WHAT IS THIS HEMORRHAGIC TUMOR?
A debilitated wheelchair-bound 67-year-old man developed an abrupt-onset painful hemorrhagic tumor over the left pre-tibial surface, which rapidly grew and developed over several months. There was no history of trauma or other injury. The patient was unable to give a reliable history, but his caretakers noted increasing pain with full range of motion and bleeding from the base of the tumor. His past history is significant for squamous cell carcinoma of the lung, hypothyroidism, and a longstanding history of cardiac disease. Current medications include warfarin and multiple others.
Physical examination revealed a 4.8 cm x 5.5 cm hemorrhagic boggy tumor, which was fixed and tender to palpation. The base of the tumor was indurated and edematous. There was unclear evidence of ulceration or purulence, although there was prominent granulation tissue over the center. There was no popliteal adenopathy or vascular compromise. The patient was confined to a wheelchair and unable to complete the remainder of the physical examination, although no other lymphadenopathy or hepatosplenomegaly was detected. No other cutaneous tumors were noted.
What Is Your Diagnosis?
Diagnosis: Malignant Fibrous
HistiocytomaMalignant fibrous histiocytoma (MFH) is a cancerous fibrohistocytic tumor that can originate in either bone or soft tissues. While it is among the most common types of soft tissue tumors found in adults, it is rarely found in children, making up only a small percentage of all soft tissue sarcomas, which as a group account for only 1% of new cancer cases in children each year.1
Malignant fibrous histiocytoma often presents as an asymptomatic nodule, most often on the extremities, although it can appear anywhere on the body. There can be invasion of the lymph nodes and locally to bone, but most commonly it metastasizes to the lung (90%), bone (8%) and liver (1%). The tumor has been reported to develop in the kidney,2 spleen,3 oral cavity,4 spermatic cord5 and even the thoracic aorta.6
Several theories exist regarding both histiocytic and primitive mesenchymal cell theories of origin. In general, the tumor contains both fibroblastlike and histiocytelike cells in varying proportions, with spindle and basaloid cells in a storiform arrangement.
Multiple histologic subtypes have been described including: (1) storiform/pleomorphic (most common); (2) myxoid; (3) giant cell; (4) inflammatory (usually retroperitoneal); and (5) angiomatoid (often located more superficially than other varieties).
In addition, an associated genetic abnormality on the short arm of chromosome 13 has been investigated but not confirmed.7 Losses of 13q12-q14 or 13q21 were observed in a large proportion of tumors (17 cases), suggesting that a gene localized in this region could act as a tumor suppressor gene. Losses of 11q23, 2q32, 11p13, 10p, 1q4, 9p2, 16q12, 4q3, 10q25, 3p23, 2p24 and 12p were also recurrently observed.7 Another study evaluated a correlation of local recurrence and metastases, which were more common in association with 19p+ than without. Metastasis was more common with 19p+ tumors in high-risk patients, suggesting fewer relapses in tumors associated with ring chromosomes. This finding might label 19p+ as an independent marker of unfavorable outcome in MFH.8
MFH has become widely regarded as the most common soft-tissue sarcoma of adulthood and is still accepted widely as a discrete clinicopathologic entity. Several articles have expressed considerable doubts about MFH as an “entity” and have suggested that it represents a common morphologic manifestation of a host of poorly differentiated sarcomas. The researchers in one study concluded that pleomorphic, giant cell and inflammatory variants each represent heterogeneous diagnostic groups, which are hard to defend as cohesive entities, while the myxoid (“myxofibrosarcoma”) and angiomatoid types are distinct, reproducible tumor types.9
The clinical stage of the tumor —which is defined by tumor grade, size, and presence of distant metastases — is the most important prognostic factor. Histologic subtype and method of surgical treatment are also important prognostic factors. The anatomic site and depth of the primary tumor may also be of prognostic importance, but this is controversial.
One published study involved adult patients (median age, 70 years; range, 32 to 94 years). The median tumor size was 8 cm (range, 1 cm to 30 cm), and the thigh was the most common tumor location (n = 31). Median follow-up was 8 years (range, 3 to 16 years). The overall 5-year metastasis-free survival rate was 0.64. In 84 of 100 tumors, a specific line of differentiation was either proved or strongly suggested. The most common diagnoses were myxofibrosarcoma (n = 22) and leiomyosarcoma (n = 20). Overall,
30 tumors could be grouped as some form of myogenic sarcoma. These tumors had a worse prognosis as well as a shorter time to metastasis than nonmyogenic tumors. In addition, pleomorphic MFHs showing myogenic differentiation are significantly more aggressive.10
Two hundred twenty-seven patients with localized disease, having surgery as the principal modality, were reviewed retrospectively to identify clinical outcomes. The mean age of the patients was 54 years. Extremities were the primary tumor site in 157 patients (62.2%).
The overall survival rate was 50%, including 38 patients who died of other causes. Distant metastases were most common to the lung (90%). Local recurrence alone occurred in 37 patients (16%), distant metastases alone in 52 (23%), and distant metastases with local recurrence in 25 (11%).11
The primary tumor size indicated the 5-year survival rate: Tumors smaller than 5 cm had a survival rate of 82%; tumors 5 cm to 10 cm, 68%; and tumors larger than 10 cm, 51%. Intermediate-grade tumors yielded a 5-year survival rate of 80%, and the 5-year survival rate for high-grade tumors was 60%. Survival rates for both grades were affected by size: Tumors of high grade and smaller than 5 cm in diameter had a survival rate of 79%; tumors 5 cm to 10 cm, 63%; and tumors larger than 10 cm, 41%. Grade and size emerge as significant prognostic indicators. These variables will prove helpful in treatment decisions and design of clinical studies.11
The overall survival rate of patients with MFH ranges from 36% to 58% at 5 years; however, patients with retroperitoneal tumors have an overall 5-year survival rate of 15% to 20%. Patients with low-grade, intermediate-grade, and high-grade tumors have 10-year survival rates of 90%, 60%, and 20%, respectively. Patients with tumors smaller than 5 cm at presentation have survival rates of 79% to 82%. Patients with tumors of 5 cm to 10 cm have survival rates of 62% to 68%, compared with those with tumors larger than 10 cm, with survival rates of 41% to 51%.12
Following the diagnosis and staging for metastasis, the patient underwent an above-the knee-amputation and was given a prosthesis. However, as the patient was wheelchair-bound due to age and other health issues, he did not undergo rehabilitation. He remained disease-free and has been followed by his oncologist.