Management of mucinous urachal neoplasm presenting as pseudomyxoma peritonei.

BACKGROUND: Mucinous neoplasms of the urachus are rare malignancies so that the physicians' index of suspicion for a timely and accurate diagnosis is low. Also, this disease may present with a wide variety of symptoms and signs. METHODS: Two patients with pseudomyxoma peritonei as the initial presentation of urachal mucinous adenocarcinoma were treated successfully. The medical literature regarding treatment options for this manifestation of the disease was searched. RESULTS: Two patients with large volume of pseudomyxoma peritonei originating in a mucinous urachal neoplasm were treated with cytoreductive surgery and perioperative intraperitoneal chemotherapy. Our first patient required two reoperations to palliate the accumulation of gross mucinous ascites. She died 11 years after diagnosis with progression of mucinous adenocarcinoma resulting in starvation. The second patient had ostomy closure with second look surgery at one year after definitive treatment; four small tumor nodules were seen and easily resected. The patient is currently without evidence of disease and has a normal quality of life. Seven prior manuscripts that report a single case of pseudomyxoma peritonei were reviewed to explore the full range of treatment options and survival for this rare condition. CONCLUSION: Cytoreductive surgery combined with perioperative intraperitoneal chemotherapy may be a new treatment option for mucinous urachal neoplasms presenting with pseudomyxoma peritonei. Other management strategies such as systemic chemotherapy seemed to hold little promise for this group of patients.

Thin-walled cysts as a pathognomonic CT finding in cystic mesothelioma.

AIM: Cystic mesothelioma is a rare disease that results in abdominal distention and poorly defined abdominal pain. Diagnosis has always been made by tissue biopsy rather than by radiologic studies. MATERIALS AND METHODS: Our experience with 7 patients with cystic mesothelioma includes 4 patients who had not had prior surgery before the performance of a high resolution CT scan. A special review of the radiology of these cases was performed in order to identify any pathognomonic signs of this disease. RESULTS: In all patients who did not have a distortion of the radiologic images (as a result of surgical interventions) prior to the performance of a high resolution CT scan at our institution, a pathognomonic thin-wall cystic structure located within the gelatinous appearing mass was observed. These thin-walled cysts were of variable size and preferentially located within the greater omentum, pelvis and beneath the right hemidiaphragm. CONCLUSION: Cystic mesothelioma can be diagnosed preoperatively by a high resolution abdominal and pelvic CT. The thin-walled cysts with great variation in size are located beneath the right hemidiaphragm, within the greater omentum and in the pelvis. No other disease with these radiologic findings has been identified.

Discordant histology of primary appendiceal adenocarcinoid neoplasms with peritoneal dissemination.

BACKGROUND: Adenocarcinoid is a rare appendiceal tumor that shows histologically both epithelial and neuroendocrine components. We observed that some patients have peritoneal dissemination, which shows adenocarcinoma but lacks the neuroendocrine histology. The objective of the present study was to quantitate these discordant histopathological findings and examine its clinical implication. METHODS: Twenty-six patients with peritoneal dissemination from primary appendiceal adenocarcinoid tumors underwent cytoreductive surgery and perioperative intraperitoneal chemotherapy. All resected specimens were individually submitted for histopathological examination and immunostaining with three neuroendocrine markers. The anatomic locations for peritoneal implants were prospectively recorded. The loss of the neuroendocrine tumor type in peritoneal implants was referred to as discordant feature of the adenocarcinoid tumor. Clinical and histopathological prognostic factors for survival were analyzed. RESULTS: In nine of the 26 patients (35%) with a primary adenocarcinoid of the appendix, a loss of the neuroendocrine immunochemical marker was noted in peritoneal implants. Discordant histology between the primary appendiceal adenocarcinoid and the peritoneal implants was statistically significantly associated with an improved survival (p = 0.0262), when patients were treated by cytoreductive surgery and perioperative intraperitoneal chemotherapy. CONCLUSIONS: Discordant histology of the primary appendiceal tumor as compared to the peritoneal lesions occurs frequently in patients with adenocarcinoid. An assessment of neuroendocrine markers in both primary and peritoneal lesions may help in the clinical assessment of this group of patients. Small numbers of patients were available for this study and the conclusions are therefore limited.

Prognostic indicators for patients undergoing cytoreductive surgery and perioperative intraperitoneal chemotherapy for diffuse malignant peritoneal mesothelioma.

BACKGROUND: This study evaluates clinical, radiological and histopathological prognostic indicators for survival of patients undergoing cytoreductive surgery and perioperative intraperitoneal chemotherapy for diffuse malignant peritoneal mesothelioma (DMPM). METHODS: Sixty-two consecutive patients with DMPM underwent cytoreduction and perioperative intraperitoneal chemotherapy at the Washington Cancer Institute. Twenty-six clinical, radiological and histopathological parameters were analyzed in univariate and multivariate analyses using overall survival as an endpoint. RESULTS: The overall survival was 79 months (range 1-143 months), with 1-, 3- and 5-year survival rates of 84%, 58% and 50%, respectively. The following 14 prognostic variables were significant for survival in the univariate analysis: gender (P = .045), peritoneal cancer index (P = .038), completeness of cytoreduction score (P = .010), interpretive CT findings of the small bowel and mesentery (P = .001), mesothelioma cell type (P < .001), mesothelioma nuclear size (P < .001), nuclear/cytoplasmic ratio (P < .001), mitotic count (P < .001), atypical mitosis (P < .001), chromatin pattern (P < .001), cellular necrosis (P < .001), perineural invasion (P = .037), stroma pattern (P < .001) and depth of invasion (P = .014). In the multivariate analysis, the only factor that was independently associated with an improved survival after cytoreduction and perioperative intraperitoneal chemotherapy was mesothelioma nuclear size. CONCLUSIONS: Mesothelioma nuclear size was the dominant factor determining overall survival in patients with DMPM. A histopathological staging system based on measurement of the nuclear size was proposed.

Prognostic significance of histomorphologic parameters in diffuse malignant peritoneal mesothelioma.

CONTEXT: Diffuse malignant peritoneal mesothelioma is currently regarded as a rare and lethal primary tumor arising from the peritoneal membrane. In the past, treatment plans with variable combinations of surgery and systemic chemotherapy were associated with a median survival of approximately 1 year. Standardized treatments using cytoreductive surgery and perioperative intraperitoneal chemotherapy have extended this survival. OBJECTIVE: To critically analyze the prognostic significance of histomorphologic parameters as a determinant of survival. DESIGN: Sixty-two consecutive patients with diffuse malignant peritoneal mesothelioma in whom data were prospectively accumulated were retrospectively analyzed by 14 different histomorphologic parameters. The influences of these pathologic characteristics on survival were critically statistically evaluated. RESULTS: In a univariate analysis, histologic type, nuclear/nucleolar size, stroma, depth of invasion into the bowel, atypical mitoses, mitotic index, necrosis, lymph node involvement, and chromatin patterns were found to be significant. In the multivariate analysis, histologic type and nuclear/nucleolar size remained as determinant histomorphologic characteristics. Use of biphasic/sarcomatoid histologic type as a poor prognostic characteristic was limited in that only 8% of patients showed this histology. CONCLUSIONS: Histomorphologic parameters carry prognostic significance in predicting the survival of patients with diffuse malignant peritoneal mesothelioma when treated in a standardized fashion using cytoreductive surgery and perioperative intraperitoneal chemotherapy. Nuclear/nucleolar size was found to be a reliable histomorphologic assessment available to assess prognosis in these patients.

Clinical perspective on desmoplastic small round-cell tumor.

Rare diseases are often associated with uninformed medical decisions and poorly executed treatments because of inexperience of the physicians. Desmoplastic small round-cell tumor is a rare disease that is a form of peritoneal surface malignancy usually affecting young males, with a mean survival of 29 months. In order to begin to build a more knowledgeable clinical pathway all 7 patients treated at the Washington Hospital Center were studied and compared to patients described in the medical literature. Clinical and pathological data, tumor distribution, cytoreductive surgery, completeness of cytoreduction and survival were recorded and analyzed. The first most common symptoms were pain, increased abdominal girth and palpable abdominal mass in our patients and in the literature review. The overall survival did not improve with cytoreductive surgery plus intraperitoneal chemotherapy (mean survival 32 months); however, 2 long-term survivors who responded to systemic chemotherapy of 55 and 101 months were recorded. The latter may be the longest survivor reported in the literature. No consistent response to chemotherapy was observed in our patients or in any literature review. Complete surgical removal of this malignancy did not correlate with survival in our patients. The absence of improved survival of our aggressively treated patients as compared to the literature was thought to be a consequence of an advanced stage of the disease. A new comprehensive approach that uses complete clearing of cancer by surgery and perioperative systemic and perioperative intraperitoneal chemotherapy as early as is possible in the natural history of the disease emerged as goals for future management.

Glomus tumor of the duodenum: a case report.

We describe a rare case of glomus tumor of the duodenum. The tumor was detected in a 46-year-old man being investigated for episodes of gastrointestinal bleeding. The excised specimen showed a 2.3 x 1.5 x 1.5 cm gray-tan tumor involving the mucosa and the submucosa. The overlying mucosa was focally ulcerated. Histologically, the tumor had a solid pattern of sharply demarcated, round glomus cells with prominent pericytoma-like vessels of varying sizes. The neoplastic cells stained for vimentin, smooth muscle actin, and focally for synaptophysin. These histologic and immunohistochemical features are consistent with a diagnosis of glomus tumor of the duodenum.

Clinically aggressive pseudomyxoma peritonei: a variant of a histologically indolent process.

BACKGROUND: Three distinct morphologic types of pseudomyxoma peritonei syndrome have been defined: disseminated peritoneal adenomucinosis (DPAM), peritoneal mucinous carcinoma (PMCA), and a hybrid morphologic type. Prognosis is best in patients with DPAM; unfortunately, some patients with DPAM succumb to a rapidly progressive disease process. METHODS: We identified a subset of 11 patients with a histopathology of DPAM but a clinical course showing an invasive disease process. As a comparison group, from a database of 501 patients with pseudomyxoma peritonei, we selected 22 age- and sex-matched controls with a DPAM histology who are alive with no evidence of disease. Clinical factors were identified for comparison of case and control groups. Expression of mucin antigens, mucin (MUC)1 and MUC2, were evaluated using immunohistochemistry. RESULTS: The study group consisted of 11 patients (five men and six women), with a median survival of 52.2 months (SD 7.46) and a 31% 5-year survival. All 22 matched control cases (10 men and 12 women) are alive and disease-free. Clinical data on the study and control groups including co-morbidity were similar. No significant difference in the expression of MUC1 (P = 0.74, Fisher's exact test) or MUC2 (P = 0.34, Fisher's exact test) was demonstrated between groups. CONCLUSIONS: Further investigation of pseudomyxoma peritonei at a molecular and genetic level may help to formulate a more comprehensive classification.

Prognostic assessment of gastrointestinal stromal tumor.

The term "gastrointestinal stromal tumor" (GIST) has been applied to a collection of distinctive mesenchymal tumors occurring within the human gastrointestinal tract. As new drug therapy becomes available, data regarding the natural history of these unusual tumors are necessary to provide selection factors for treatment. Ninety-eight patients had light microscopy compatible with GIST at a single institution from 1989 to 2000. After immunostaining with c-kit and histopathologic review, 69 were judged to be GIST. All prognostic indicators were determined for gastric GIST, intestinal GIST, and all locations combined. The location of the GIST did not have a significant impact on survival. Clinically, tumor size, peritoneal cancer index, and completeness of cytoreduction had a significant impact on prognosis for GIST at all locations. Pathologically, cytologic atypia, necrosis, invasion and number of mitoses were significant prognostic indicators for GIST. Criteria to separate three pathologic groups of GIST according to the tumor size and the mitotic count were useful to evaluate the tumor behavior; in the borderline pathologic group invasion and cytologic atypia were statistically significant prognostic criteria. The cell phenotypes, as determined by immunostains, correlated with the prognosis of gastric GIST but not intestinal GIST. A correlation between the immunostain Ki-67 but not CD-34 or desmin and the prognosis was observed. It is possible to select clinical and pathologic parameters of GIST that impact on prognosis. Invasion and necrosis help to determine the prognosis with borderline tumors. The immunostain Ki-67 correlated with the prognosis and may be helpful to assess prognosis when dealing with small biopsy specimens.

An unusual case of multiple papillary fibroelastoma, review of literature.

Primary neoplasms of the cardiac valves are extremely rare. However, papillary fibroelastoma is the third most common primary tumor of the heart [Ann Thorac Surg 52 (1991) 1127]. These tumors can be found anywhere in the heart, but most commonly involve the cardiac valves [Ann Thorac Surg 52 (1991) 1127; McAllister HA, Fenoglio JJ. Tumors of the cardiovascular system. In: Atlas of tumor pathology, 2nd series, vols. 1-3. Washington (DC): Armed Forces Institute of Pathology; 1978. p. 20-5]. Most papillary fibroelastomas do not cause symptoms and are usually incidental findings by routine echocardiography or at autopsy. However, early diagnosis of this condition is important, since it represents a surgically correctable cause of systemic emboli, stroke, myocardial infarction, and sudden cardiac death [Ann Thorac Surg 52 (1991) 1127; Ann Thorac Surg 68 (1999) 1881; J Am Soc Echocardiogr 9 (1996) 353; Tex Heart Inst J 22 (1995) 327; Tex Heart Inst J 26 (1999) 298]. The echocardiographic findings should be confirmed by histology, since the clinical differential diagnosis includes myxoma, vegetation, thrombi, lipoma, and pseudopapillary fibroelastoma [Tex Heart Inst J 26 (1999) 298; J Am Soc Echocardiogr 11 (1998) 92; J Natl Med Assoc 87 (1995) 68]. Review of the literature reveals that multiple papillary fibroelastomas are extremely rare [Am Heart J 125 (1993) 1443; J Am Soc Echocardiogr 7 (1994) 315; Ann Thorac Surg 48 (1989) 119]. Li Manduri et al. [J Am Soc Echocardiogr 7 (1994) 315] reported multiple masses on the tricuspid valve, the larger of which was 1 cm in diameter. De Virgilio et al. [Ann Thorac Surg 48 (1989) 119] reported a case of multiple 1-cm papillary fibroelastomas located on mitral valve, left ventricular outflow tract, and along septum. We report an unusual case of multiple papillary fibroelastomas in a woman, who initially was admitted because of a shortness of breath and recent cerebrovascular accident.