Vincent M. Moretti

Early outcomes for malignant peripheral nerve sheath tumor treated with chemotherapy

Objectives:Malignant peripheral nerve sheath tumors (MPNST) are rare soft-tissue sarcomas with a tendency for recurrence and metastasis. Treatment using chemotherapy is controversial, but benefit with some agents has been described. This study aimed to analyze early survival outcomes using doxorubicin and ifosfamide chemotherapy for MPNST. Methods:Pathology records at our musculoskeletal tumor center were searched for patients with a new diagnosis of MPNST between 2003 and 2008. Treatment involved surgical resection, radiation, and chemotherapy with doxorubicin and ifosfamide. Ten patients met inclusion criteria, with mean age 40 years (range, 20–70). Four patients had metastatic disease on presentation. Four patients had neurofibromatosis type I (NF1). Results:Of 6 patients with nonmetastatic disease on presentation, 5 had no evidence of disease post-treatment. The sixth had positive margins after surgery and initially received no further treatment due to noncompliance. Three from this subgroup developed local recurrence, but none developed distant metastases and 1 died of disease at last follow-up. One- and 2-year disease-free survival (DFS) for this subgroup was 80% and 60%, respectively. One- and 2-year overall survival (OS) for the subgroup was 100%. Of 4 patients with metastatic disease on presentation, 2 had no evidence of disease post-treatment. One of these 2 developed local recurrence, but none from the subgroup developed new metastatic disease. Two of these 4 died of disease at last follow-up. One- and 2-year DFS for this subgroup was 100% and 50%, respectively. One- and 2-year OS was 75% and 50%, respectively. Two of the 4 patients presenting with metastatic disease had NF1. All 3 local recurrences and 2 of the 3 deaths in this study occurred in NF1 patients. Conclusions:For all patients, when combined with surgery and radiation, chemotherapy using doxorubicin and ifosfamide yielded 57% DFS and 80% OS at 2 years. NF1 patients appeared to have worse outcomes, with a statistically significantly lower DFS than non-NF1 patients. Limitations of this study include a small sample size, retrospective design, and use of different chemotherapy regimens.

Fibroma of tendon sheath in the knee: a report of three cases and literature review.

Fibroma of tendon sheath (FTS) is a rare and benign soft-tissue tumor. It is predominantly found in the fingers, hands, and wrists of young, adult males. We describe a series of three cases all presenting in the atypical knee location. We also review the literature on FTS, located both in the knee and elsewhere, looking for common clinical, imaging, and histologic patterns to help differentiate it from similar knee lesions. FTS typically presents as a painless, slow-growing, solid nodule. In the knee though, 71% of lesions present with pain/discomfort and 31% present with a palpable mass. Physical exam for knee FTS commonly reveals painful range of motion (50%), decreased range of motion (42%), and a palpable non-tender mass (33%). MRI of FTS usually reveals a well-defined soft-tissue mass, with low signal on T1, variable signal on T2, and variable enhancement. Histologically, the tumors are composed of a dense fibrocollagenous stroma with scattered spindle-shaped fibroblasts and narrow slit-like vascular spaces. Most FTS are removed by marginal excision, with 24% of lesions subsequently recurring. No lesion has ever metastasized. Despite its rarity, this lesion should be included in the differential diagnosis of a knee mass on physical exam or imaging, especially if it is painful, benign appearing, and present in a middle-aged male.

Spindle-cell hibernoma: a clinicopathologic comparison of this new variant.

Spindle-cell hibernoma is 1 of 4 histologic variants of hibernomas, which are rare lipomatous tumors distinguished from other lipomas by their brown fat component. This article presents a case of a spindle-cell hibernoma that developed in the groin of a 58-year-old man, and is 1 of only 5 known cases of spindle-cell hibernoma published in the scientific literature. Minimal information is available regarding the clinicopathologic characteristics of the 4 hibernoma variants: typical, lipoma-like, myxoid, and spindle-cell. Spindle-cell hibernoma is believed to be the rarest variant, accounting for approximately 2% of hibernomas. The spindle-cell variant predominantly develops in the fourth and fifth decades, with an average age at diagnosis of 42.5 years (range, 28-59 years). It has a male predilection of 4:1. Previously reported only in the posterior neck and scalp, the groin is now added to the sites of spindle-cell hibernoma occurrence. Our patients tumor demonstrated low-attenuation on computed tomography and contained moderately-attenuating internal septae. Histologically, in addition to the multivacuolated brown fat component common to all hibernomas, spindle-cell hibernoma has a spindle-cell element without vacuolization that is CD34 positive. No prior treatment details are available on this particular variant. Our patient was treated by marginal excision and was disease free through 13 months of follow-up.

Early pleomorphic hyalinizing angiectatic tumor: precursor or distinct lesion?

Early pleomorphic hyalinizing angiectatic tumor is a rare and recently described soft tissue lesion. Originally believed to be a precursor lesion to neoplastic pleomorphic hyalinizing angiectatic tumor, and possibly identical to hemosiderotic fibrohistiocytic lipomatous lesion/tumor, there have been recent suggestions that it is distinct from pleomorphic hyalinizing angiectatic tumor and is instead a reactive process. This article reports a case of a mass in the foot of a 45-year-old woman, which is 1 of only 15 published cases of early pleomorphic hyalinizing angiectatic tumor and is the first case to describe its radiographic appearance. Early pleomorphic hyalinizing angiectatic tumor predominantly develops in the fourth to sixth decades (average age, 45 years, range, 10-67 years). Females predominate 4 to 1. The foot/ankle is the most common site (67%). On magnetic resonance imaging (MRI), the mass appeared inhomogeneously dark on T1-weighted sequences and inhomogeneously bright on fat-suppressed T2-weighted sequences. Forty-four percent of resected lesions recur locally, but no early pleomorphic hyalinizing angiectatic tumor lesion has ever metastasized. These clinical characteristics of early pleomorphic hyalinizing angiectatic tumors closely mirror those of hemosiderotic fibrohistiocytic lipomatous lesions/tumors and are dissimilar to those for classic pleomorphic hyalinizing angiectatic tumors. Therefore, although the 3 entities share several histologic features, we believe early pleomorphic hyalinizing angiectatic tumor is equivalent to hemosiderotic fibrohistiocytic lipomatous lesion/tumor and is not a true precursor to classic pleomorphic hyalinizing angiectatic tumor.

Tendon Sheath Fibroma in the Thigh

Tendon sheath fibromas are rare, benign soft tissue tumors that are predominantly found in the fingers, hands, and wrists of young adult men. This article describes a tendon sheath fibroma that developed in the thigh of a 70-year-old man, the only known tendon sheath fibroma to form in this location. Similar to tendon sheath fibromas that develop elsewhere, our patients lesion presented as a painless, slow-growing soft tissue nodule. Physical examination revealed a firm, nontender mass with no other associated signs or symptoms. Although the imaging appearance of tendon sheath fibromas varies, our patients lesion appeared dark on T1- and bright on T2-weighted magnetic resonance imaging. It was well marginated and enhanced with contrast.Histologically, tendon sheath fibromas are composed of dense fibrocollagenous stromas with scattered spindle-shaped fibroblasts and narrow slit-like vascular spaces. Most tendon sheath fibromas can be successfully removed by marginal excision, although 24% of lesions recur. No lesions have metastasized. Our patients tendon sheath fibroma was removed by marginal excision, and the patient remained disease free 35 months postoperatively. Despite its rarity, tendon sheath fibroma should be included in the differential diagnosis of a thigh mass on physical examination or imaging, especially if it is painless, nontender, benign appearing, and present in men.