Primary bone metastasis as first manifestation of an unknown primary tumour

Cytomorphological spectrum of metastatic bone tumors: Experience at a tertiary care center

Objectives:

Bone is a frequent site of metastases and typically indicates a short-term prognosis in cancer patients. The majority of skeletal metastases are due to breast and prostate cancer. Bone metastasis is actually much more common than primary bone cancers, especially in adults. Fine-needle aspiration cytology (FNAC) provides reasonably accurate pre-operative diagnosis in vast majority of cases. This study aims to elicit the cytomorphological detail of various metastatic bone tumors.

Material and Methods:

A total of 109 cases of tumors metastatic to bone have been included in this study. The details of the cases were available from the archives of the department of cytology. May Grunwald Giemsa and hematoxylin and eosin stained smears were studied and examined for the cytomorphological spectrum. Cell block and immunohistochemistry tests were done, wherever feasible.

Results:

Among 109 patients, the mean age was 54.52 years. There was male preponderance with 90 males and 19 females. The most common site of metastases was in the vertebra (82 cases), and 76 cases were in the dorsolumbar region. The most common type of tumor metastasizing was adenocarcinoma.

Conclusion:

FNAC is a very useful, economical procedure. There are characteristic cytological features of the metastatic lesions and the basic diagnostic categorization of the malignant tumors is possible on FNAC. Regarding the primary source clinical history, radiological features of the primary tumor, if any, and immunocytochemistry may be needed.

Detection of Ureteral Stump Transitional Cell Carcinoma, Presenting as Bone Metastases from Unknown Primary by 18F-FDG PET/CT: A Case Report with Review of Literature

A case of occult carcinoma of the ureteral stump is reported. A 67-year-old man presented with pain syndrome due to multiple bone metastases from unknown primary origin detected by previous imaging studies as magnetic resonance imaging, whole body contrast-enhanced computed tomography (CT), and technetium-99m methyldiphosphonate bone scan. He had undergone a right nephrectomy for a benign disease previously. He was referred to our department for an 18F-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) to help localize possible primary tumor. Our observations in this case show that the use of 18F-FDG PET/CT successfully and more accurately evaluated the overall tumor burden and led to a rapid decision of an adequate therapeutic approach.

Skeletal Metastases of Unknown Primary: Biological Landscape and Clinical Overview

Skeletal metastases of unknown primary (SMUP) represent a clinical challenge in dealing with patients diagnosed with bone metastases. Management of these patients has improved significantly in the past few years. however, it is fraught with a lack of evidence. While some patients have achieved impressive gains, a more systematic and tailored treatment is required. Nevertheless, in real-life practice, the outlook at the beginning of treatment for SMUP is decidedly somber. An incomplete translational relevance of pathological and clinical data on the mortality and morbidity rate has had unsatisfactory consequences for SMUP patients and their physicians. We examined several approaches to confront the available evidence; three key points emerged. The characterization of the SMUP biological profile is essential to driving clinical decisions by integrating genetic and molecular profiles into a multi-step diagnostic work-up. Nonetheless, a pragmatic investigation plan and therapy of SMUP cannot follow a single template; it must be adapted to different pathophysiological dynamics and coordinated with efforts of a systematic algorithm and high-quality data derived from statistically powered clinical trials. The discussion in this review points out that greater efforts are required to face the unmet needs present in SMUP patients in oncology.

Bone metastasis pattern of cancer patients with bone metastasis but no visceral metastasis

BACKGROUND

Bone metastasis of cancer can be a result from systemic blood spreading or vertebral venous plexus spreading. Systemic blood pathway induced bone metastasis can happen in any bone in the body since the spreading is considered to be random. However, it remains unknown whether there is any pattern of vertebral venous plexus related bone metastasis. In this study, we explored bone metastasis patterns in patients whose primary tumors had been well identified.

METHODS

We included 290 consecutive cancer patients with bone metastases but no visceral metastases, out of 2559 patients whose bone metastases were diagnosed by positron emission tomography/computed tomography, between Jan 2015 and Oct 2017 at the Fudan University Shanghai Cancer Center. We excluded those with visceral metastasis to ensure that our study focused on metastasis through the vertebral venous plexus. And we analyzed the distribution and pattern of skeletal metastases.

RESULTS

Of the 290 patients, 28 had head and neck tumors, 178 had thorax tumors, 49 had abdominal tumors and 35 had pelvic tumors; 102 (35%) had only one bone containing a metastasis and 188 (65%) had multiple bones containing metastases. Overall, metastases to the thoracic skeleton were more common in patients with thorax tumors than in other patients (81% vs. 67%, P = 0.007); metastases to the cervical spine or thoracic bones were more common in patients with primary tumors above the diaphragm than those below the diaphragm (82% vs. 66%, P = 0.002). Among those with only one bone containing a metastasis (n = 102), patients with head and neck tumors had a higher incidence of cervical spine metastasis than other patients (25% vs. 2%, P = 0.03), those with thorax tumors had a higher incidence of thoracic bone metastasis than other patients (56% vs. 35%, P = 0.035), and those with pelvic tumors had a higher incidence of pelvis bone metastasis than other patients (78% vs. 27%, P = 0.000054).

CONCLUSIONS

In patients with only one bone containing a metastasis but no visceral metastasis, bones near the primary were more likely to be first metastasized. This may be a valuable clue to primary tumor sites in patients with cancers of unknown primaries.