Metastatic Melanoma from Unknown Primary Presenting as Dorsal Midbrain Syndrome

Report on a case of liver-originating malignant melanoma of unknown primary

Malignant melanoma (MM) frequently occurs in the skin or mucosa, whereas malignant melanoma of unknown primary (MUP) is diagnosed in patients with lymph nodes or visceral organs as the site of origin, where it is challenging to detect the primary lesion by comprehensive examination. MUP is possibly related to the spontaneous regression of the primary lesion. In addition, primary hepatic melanoma (PHM) usually refers to the primary MM occurring in the liver, with no typical primary lesions and no manifestations of tumor metastasis. A 61-year-old male patient with liver as the site of origin was diagnosed with MM by Melan-A, HMB-45, and S-100 immunohistochemistry staining of liver biopsy tissue. Based on a comprehensive examination, no basis was found for melanoma in sites such as the skin, mucosa, five sense organs, brain, digestive tract, respiratory tract, or genitalia, and the patient was subsequently diagnosed with MUP. MMs require a comprehensive inspection, beginning with the liver, to search for the primary lesion; if the primary lesion is not found, the possibility of PHM or MUP should be considered.

Approach to Patients with Malignant Melanoma of Unknown Primary Origin

Objectives:

Although malignant melanoma accounts for 3% of skin cancers, it is responsible for 75% of deaths associated with skin cancer. In our study, all melanoma cases diagnosed and treated at our clinic were retrospectively reviewed, and the cases of unknown primary origin among them were examined in detail in terms of diagnosis and treatment.

Methods:

The patients with malignant melanoma treated at the inpatient services of our clinic between January 1991 and April 2017 were retrospectively screened in the records. These patients were evaluated for age, sex, tumor type, Breslow depth, metastasis, and treatment. Among these patients, four cases of unknown primary origin were examined in detail.

Results:

During January 1991 and April 2017, 173 patients received inpatient care for malignant melanoma at our clinic. As regards to the melanoma subtypes, nodular type in 45 patients, acral lentiginous type in 43 patients, superficial spreading type in 63 patients, lentigo maligna melanoma in 15 patients, subungual type in 7 patients, and either unidentified melanoma or other subtypes in 10 patients were identified.

Conclusion:

The ideal treatment of a patient with melanoma is multidisciplinary, with plastic surgery having a central role.

Toxicity of Radiosurgery for Brainstem Metastases

BACKGROUND

Although stereotactic radiosurgery (SRS) is an effective modality in the treatment of brainstem metastases (BSM), radiation-induced toxicity remains a critical concern. To better understand how severe or life-threatening toxicity is affected by the location of lesions treated in the brainstem, a review of all available studies reporting SRS treatment for BSM was performed.

METHODS

Twenty-nine retrospective studies investigating SRS for BSM were reviewed.

RESULTS

The rates of grade 3 or greater toxicity, based on the Common Terminology Criteria for Adverse Events, varied from 0 to 9.5% (mean 3.4 ± 2.9%). Overall, the median time to toxicity after SRS was 3 months, with 90% of toxicities occurring before 9 months. A total of 1243 cases had toxicity and location data available. Toxicity rates for lesions located in the medulla were 0.8% (1/131), compared with midbrain and pons, respectively, 2.8% (8/288) and 3.0% (24/811).

CONCLUSIONS

Current data suggest that brainstem substructure location does not predict for toxicity and lesion volume within this cohort with median tumor volumes 0.04-2.8 cc does not predict for toxicity.

Parinaud syndrome: Any clinicoradiological correlation?

INTRODUCTION

The significance of MRI findings of patients with Parinaud syndrome (PS) with respect to clinical characteristics is poorly defined. Over the past decades, all patients with PS undergo magnetic resonance imaging which allows a better identification of the lesion localization. We compared the neuro-ophthalmological findings of patients with PS caused by intrinsic (intra-axial) vs extrinsic (pineal gland tumor) brainstem lesions.

METHODS

Medical records of patients with PS evaluated between 2000 and 2016 were retrospectively reviewed.

RESULTS

Twenty-six patients with PS were included. Eight patients had pineal gland tumors and hydrocephalus. Two patients had hydrocephalus due to aqueduct stenosis and fourth ventricle tumor. Sixteen patients suffered from an intrinsic brainstem lesion and seven associated with hydrocephalus. The neuro-ophthalmological findings did not differ between patients with extrinsic and intrinsic brainstem lesions. No correlation was found between the grade of hydrocephalus and number of clinical findings except for more findings in low-grade hydrocephalus in intrinsic (40%) vs extrinsic (0%) lesions (P=.003). Patients with moderate brainstem lesions and hydrocephalus had more clinical findings (65%) than patients with the same grade of brainstem involvement without hydrocephalus (29%) (P=.03). The resolution rate of ophthalmological findings was comparable in all groups of patients.

CONCLUSIONS

Our results did not show differences in neuro-ophthalmological findings between intra- and extra-axial lesions causing PS. However, the presence of hydrocephalus was an important factor influencing clinical findings. The prognosis of PS was less favorable than generally reported.