Metastasis to the forearm skeletal muscle from an adenocarcinoma of the colon: report of a case

Ossifying skeletal muscle metastasis as an initial manifestation of colorectal adenocarcinoma

Skeletal muscle metastases from colorectal cancer (CRC) are very rare. They have usually been described in patients with known CRC and as a well-defined mass. In this case report, we present a unique case of diffuse and ossifying skeletal muscle metastasis as the first manifestation of CRC. A 36-year-old man presented with progressive left thigh swelling and left hip pain of 6 months duration. He denied any gastrointestinal complaints. CT and MRI of the thigh showed diffuse muscular swelling, signal abnormalities with linear calcifications involving the muscles of the posterior and medial compartments of the left thigh and both gluteal regions. Histology confirmed the metastatic nature of a colorectal adenocarcinoma. The patient was treated with chemotherapy and showed a good evolution after 6 months of follow-up.

Skeletal muscle dissemination in a dog with T-cell lymphoma

A 5-year-old spayed female American Staffordshire was referred for weakness, reluctance to move and distension of the abdomen. Three weeks before, the dog underwent surgery for excision of a nodular mass suspected to be a non-epitheliotropic cutaneous T-cell lymphoma (NE-CTCL). Computed tomography revealed heterogeneous enhancing mesenteric masses and nodular lesions of soft tissue density, and infiltration of the abdominal muscular wall. Moreover, a pattern of diffuse muscle nodules in the skeletal muscles was visible, with lesions showing homogenous, heterogeneous or ring enhancement. Necrosis was histologically observed and these lesions were infiltrated by CD3-positive and CD20-, CD79a- and Iba1-negative neoplastic lymphocytes. On the basis of the immunopathological features metastatic NE-CTCL was suspected. Skeletal muscle metastasis has been rarely reported in small animals and this case report further confirms that this possibility should be considered in dogs with lymphoma.

Skeletal muscle metastasis from colorectal adenocarcinoma: A literature review

BACKGROUND

Colorectal adenocarcinoma is the third most common cancer worldwide. It accounts for almost 10% of all cancer-related deaths. Skeletal muscle is a very unusual site for metastasis from colorectal cancers and is associated with a poor prognosis and high mortality.

AIM

To review the literature for cases of skeletal muscle metastasis (SMM) from colorectal adenocarcinoma.

METHODS

A systematic literature search using a validated search strategy was carried out to identify the incidence of SMM associated with colorectal adenocarcinoma. The studies identified were tabulated in a PRISMA, and data was extracted in a tabulated form.

RESULTS

Twenty-nine studies were included in this literature review. SMM was most commonly detected in the thigh muscles. Most of the tumours had originated from the rectum or the right colon. The histopathology of the primary tumour was generally advanced. The mean time interval between the primary tumour and onset of SMM was 22 mo. In 3 cases, asymptomatic SMM had been picked up by advanced imaging systems, like fluorodeoxyglucose-positron emission tomography scan.

CONCLUSION

SMM from colorectal adenocarcinomas is a rare complication. However, it is possible that the low incidence could be due to under-reporting. Early use of advanced imaging techniques and a high index of clinical suspicion might increase the reporting of SMM from colorectal adenocarcinoma.

Brachialis muscle metastasis: An unusual, presenting site of metastatic adenocarcinoma of the colon

Skeletal muscle metastasis from gastrointestinal system tumours is extremely rare. We report an unusual presentation of skeletal muscle metastasis in the brachialis muscle as a presenting feature of a previously undiagnosed colonic adenocarcinoma in a 66-year-old male. He presented to us with a painful, flexion deformity of his elbow and suspected to have a biceps brachii rupture. We review the clinico-radiological findings and the relevant literature. This case-report highlights the importance of a thorough clinical evaluation especially in presence of red flag signs, early multi-disciplinary team (MDT) discussion and biopsy to formulate a plan of management.

Skeletal muscle metastasis with bone metaplasia from colon cancer: A case report and review of the literature

BACKGROUND

Colon cancer is a common malignant disease of the gastrointestinal tract and usually occurs at the junction of the rectum and sigmoid colon. Lymphatic and hematogenous metastases occur frequently in colon cancer and the most common metastatic sites include the liver, lung, peritoneum, bone, and lymph nodes. As a manifestation of advanced tumor spread and metastasis, soft tissue metastasis, especially skeletal muscle metastasis with bone metaplasia caused by colon cancer, is rare, accounting for less than 1% of metastases.

CASE SUMMARY

A 43-year-old male patient developed skeletal muscle metastasis with bone metaplasia of the right proximal thigh 5 mo after colon cancer was diagnosed. The patient was admitted to the hospital because of pain caused by a local mass on his right thigh. Positron emission tomography-computed tomography showed many enlarged lymph nodes around the abdominal aorta but no signs of lung or liver metastases. Color ultrasound revealed a mass located in the skeletal muscle and the results of histological biopsy revealed a poorly differentiated adenocarcinoma suspected to be distant metastases from colon cancer. Immunohistochemistry showed small woven bone components that were considered to be ossified.

CONCLUSION

This case reminds us that for patients with advanced colorectal tumors, we should be alert to the possibility of unconventional metastasis.

Solitary Cystic Psoas Muscle Metastasis From Rectosigmoid Adenocarcinoma

The most common subtype of colon cancer is colorectal adenocarcinoma. Compared with other subtypes, such as signet-ring and mucinous, colorectal adenocarcinoma has been found to have lower rates of metastasis. Approximately 20% of colorectal cancer cases present with metastatic disease on initial evaluation. The most common locations for metastasis are the liver, lung, peritoneum, bone, and extra-regional lymph nodes. Metastatic disease to the skeletal muscle, however, is considerably rare. We present a clinical case of a 52-year-old female found to have a cystic iliopsoas muscle metastasis from rectosigmoid adenocarcinoma, initially classified as an infected fluid collection.

Diagnostic value of spectral reconstructions in detecting incidental skeletal muscle metastases in CT staging examinations

Background

To investigate if iodine density overlay maps (IDO) and virtual monoenergetic images at 40 keV (VMI_40keV) acquired from spectral detector computed tomography (SDCT) can improve detection of incidental skeletal muscle metastases in whole-body CT staging examinations compared to conventional images.

Methods

In total, 40 consecutive cancer patients who underwent clinically-indicated, contrast-enhanced, oncologic staging SDCT were included at this retrospective study: 16 patients with n = 108 skeletal muscle metastases confirmed by prior or follow-up CT, ¹⁸F-FDG-PET, MRI or histopathology, and a control group of 24 patients without metastases. Four independent readers performed blinded, randomized visual detection of skeletal muscle metastases in conventional images, IDO and VMI_40keV, indicating diagnostic certainty for each lesion on a 5-point Likert scale. Quantitatively, ROI-based measurements of attenuation (HU) in conventional images and VMI_40keV and iodine concentration in IDO were conducted. CNR was calculated and receiver operating characteristics (ROC) analysis of quantitative parameters was performed.

Results

Regarding subjective assessment, IDO (63.2 (58.5–67.8) %) and VMI_40keV (54.4 (49.6–59.2) %) showed an increased sensitivity for skeletal muscle metastases compared to conventional images (39.8 (35.2–44.6) %). Specificity was comparable in VMI_40keV (69.8 (63.2–75.8) %) and conventional images (69.2 (60.6–76.9) %), while in IDO, it was moderately increased to 74.2 (65.3–78.4) %. Quantitative image analysis revealed that CNR of skeletal muscle metastases to circumjacent muscle was more than doubled in VMI_40keV (25.8 ± 11.1) compared to conventional images (10.0 ± 5.3, p ≤ 0.001). Iodine concentration obtained from IDO and HU acquired from VMI_40kev (AUC = 0.98 each) were superior to HU attenuation in conventional images (AUC = 0.94) regarding differentiation between healthy and metastatic muscular tissue (p ≤ 0.05).

Conclusions

IDO and VMI_40keV provided by SDCT improve diagnostic accuracy in the assessment of incidental skeletal muscle metastases compared to conventional CT.

Solitary Skeletal Muscle Metastasis as First Site of Recurrence of Cervical Cancer: A Case Report

Cervical cancer is the fourth most common cancer in women worldwide, with a large majority of prevalence (85%) in developing countries. As of 2012, it accounts for 7.5% of all female cancer deaths. Despite its high prevalence, skeletal muscle metastasis from cervical cancer is extremely uncommon. In our extensive literature search, we were able to find only 8 cases where skeletal muscle metastasis was the only site of recurrence. We report a case of a 52-year-old African-American woman with a past medical history of cervical cancer (stage IIIB) who presented with pain and swelling in her left upper arm over the preceding 2 months. MRI of the left upper arm showed a solid well-circumscribed mass measuring 7.0 × 2.8 × 2.5 cm, deep to the biceps. Biopsy of the mass revealed a metastatic squamous cell carcinoma that was p16-positive. PET scan showed that the lesion was the sole site of metastasis. She received local radiation with concurrent chemotherapy. Follow-up MRI 6 months after the completion of therapy showed resolution of the mass. She has remained disease-free for the last 24 months as evidenced by a PET/CT scan in May 2016. In this case report, we discuss the role of imaging and pathology in the diagnosis of a solitary metastatic lesion. This case also emphasizes the importance of a close follow-up which aids in early intervention, increasing overall survival.

Tumors Involving Skin, Soft Tissue and Skeletal Muscle: Benign, Primary Malignant or Metastatic?

BACKGROUND

Metastatic cancer with invasion of skin, soft tissue and skeletal muscle is not common. Examples presenting as soft tissue masses could sometimes lead to misdiagnosis with delayed or inappropriate management. The purpose of current study was to investigate clinical characteristics in the involvement of metastatic cancer.

MATERIALS AND METHODS

A total of 1,097 patients complaining of skin or soft tissue masses and/or lesions were retrospectively reviewed from January 2012 to June 2013. Tumors involving skin, soft tissue and skeletal muscle of head and neck, chest wall, abdominal wall, pelvic region, back, upper and lower extremities were included in the study.

RESULTS

Fifty-seven (5.2%) patients were recognized as having malignancies on histopathological examination. The most common involvement of malignancy was basal cell carcinoma, followed by cutaneous squamous cell carcinoma, sarcoma and melanoma. The most common anatomical location in skin and soft tissue malignancies was head and neck (52.6% of the malignancies). Four (0.36%) of the malignant group were identified as metastatic cancer with the primary cancer source from lung, liver and tonsil and the most common site was upper extremities. One of them unexpectedly expired during the operation of metastatic tumor excision at the scalp.

CONCLUSIONS

Discrimination between benign and malignant soft tissue tumors is crucial. Performance of imaging study could assist in the differential diagnosis and the pre-operative risk evaluation of metastatic tumors involving skin, soft tissue and skeletal muscle.

The value of 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography in the detection and characterization of soft tissue metastasis

Metastatic tumours presenting as soft tissue metastasis (STM) are relatively rare. STM represents metastasis to the muscle and subcutaneous tissues. The majority of the currently available clinical or radiological data on STM consist of isolated case reports or reviews. The aim of this study was to report the manifestations, origin and distribution of STM detected by ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) and to assess the value of ¹⁸F-FDG PET/CT in the characterisation of STM. We reviewed 17 cases of patients with STM who underwent ¹⁸F-FDG PET/CT scanning. The imaging and clinical data of these patients were retrospectively analysed. This method is very sensitive in the detection of STM and provides ample information for clinical tumour staging. PET is more sensitive compared to CT in detecting lesions in muscle, before the density and morphology of the soft tissues are altered, providing a clear view within the soft tissue. Due to the limitations in resolution, PET is less sensitive compared to CT in detecting lesions in the subcutaneous tissues. The aim of this study was to improve our knowledge of ¹⁸F-FDG PET/CT findings in the diagnosis of STM and determine its value in the staging of malignant tumours.

Muscle metastases: comparison of features in different primary tumours

Background

Muscle metastases (MM) from solid tumours are rare. The aim of this study was to describe radiological features of MM, and to compare their patterns in different malignancies.

Methods

A retrospective search in the statistical database of our institution revealed 61 cases of MM. Additionally, a retrospective search in Pubmed database was performed. Together with our cases the present analysis comprises 461 patients (682 MM).

Results

MM derived from the following malignancies: lung cancer (25.1%), gastrointestinal tumours (21.0%), and urological tumours (13.2%). Other neoplasias with MM were rare. MM were localised most frequently in the thigh muscles, the extraocular musculature, and the gluteal and paravertebral muscles. The localisation of MM was different in several primary malignancies.

On computed tomography (CT), five different patterns of MM occurred: masses with homogeneous contrast enhancement (type I, 46.5%), abscess-like lesions (type II, 27.7%), diffuse infiltration with muscle swelling (type III, 18.1%), intramuscular calcifications (type IV, 6.5%), or MM presented as intramuscular bleeding (type V, 1.2%). MM from several primary tumours manifested with different CT patterns.

On MRI, most MM were hyperintense in comparison to unaffected musculature in T2 weighted images and hypo- to isointense on T1 weighted images with a heterogeneous enhancement. There were no differences in MRI features of MM in different primary tumours. On ultrasound, most MM were hypoechoic. On positron emission tomography, MM presented as focally abnormal intramuscular uptake.

Conclusion

MM present with a broad spectrum of radiological features. Different CT imaging findings of MM were observed in different primary tumours. The localisation of MM also varies with different primary malignancies.

Magnetic resonance imaging of intramuscular metastases

OBJECTIVE

The aim of the present study was to analyse magnetic resonance findings of intramuscular metastases (IM) in a relatively large series.

MATERIALS AND METHODS

From January 2000 to January 2010, 28 patients (207 metastases) were retrospectively identified in the radiological database of the Martin-Luther-University. Several different scanning protocols were used depending on the localisation of IM. In 12 patients diffusion-weighted (DW) images were obtained with a multi-shot SE-EPI sequence. Apparent diffusion coefficient (ADC) maps were also calculated. Furthermore, fusion images were manually generated between the DW and half-Fourier acquisition single-shot turbo spin echo (HASTE) images.

RESULTS

On T2-weighted images, 97% of the recognised IM were hyperintense in comparison to unaffected musculature, and 3% were mixed iso- to hyperintense. On T1-weighted images most IM (91%) were homogeneously isointense in comparison to muscle tissue, whereas 4% were hypointense, and 5% lightly hyperintense. ADC maps were calculated for 91 metastases ranging from 0.99 to 4.00 mm(2)s(-1) (mean value 1.99 ± 0.66). ADC values of low (<1.5) signal intensity (SI) were identified in 26%, moderate SI (from 1.5 to 3.0) in 68%, and high SI (>3.0) in 6%. Of the IM that were investigated with contrast medium, 88.5% showed marked enhancement. It was homogeneous in 88% and heterogenous in 6%. Rim enhancement with central low attenuation was seen in 6%. There was no difference in enhancement characteristics with respect to ADC values or fusion patterns. Peritumoral enhancement was identified in 2.4%.

CONCLUSION

Magnetic resonance features of muscle metastases are relatively typical and consist of round or oval intramuscular masses with well-defined margins, marked enhancement, low or moderate ADC values, and moderate to high signal intensity on fusion images.

Skeletal muscle metastases: primary tumours, prevalence, and radiological features

BACKGROUND

Although skeletal muscles comprise nearly 50% of the total human body mass and are well vascularised, metastases in the musculature are rare. The reported prevalence of skeletal muscle metastases from post-mortem studies of patients with cancer is inconstant and ranges from 0.03 to 17.5%.

MATERIALS AND METHODS

Of 5,170 patients with metastasised cancer examined and treated at our institution during the period from January 2000 to December 2007, 61 patients with muscle metastases (80 lesions) were identified on computed tomography (CT). Genital tumours (24.6%) were the most frequent malignancies metastasising into the skeletal musculature, followed by gastrointestinal tumours (21.3%), urological tumours (16.4%), and malignant melanoma (13.1%). Other primary malignancies were rarer, including bronchial carcinoma (8.2%), thyroid gland carcinoma (4.9%), and breast carcinoma (3.3%). In 8.2%, carcinoma of unknown primary was diagnosed.

RESULTS

Skeletal muscle metastases (SMM) were located in the iliopsoas muscle (27.5%), paravertebral muscles (25%), gluteal muscles (16.3%), lower extremity muscles (12.5%), abdominal wall muscles (10%), thoracic wall muscles (5%), and upper extremity muscles (3.8%). Most (76.3%) of the 80 SMM were diagnosed incidentally during routine staging CT examinations, while 23.7% were symptomatic.

CONCLUSION

Radiologically, SMM presented with five different types of lesions: focal intramuscular masses (type I, 52.5% of SMM), abscess-like intramuscular lesions (type II, 32.5%), diffuse metastatic muscle infiltration (type III, 8.8%), multifocal intramuscular calcification (type IV, 3.7%) and intramuscular bleeding (type V, 2.5%).

Unusual sites of colorectal cancer metastasis

We present 2 separate cases of adenocarcinoma of the colon with metastasis to the chin and the bladder, both of which are unusual sites of colorectal cancer metastasis. Patient 1 is a 77-year-old man who was diagnosed with adenocarcinoma of the colon, American Joint Committee on Cancer (AJCC) T4 N0 M0 (stage II), and underwent a right hemicolectomy. Fourteen months later he developed a firm 2.5-cm mass involving the chin. Excisional biopsy revealed moderately differentiated adenocarcinoma, consistent with the known colon primary tumor. Patient 2 is a 75-year-old man who was diagnosed with AJCC T3 N1 M0 (stage III) adenocarcinoma of the colon and underwent sigmoid colectomy. Ten years later, he was found to have transitional cell carcinoma involving retroperitoneal nodes with no identifiable bladder or ureteral primary, for which he received chemotherapy. Eighteen months following this diagnosis, he developed hematuria and was found to have metastatic colon adenocarcinoma involving the bladder. Details of both patient cases are presented here.