Tran TA, Holloway RW, Finkler NJ.

Department of Pathology, Florida Hospital Orlando, Orlando, Florida 32803, USA. trannguyentienanh@hotmail.com

Abstract

Atypical/florid mesothelial hyperplasia associated with another neoplastic process is not an infrequent phenomenon and has been reported in a variety of tumors. In those instances, the mesothelial proliferation might create a misdiagnosis of metastatic carcinoma but seldom raises the possibility of a well-differentiated mesothelioma seeded by metastatic neoplastic cells. Herein, we report the case of a 40-year-old woman originally diagnosed with exuberant atypical mesothelial hyperplasia after an diagnostic laparoscopy. The subsequent operation, however, demonstrated a mucinous neoplasm of the appendix with involvement of the peritoneal cavity in the form of peritoneal mucinous carcinomatosis as well as metastases to the uterine serosa and adnexal surfaces. Microscopic analysis revealed an appendiceal adenocarcinoma with signet-ring-cell features that has metastasized to a diffuse well-differentiated mesothelioma of the peritoneal cavity. In many areas, the atypical mesothelial proliferation is indistinguishable from florid mesothelial hyperplasia. The true nature of the mesothelial proliferation was only confirmed after extensive additional sampling, which showed unequivocal stromal invasion. To the best of our knowledge, this is the first report of a metastatic appendiceal mucinous adenocarcinoma to a well-differentiated diffuse mesothelioma of the peritoneal cavity. Although commonly associated with atypical/ florid mesothelial hyperplasia, a carcinoma can rarely metastasize to a well-differentiated mesothelioma, which can pose significant diagnostic difficulties because it can mimic a reactive process. This unusual case report expands the spectrum of mesothelial proliferation in conjunction with a malignant neoplasm and serves to remind pathologists that such a concomitant occurrence exists.

Glossary

adenocarcinoma

(add-en-o car-sin-o-muh). Cancer that starts in the glandular tissue, such as in the ducts or lobules of the breast.

neoplasm

(nee-o-plas-um) an abnormal growth (tumor) that starts from a single altered cell; a neoplasm may be benign or malignant. Cancer is a malignant neoplasm.

hyperplasia

(hy-per-PLAY-zuh) too much growth of cells or tissue in a specific area, such as the lining of the breast ducts or the prostate. By itself, hyperplasia is not cancerous, but when there is a lot of growth or the cells are not like normal cells, the risk of cancer developing is greater.

cell

the basic unit of which all living things are made. Cells replace themselves by splitting and forming new cells (mitosis). The processes that control the formation of new cells and the death of old cells are disrupted in cancer.

carcinoma

(car-sin-o-ma) a malignant tumor that begins in the lining layer (epithelial cells) of organs. At least 80% of all cancers are carcinomas.

atypical

(A-tip-uh-kul) not usual; abnormal. Often refers to the appearance of cancerous or precancerous cells. (See also hyperplasia.)

mesothelioma

a tumor derived from mesothelial tissue, such as the peritoneum (lining the abdomen) or pleura (lining the lungs). More on mesothelioma.

peritoneal

(pair-uh-tuh-nee-al) the serous membrane that lines the cavity of the abdomen. (More on Peritoneal Mesothelioma.)

Yan T, Sugarbaker P.

Peritoneal Surface Malignancy Program, Washington Cancer Institute, Washington Hospital Center, Washington, DC 20010, USA.

Abstract

Aims and Background: Diagnostic technologies which penetrate the abdominal wall in an attempt to definitively diagnose an intraabdominal malignancy by biopsy can contaminate the abdominal wall by cancerous cells. With follow-up these entrapped cancer cells may progress as an abdominal wall recurrence of the disease process. Frequently, laparoscopy is the definitive diagnostic study which results in the abdominal wall cancer progression.

Methods: We examined recurrences within the abdominal wall and attempted to establish a surgical approach to this problem which would maximize a functional result and minimize the incidence of disease persistence within the abdominal wall.

Results: Eighteen patients with abdominal wall recurrence were studied. Laparoscopy port sites resulted in the abdominal wall disease in eight patients, in four the recurrence was at a previous ostomy site, in three it was in a Pfannenstiel incision and in three it was in a McBurney incision site. All of these patients were treated by total resection of the rectus abdominis muscle. This resulted in a complete removal of visible disease that was dissecting along the fibers of the rectus abdominis muscle.

Conclusions: No patients required reoperation for abdominal wall hernia and mesh repair was not used in any of these patients. Disease control within the abdominal wall has been excellent.

Glossary

resection

surgery to remove part or all of an organ or other structure.

recurrence

cancer that has come back after treatment. Local recurrence is when the cancer comes back at the same place as the original cancer. Regional recurrence is when the cancer appears in the lymph nodes near the first site. Distant recurrence is when it appears in organs or tissues (such as the lungs, liver, bone marrow, or brain) farther from the original site than the regional lymph nodes. Metastasis means that the disease has recurred at a distant site.

ostomy

(os-to-me) a general term meaning an opening, especially one made by surgery. See also colostomy, ileostomy, urostomy, and tracheostomy.

cancer

malignancy; a group of diseases typified by abnormal, generally out-of-control, cell growth.

biopsy

(buy-op-see) the removal of a sample of tissue to see whether cancer cells are present. There are several kinds of biopsies. In some, a very thin needle is used to draw fluid and cells from a lump. In a core biopsy, a larger needle is used to remove more tissue.

peritoneal

(pair-uh-tuh-nee-al) the serous membrane that lines the cavity of the abdomen. (More on Peritoneal Mesothelioma.)