What is your diagnosis?

A 79-year-old Caucasian woman presented to our outpatient clinic with a freezer bag containing an irregularly shaped mass that had been spontaneously defecated 3 hours previously (Fig. 1). The patient reported a recent history of constipation and blood in her stool. Her past medical history included hypertension, hypothyroidism, obesity, and metabolic syndrome. A physical examination did not reveal signs of weight loss or anaemia. Histopathology of the mass revealed a tumour composed of sheets containing densely packed, elongated spindle-shaped cells with cigar-shaped centrally-located nuclei and abundant fibrillar eosinophilic cytoplasm. Mitotic figures were observed. There were also foci of haemorrhage, cystic degeneration, and necrosis (Figs. 2, 3). Immunohistochemical staining indicated that the tumour expressed SMA, desmin, and h-caldesmon and was negative for CD117 (c-KIT), CD34, and DOG-1 (Fig. 4).
Pierre de Mathelin1, Felix Lerintiu2, Jean-Baptiste Delhorme1 1Hôpitaux Universitaires de Strasbourg, France 2Hôpitaux Civils de Colmar, France
Answers should be sent to the Editorial Office until 31.03.2024. The correct answer will be announced in the next issue of the Polish Journal of Pathology.