Metastatic renal mucinous tubular and spindle cell carcinoma. Atypical behavior of a rare, morphologically bland tumor.

Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare, distinctive renal neoplasm characterized by an admixture of cuboidal cells in tubules and sheets of spindle cells, typically with low-grade nuclei and a myxoid or mucinous background. It is characteristically of low malignant potential, and only rare metastatic cases have been reported. We describe a case in which the patient presented with extensive regional and distant metastases, but both primary and metastatic tumor showed the typical histomorphology of bland cuboidal or spindle cells lacking pleomorphism, mitoses, and necrosis. Almost all previous cases of metastatic MTSCCs have shown nuclear atypia or sarcomatoid morphology of the primary tumor; and metastatic renal MTSCC in which the primary neoplasm does not display atypical features is exceptional, serving to highlight that these rare tumors can behave aggressively even with "indolent" histological appearances.

Diagnostic Performance of Magnetic Resonance Enterography Disease Activity Indices Compared with a Histological Reference Standard for Adult Terminal Ileal Crohn's Disease: Experience from the METRIC Trial.

BACKGROUND AND AIMS: The simplified magnetic resonance enterography [MRE] index of activity [sMARIA], London, and 'extended' London, scoring systems are widely used in Crohn's disease [CD] to assess disease activity, although validation studies have usually been single-centre, retrospective, and/or used few readers. Here, we evaluated these MRE indices within a prospective, multicentre, multireader, diagnostic accuracy trial. METHODS: A subset of participants [newly diagnosed or suspected of relapse] recruited to the METRIC trial with available terminal ileal [TI] biopsies was included. Using pre-specified thresholds, the sensitivity and specificity of sMARIA, London, and 'extended' London scores for active and severe [sMARIA] TI CD were calculated using different thresholds for the histological activity index [HAI]. RESULTS: We studied 111 patients [median age 29 years, interquartile range 21-41, 75 newly diagnosed, 36 suspected relapse] from seven centres, of whom 22 had no active TI CD [HAI = 0], 39 mild [HAI = 1], 13 moderate [HAI = 2], and 37 severe CD activity [HAI = 3]. In total, 26 radiologists prospectively scored MRE datasets as per their usual clinical practice. Sensitivity and specificity for active disease [HAI >0] were 83% [95% confidence interval 74% to 90%] and 41% [23% to 61%] for sMARIA, 76% [67% to 84%] and 64% [43% to 80%] for the London score, and 81% [72% to 88%] and 41% [23% to 61%] for the 'extended' London score, respectively. The sMARIA had 84% [69-92%] sensitivity and 53% [41-64%] specificity for severe CD. CONCLUSIONS: When tested at their proposed cut-offs in a real-world setting, sMARIA, London, and 'extended' London indices achieve high sensitivity for active TI disease against a histological reference standard, but specificity is low.

A rare solitary and endobronchial pulmonary hyalinising granuloma requiring bilobectomy.

Pulmonary hyalinising granuloma is a very rare disease often presenting as multiple smooth rounded nodules within the lung parenchyma and mimicking metastatic disease. Solitary pulmonary hyalinising granuloma is an even rarer subgroup, and to our knowledge, there have been no endoluminal pulmonary hyalinising granulomas reported. A 36-year-old female non-smoker with no significant past medical history presented with a persistent cough and was found to have a right lower lobe bronchial lesion causing lower lobe obstruction. After multiple failed attempts at tissue diagnosis from both percutaneous and endobronchial biopsies, and with worsening haemoptysis, the patient underwent a right thoracotomy and lower bilobectomy. The histopathology was reported as a solitary endobronchial pulmonary hyalinising granuloma. Although benign in nature, tissue diagnosis can be difficult in these lesions, especially when presenting as a solitary mass in a central location. This report demonstrates that these lesions can also be found endobronchially necessitating parenchymal resection for diagnosis and obstructive symptoms.

A rare cause of rectal bleeding masquerading as proctitis.

BACKGROUND AND AIMS: Diffuse cavernous haemangioma of the rectum (DCHR) is a rare benign vascular neoplasm that affects mainly young adults and can present with rectal bleeding or massive haemorrhage. We report a case of DCHR masquerading as proctitis which was diagnosed many years ago following colonoscopy. This is the first case where the DCHR was resected with subsequent formation of a colonic J pouch versus conventional colo-anal anastomosis in order to maintain good bowel function. METHOD: Clinical case report including a review of current literature regarding DCHR. RESULTS: This is one of few cases of DCHR reported that was initially misdiagnosed as proctitis. CONCLUSIONS: Awareness of this rare condition is important when investigating patients presenting with rectal bleeding to prevent unnecessary treatment and delay surgery. Prompt intervention is necessary to prevent severe rectal haemorrhage.