Mesenteric desmoid tumor 19 years after radiation therapy for testicular seminoma

Unusual finding after treatment for testicular cancer

In the context of a post-treatment testicular germ cell tumour, an abdominal lesion found on surveillance CT studies led to a differential diagnosis, including recurrent germ cell tumour. We report the case of a 48-year-old man who was noted to have a new interval soft tissue lesion on a surveillance CT scan, 5 years after initial orchidectomy and chemotherapy. Excision of this lesion and histopathological review revealed an intra-abdominal desmoid.

Aggressive fibromatosis

Aggressive (deep or desmoid-type) fibromatoses are locally infiltrative collagen-forming tumours with potential for recurrence but not metastasis. They exert their clinical effects primarily in relation to location and have variable biological behaviour. In sporadic cases there are somatic mutations in the β-catenin (CTNNB1) gene on 3p21, resulting in immunohistochemically demonstrable overexpression in nuclei. Fibromatosis in patients with familial adenomatous polyposis (FAP) harbours inactivating germline mutations in the desmoid region of the adenomatous polyposis coli (APC) gene on 5q21-q22. The differential diagnosis includes other myofibroblastic lesions, perineurioma, low grade fibromyxoid sarcoma and, in the abdomen, gastrointestinal stromal tumour and liposarcoma with 'low-grade' dedifferentiation. The primary management is surgical, though some desmoids cease to grow and can be watched. Other therapies have a role in stabilising growth or shrinking tumours. Although no single therapy is effective in all cases, available modalities including irradiation, hormonal therapy, chemotherapy, and receptor tyrosine kinase inhibition can be of value in appropriate clinicopathological subgroups.

Subsequent intra-abdominal fibromatosis mimicking recurrent gastrointestinal stromal tumor

Abstract

Intra-abdominal fibromatosis (IAF) commonly develops in patients who had abdominal surgery. In rare instances, it occurs subsequent to gastrointestinal stromal tumor (GIST). This special situation has clinical significance in imatinib era. About 1000 patients with GIST in our institution from 1993 to 2010 were re-evaluated based on their clinical and pathological data, the treatment strategies and the follow-up information. We identified 2 patients who developed IAF after GIST resection. Patient 1 was a 54 year-old male and had 5 cm × 4.5 cm × 3.5 cm jejunal GIST excised on February 22, 1994. Three years later, an abdominal mass with 7 cm × 6 cm × 3 cm was identified. He was diagnosed as recurrent GIST from clinical point of view. After excision, the second tumor was confirmed to be IAF. Patient 2 was a 45-year-old male and had 6 cm × 4 cm × 3 cm duodenal GIST excised on August 19, 2008. One year later, a 4 cm mass was found at the original surgical site. The patient refused to take imatinib until the tumor increased to 8 cm six months later. The tumor continued to increase after 6 months’ imatinib therapy, decision of surgical resection was made by multidisciplinary team. The second tumor was confirmed to be IAF with size of 17 cm × 13 cm × 11 cm. Although IAF subsequent to GIST is very rare, it is of clinical significance in imatinib era as an influencing factor for making clinical decision.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1076715989961803

Intra-abdominal desmoid tumor following retroperitoneal lymph node dissection for testicular germ cell tumor

In the testicular cancer post-treatment setting a rapidly growing retroperitoneal mass leads to a differential diagnosis including recurrent germ cell tumor, residual mature teratoma, or sarcomatoid degeneration. We report the case of a 27-year-old man with a large abdominal mass occurring in the setting of a mixed germ cell tumor after radical orchiectomy with primary chemotherapy followed by retroperitoneal lymph node dissection. Surgical excision of this mass followed by pathological review revealed an intra-abdominal desmoid tumor. Fluorescence in situ hybridization (FISH) for isochromosome 12p failed to demonstrate a germ cell tumor origin. This is the fourth such case of an intra-abdominal desmoid tumor after retroperitoneal lymph node dissection for testicular cancer in the urologic literature. This case highlights the need for careful consideration of a desmoid tumor when a rapidly growing spindle cell tumor is encountered in a post-treatment testis cancer patient.

Mesenteric desmoid mimicking recurrent testicular cancer

The detection of a solid abdominal mass after surgery for testicular cancer most frequently represents metastatic disease. We report an unusual case of mesenteric desmoid tumor presenting after retroperitoneal lymph node dissection for metastatic testicular cancer. To our knowledge, there are no similar reports in the radiology literature.

Comprehensive genetic and endoscopic evaluation may be necessary to distinguish sporadic versus familial adenomatous polyposis–associated abdominal desmoid tumors

BACKGROUND

There are limited data regarding how many patients with desmoid tumors actually represent cases with underlying familial adenomatous polyposis.

METHODS

A proband presenting with desmoid tumors and several of the family members underwent a detailed family history, genetic (adenomatous polyposis coli [APC] gene sequencing), and upper and lower endoscopic evaluation.

RESULTS

The proband's initial diagnosis was of a sporadic desmoid tumor. Colonoscopy was entirely normal. However, on subsequent esophagogastroduodenoscopy, several gastric polyps were found. The proband's mother subsequently underwent colonoscopy and was found to have multiple colon adenomas. On genetic analysis, a deletion of "T" was identified at codon 2645 of the APC gene in the proband. The proband's mother had a normal APC protein truncation test result. However, on full gene sequencing, the mother was found to harbor the same APC gene mutation.

CONCLUSION

A detailed family history and endoscopic and genetic evaluations for patients with desmoid tumors are vital because they may be the sentinel presentation of familial adenomatous polyposis. If confirmed in larger studies, APC full gene sequencing and upper and lower gastrointestinal tract evaluation may need to be part of standard evaluation of patients with abdominal desmoid tumors.