Metastasis of Rectal Signet Ring Cell Carcinoma to Typical Lipoma: A Rare Presentation of the Tumor-to-Tumor Metastasis Phenomenon.

Rectal signet ring cell carcinoma represents a rare subtype of colorectal adenocarcinoma known for its aggressive biological nature and poor prognosis. Although the co-occurrence of colorectal carcinoma with other tumors has been reported, the uncommon phenomenon of tumor-to-tumor metastasis, first described in 1930, remains rare. The most frequent donor neoplasms are lung or breast carcinomas, whereas cerebral meningiomas have been reported to be the most frequent recipient neoplasms. Here we report a case of a typical lipomatous tumor harboring metastatic signet ring cell rectal carcinoma. It is about a 42-year-old man diagnosed with rectal signet ring cell carcinoma and treated with concurrent radiotherapy and chemotherapy followed by an anterior resection and manual coloanal anastomosis with a temporary ileostomy. During the surgery, an abdominal wall lipoma was discovered and excised. A histopathological examination revealed infiltration of the fibro adipose tissue by a mucinous adenocarcinoma with a contingent of signet ring cells. The patient died 12 months after adjuvant chemotherapy due to peritoneal progression. To the best of our understanding, this represents the initial documented instance of tumor-to-tumor metastasis from rectal signet cell carcinoma to a conventional nonvascular lipoma. Consequently, even if one of these tumors appears clinically and radiologically benign, it is prudent to entertain the prospect of tumor-to-tumor metastasis. Thus, a comprehensive pathologic study of both tumors is highly recommended.

Vulvar Darier-Ferrand dermatofibrosarcoma: unusual localization of a rare tumor.

Dermatofibrosarcoma protuberans (DFSP) is a low-to-intermediate grade sarcoma of dermal origin that rarely presents in the vulva, typically occurring on the trunk of young to middle-aged adults. Even though it has a low potential for distant metastases, it often recurs locally. Therefore, surgical excision is the treatment of choice. We report a case of DFSP with fibrosarcoma transformation involving the vulva treated by large excision with tumor free margins followed by plastic reconstruction. Our aim is to highlight this rare disease and through literature evaluate the safety and efficacy of surgical treatment. Early recognition of this rare entity whose localization and the aggressive nature of the fibrosarcomatous component will be an issue in the surgical management.

Perforated Meckel's diverticulum in a very preterm baby revealed at birth.

Perforated Meckel's diverticulum (MD) in a preterm baby is very rare. We report a case of a very preterm baby, born at 29-week gestation, with a birth weight of 1400 g, admitted in the third hour of life to our intensive care unit (ICU) for respiratory distress syndrome with abdominal distention. An abdominal radiograph showed a pneumoperitoneum. Laparotomy revealed Meckel's perforation. The baby was discharged healthy at the age of 16 days. MD should be kept in mind as one cause of an acute abdomen in preterm neonates mimicking necrotizing enterocolitis. To our knowledge, our patient is the third reported case described in the literature and the first one revealed at birth.