Abstract
Skeletal sarcoma metastasis is relatively rare; moreover, for this type of metastasis, the temporal bone is also a rare location. The temporal bone appears to be affected by metastatic tumors in discrete histopathologic patterns, with characteristic clinical presentations. In this study, we analyzed the records of 6 patients with skeletal sarcoma metastasis to the temporal bone, with an emphasis on histopathologic sections of human temporal bones. The most common site of sarcoma metastasis in the temporal bone was petrous apex in our series. Physicians should keep in mind that a sarcoma patient may manifest with ear findings due to temporal bone metastasis.
1
Introduction
Skeletal sarcoma metastasis is relatively rare; moreover, for this type of metastasis, the temporal bone is also a rare location. The temporal bone appears to be affected by metastatic tumors in discrete histopathologic patterns, with characteristic clinical presentations. The incidence of skeletal sarcoma metastasis to the temporal bone seems to be increasing, given the generally increasing incidence of cancer as well as the increase in life expectancy.
More effective methods of radiochemotherapy have interrupted the course of sarcoma and allowed more time for metastasis . The mechanism of temporal bone metastasis can be explained by 5 distinct patterns: (1) hematogenous spread of carcinoma, leading to seeding of the marrow spaces of the petrous bone; (2) access by tumor cells to the cerebrospinal fluid (CSF) and dissemination through the subarachnoid space into the internal auditory canal (IAC); (3) direct extension; (4) leptomeningeal extension from an intracranial primary tumor; and (5) leukemic or lymphomatous infiltration .
The 6 most common primary malignancies that metastasize to the temporal bone are breast, lung, kidney, stomach, bronchus, and prostate , and the 5 most common sites of metastasis within the temporal bone are the petrous apex, IAC, mastoid cavity, external auditory canal, and middle ear . Because skeletal sarcoma metastasis to the temporal bone is very rare, only a few case reports have been published in the literature, rather than a large case series. Those case reports involved synovial sarcoma, angiosarcoma, histiocytic sarcoma, reticular cell sarcoma, liposarcoma, rhabdomyosarcoma, osteosarcoma, and hemangiopericytoma .
Occasionally, the temporal bone is the site of origin of a sarcoma. Several petrosal sarcomas have been found in children and in young adults. Such sarcomas infiltrate rapidly, produce multiple cranial nerve palsies, and usually result in death from intracranial extension.
In this study, we analyzed the records of 6 patients with skeletal sarcoma metastasis to the temporal bone, with an emphasis on histopathologic sections of human temporal bones (HTBs).
2
Materials and methods
This study was approved by the University of Minnesota institutional review board (0206M26181).
Using the University of Minnesota temporal bone collection, we analyzed the histopathologic sections of 11 HTBs from 6 patients with different types of skeletal sarcoma metastasis to the temporal bone. All of the HTB specimens were prepared per the standard technique of light microscopy, including fixation, decalcification, and serial 20-μm sectioning in the horizontal plane; they were then stained with hematoxylin and eosin (H&E). We evaluated each HTB under light microscopy for the presence of tumor cells and noted the site of involvement.
We reviewed the corresponding clinical records and autopsy reports. For each of the 6 patients, we retrieved demographic data and noted the clinical course, otologic and vestibular manifestations, site of primary malignant tumor, and histologic features. The histopathologic diagnoses of tumors metastasized to the ear included Ewing sarcoma (2 patients), rhabdomyosarcoma (1 patient), angiosarcoma (1 patient), liposarcoma (1 patient), and reticular cell sarcoma (1 patient). Of the 6 patients, 4 had bilateral temporal bone metastasis; 2, unilateral. For the patient with reticular cell sarcoma metastasis, the opposite ear was not available for evaluation. Patient characteristics and diagnoses are summarized in Table 1 .
| Histopathologic diagnosis | Age | Sex | Site of the metastasis | Symptoms of ear | |
|---|---|---|---|---|---|
| 1 | Rhabdomyosarcoma | 45 | F | Bilateral internal auditory canal | Bilateral hearing loss Left facial palsy |
| 2 | Ewing sarcoma | 18 | M | Left petrous apex Right mastoid cavity and right petrous apex | Bilateral decrease of hearing |
| 3 | Reticular cell sarcoma a | 68 | F | Right mastoid cavity | A nodule behind the right ear |
| 4 | Liposarcoma | 74 | M | Left petrous apex | – |
| 5 | Ewing sarcoma | 23 | F | Bilateral petrous apex | Bilateral decrease of hearing and tinnitus |
| 6 | Angiosarcoma | 31 | F | Bilateral petrous apex | – |
2.1
Case 1 (rhabdomyosarcoma)
A 45-year-old female patient who described a mass on her left tibia underwent a local excision; histopathologic examination revealed alveolar rhabdomyosarcoma. She then underwent a local block excision with skin grafting of the left tibial area.
After 11 months, she was admitted again, because of lower back pain. An open biopsy of the primary lesion detected local recurrence; a myelogram showed complete obstruction due to a large epidural mass on the anterior space of the body of lumbar vertebra 5 (L5). She underwent a mid-thigh amputation of the left leg, followed by radiation therapy (40 Gy) to the lumbar spine.
Then, 2 months after her most recent discharge, she was readmitted with paraplegia. A laminectomy detected metastatic intramedullary rhabdomyosarcoma. Three days after that operation, she became lethargic, with bilateral profound hearing loss, hoarseness, dysphagia, and left facial palsy. Neurologic examination including hearing test revealed complete palsy of the left VII, bilateral VIII, right IX, and right X cranial nerves, as well as stiffness on flexion of the neck.
Despite treatment with steroid and antibiotics, she experienced respiratory arrest and was pronounced dead 7 days after the laminectomy. At autopsy, intracranial examination revealed multiple brain metastases and tumor involvement of meninges at the basal region, especially at the basal cisterns.
2.1.1
Histopathologic findings, left temporal bone
The external auditory canal (EAC) and middle ear were normal, but tumor cells were detected in the labyrinthine segment of the fallopian canal. Serous labyrinthitis was observed in the membranous labyrinth. The organ of Corti was damaged in all sections of cochlea; hair cells were not seen. A few tumor cells were detected in the scala tympani. The stria vascularis was slightly atrophic. The VII and VIII cranial nerves were destroyed by tumor cells; the number of Scarpa’s ganglion cells was decreased in the IAC ( Fig. 1 ). The maculae of the utricle and saccule were infiltrated by white blood cells and slightly damaged by labyrinthitis. The cristae of the superior semicircular canal (SSC) and lateral semicircular canal (LSC) appeared normal; however, the crista of the posterior semicircular canal (PSC) was infiltrated by white blood cells and partially damaged by labyrinthitis.
2.1.2
Histopathologic findings, right temporal bone
The EAC was normal. The middle ear was also normal, but the tympanic membrane was retracted and attached to the long process of the incus and the head of stapes. Tumor invasion of the labyrinthine segment of the fallopian canal was observed. Purulent labyrinthitis was seen in the perilymphatic spaces of the membranous labyrinth. The organ of Corti was seriously damaged; hair cells had completely disappeared. In the scala tympani, scala vestibuli, and ductus cochlearis, many deformed erythrocytes were present. The stria vascularis was atrophied. The maculae of the utricle and saccule, and the cristae of all of the semicircular canals were infiltrated by white blood cells and showed minor damage caused by labyrinthitis. The IAC was filled with tumor cells, and the VII and VIII cranial nerves in the IAC were destroyed.
2.2
Case 2 (Ewing sarcoma)
An 18-year-old male patient was admitted to the hospital with left thigh pain. An x-ray revealed radiolucent areas of upper left femur; a persistently elevated erythrocyte sedimentation rate (ESR) was noted. A biopsy of the left femur revealed Ewing sarcoma. He underwent radiochemotherapy.
After his discharge he noted several small masses in various locations, including the mid upper arm posteriorly on the left, the right inguinal region, and the plantar surface of the right foot. Several biopsies of those locations, including the right inguinal region and the left thigh, confirmed the diagnosis of Ewing sarcoma with distant metastasis. He also had a bilateral decrease in his hearing, without tinnitus, as well as progressive development of severe back pain and upper thoracic pain accentuated by coughing.
Although he underwent radiochemotherapy, he died 9 months after the diagnosis. Autopsy revealed widespread metastasis of Ewing sarcoma to the heart, lungs, ribs, and bone marrow.
2.2.1
Histopathologic findings, left temporal bone
The EAC, tympanic membrane, and middle ear were within normal limits; the ossicular chain was intact. The facial nerve was normal. The mastoid air cells were well pneumatized, with marked hyperplasia of the mucoperiosteum. The organ of Corti and the spiral ligament were not evaluated, because of some processing artifacts. The SSC, LSC, PSC, utricle and saccule appeared to be normal. The IAC, including the facial nerve in the canal, was unremarkable. Metastatic infiltration of the tumor was noted in the bone marrow of the petrous apex.
2.2.2
Histopathologic findings, right temporal bone
The EAC, tympanic membrane, and middle ear were within normal limits; the ossicular chain was intact. The facial nerve was normal. The mastoid air cells were well pneumatized, with hyperplasia of the mucoperiosteum. Metastatic foci of tumor cells and cholesterol granuloma were seen in mastoid air cells, with slight serous effusion. The SSC, LSC, PSC, utricle and saccule were within normal limits. The organ of Corti and the spiral ligament were not evaluated, because of some processing artifacts. The IAC, including the facial and cochlear nerves, appeared to be normal. The bone marrow of the petrous apex was infiltrated with metastatic malignant cells.
2.3
Case 3 (reticular cell sarcoma)
A 68-year-old female patient came to the hospital with a histiocytic lymphoma (reticular cell sarcoma) involving the posterior skull. After it was surgically removed, she did quite well for a while.
However, she returned with a nodule behind the right ear and a mass in the left lower lobe of the lung. Hearing test results revealed a hearing loss on left ear and right ear was normal. A biopsy of the subcutaneous mass was positive for histiocytic lymphoma (reticular cell sarcoma). She was treated with chemotherapy; the lung nodule subsequently disappeared.
Six years later, she was readmitted with a high fever and a large pelvic mass. Because of metabolic acidosis, she began dialysis before her death. Autopsy revealed tumor invasion in the bone marrow, spleen, and entire lymphatic system.
2.3.1
Histopathologic findings, left temporal bone
The EAC, tympanic membrane, and middle ear were within normal limits; the ossicular chain was intact. The facial nerve was normal. Subepithelial hemorrhage in the middle ear was noted. The IAC was within normal limits. The inner ear structures showed damage at removal.
2.3.2
Histopathologic findings, right temporal bone
The EAC, tympanic membrane, and middle ear were within normal limits; the ossicular chain was intact. Subepithelial hemorrhage in the middle ear was noted. Reticular cell sarcoma metastasis was seen in the mastoid cavity ( Fig. 2 ). The IAC was normal. The inner ear structures were not adequate for evaluation, because of severe damage at removal.
2.4
Case 4 (liposarcoma)
A 74-year-old male patient was seen in the hospital for a recurrent liposarcoma of the left upper arm, 2 years after undergoing a radical operation. He underwent chemotherapy, but 1 year later, had an axillary recurrence of the tumor and was treated with radiation this time. Because of tumor progression, he underwent a forequarter amputation. During the course of treatment, he developed swelling of the lower extremities, dysuria, and pneumonia. Two days before his death, he developed bright-red rectal bleeding and hypotension; he became progressively obtunded (despite initial response of his hypotension).
He died with anuria and shock. Autopsy revealed a lymphoproliferative syndrome, with malignant cells in lymph nodes and in bone marrow, in addition to an incidental pheochromocytoma. Neuropathologic examination also revealed mild, fresh, and patchy subarachnoid hemorrhage.
2.4.1
Histopathologic findings, left temporal bone
The EAC and tympanic membrane were within normal limits. The middle ear mucosa was thickened. The facial nerve was normal. The LSC, SSC, PSC, utricle and saccule were within normal limits. The IAC, including the vestibulocochlear and facial nerves, was within normal limits, except for the presence of some erythrocytes. Spiral ganglion cells and the organ of Corti were normal, with a limited serous labyrinthitis in the scala vestibuli. The carotid artery was noted to be dehiscent. Metastatic liposarcoma involvement of the bone marrow was seen in the petrous apex.
The right temporal bone was not available for our study.
2.5
Case 5 (Ewing sarcoma)
A 23-year-old female patient (with a limited medical record) had massive involvement of Ewing sarcoma on the right pleura. She underwent chemotherapy, which included cisplatin. She experienced tinnitus and gradual hearing loss during the course of the disease.
2.5.1
Histopathologic findings, left temporal bone
The EAC, tympanic membrane, and middle ear were within normal limits except for hemorrhage and facial nerve dehiscence. The cochlea was partially damaged during the removal process; however decreased hair cell density was seen. The SSC, LSC, PSC, utricle and saccule were within normal limits. The IAC, including the vestibulocochlear and facial nerves, was within normal limits. Metastatic Ewing sarcoma involvement of the bone marrow in the petrous apex, with necrosis, was noted.
2.5.2
Histopathologic findings, right temporal bone
The EAC and tympanic membrane were within normal limits and ossicular chain was intact. The middle ear mucosa was thickened within hemorrhage. The facial nerve was normal. Cochlear hair cell density was decreased. The SSC, LSC, PSC, utricle and saccule were normal. The IAC, including the vestibulocochlear and facial nerves, was within normal limits. Metastatic Ewing sarcoma involvement of the bone marrow in the petrous apex, with necrosis, was noted.
2.6
Case 6 (angiosarcoma)
A 31-year-old female patient had abdominal pain and a back lesion. She underwent resection; the diagnosis was angiosarcoma. Because of persistent abdominal pain, she then underwent an exploratory laparotomy, and subsequently a total abdominal hysterectomy, a bilateral salpingo-oophorectomy, and a mass resection. The tumor was apparently refractory to chemotherapy.
She was discharged to a hospice, where she died of multi-organ system failure caused by metastatic and aggressive angiosarcoma. Autopsy revealed a substantial gross amount of abdominal tumor: a metastatic high-grade angiosarcoma involving the soft tissues of the pelvis, the serosa of the large and small intestine, all identifiable abdominal lymph nodes, the spleen, and the liver, in addition to metastatic vertebral bone marrow involvement. Also noted were bilateral acute bronchopneumonia, bilateral serosanguinous pleural effusion, cholelithiasis (with a single large bilirubin gallstone), hepatic necrosis, left nephrocalcinosis, and serosanguinous abdominal ascites.
2.6.1
Histopathologic findings, left temporal bone
The EAC, tympanic membrane, and middle ear were within normal limits and ossicular chain was intact. The facial canal was evaluated as normal. The cochlea was within normal limits, with some serous precipitation in the scala media. Spiral ganglion cells were normal. The SSC, LSC, PSC, utricle and saccule were within normal limits. The IAC, including the vestibulocochlear and facial nerves, was unremarkable. The bone marrow of the petrous apex was infiltrated with metastatic malignant cells.
2.6.2
Histopathologic findings, right temporal bone
The EAC, tympanic membrane, and middle ear were within normal limits and ossicular chain was intact. The facial canal was evaluated as normal. The cochlea was within normal limits, except for mild serous labyrinthitis in the scala media. Spiral ganglion cells were within normal limits. The SSC, LSC, PSC, utricle and saccule were within normal limits. The IAC, including the vestibulocochlear and facial nerves, was unremarkable. The bone marrow of the petrous apex was infiltrated with metastatic malignant cells ( Fig. 3 ).
