases reported to date. We present a case of an 87-year-old woman with multiple comorbidities who presented with advanced urinary bladder neoplasm. Histopathologic analysis suggested melanoma of the urinary bladder. No previous or concurrent diagnosis of cutaneous melanoma was documented. The patient underwent transurethral resection of the tumor before and during hospitalization at our hospital but died shortly after due to widespread disease. Autopsy was not performed.

Objective: To present a case of a 6-month-old infant with melanotic neuroectodermal tumor of infancy (MNTI) in the upper arm. Clinical Presentation and Intervention: A 6-month-old female presented with a well-circumscribed lesion of the upper arm at the Children's Hospital Zagreb. A biopsy was performed and microscopy revealed 2 cell populations consisting of small neuroblastic cells and larger melanin-containing epithelial cells. An excisional biopsy performed 1 month later confirmed the initial diagnosis of MNTI, but the tumor had increased in size since the initial biopsy. After complete surgical excision the patient recovered well with no recurrence. Conclusion: The MNTI located in the upper arm was diagnosed on first biopsy and surgically excised completely. The patient recovered without recurrence in a follow-up of 2.5 years.

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.

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