Paraneoplastic polymyositis presenting as a clinically occult breast cancer

The decreased serum activity of cytosolic 5'-nucleotidase IA as a potential marker of breast cancer-associated muscle inflammation

Cytosolic 5'-nucleotidase IA (cN-IA) plays a central role in the regulation of the purine nucleotide pool in skeletal muscle, preferentially converting adenosine monophosphate to adenosine. cN-IA can act as an autoantigen in muscle diseases, including the paraneoplastic syndrome related to breast cancer (BC). As a result of myocyte damage, released cN-IA protein may trigger the production of anti-cN-IA antibodies (anti-NT5C1A). This work aimed to develop an effective method to measure cN-IA activity in the serum and analyze it in BC patients. Our study demonstrated that serum cN-IA activity was decreased in BC patients and we assumed it is due to the presence of specific autoantibodies. We found correlations between cN-IA activity and parameters of inflammatory muscle damage. Thus, cN-IA is worth further attention to clarify its usefulness as a biomarker of BC-associated polymyositis.

Paraneoplastic myopathy in pancreatic cancer: a case report and literature review

Dermatomyositis (DM) and polymyositis (PM) are both immune-mediated inflammatory myopathies known to occur in paraneoplastic syndromes associated with a new diagnosis of malignancy, most commonly breast, ovarian, lung, pancreatic, stomach, colorectal, and Non-Hodgkin’s lymphoma¹ in DM and breast, lung, bladder cancer, and Non-Hodgkin’s lymphoma in PM. ^2,3,4 While inflammatory markers such as creatine kinase (CK) may be elevated with either DM or PM, marked elevation is rare. Herein, we report a case of newly diagnosed pancreatic cancer presenting with inflammatory myopathy and marked CK elevation. We review the frequency of PM as a paraneoplastic syndrome, the association with marked CK elevation, and the association with pancreatic cancer.

Anemia and thrombocytopenia as initial symptoms of occult breast cancer with bone marrow metastasis: A case report

RATIONALE

Occult breast cancer (OBC) is a rare type of breast cancer without any symptoms in the breast and is often presented with initial symptoms of axillary lymph node metastasis or other metastases. The low incidence rates of OBC make it a great challenge to diagnose and cure.

PATIENT CONCERNS

Our case was a 58-year-old female affected by dizziness and fatigue for nearly a month. Blood tests revealed anemia and thrombocytopenia, and pathological results of a bone marrow biopsy confirmed the metastatic carcinoma.

DIAGNOSES

It was diagnosed as an OBC based on the positive immunohistochemical staining of cytokeratin (CK) and gross cystic disease fluid protein-15 (GCDFP-15).

INTERVENTIONS

Doctor advised her to check whether the bone metastases existed in order to choose an appropriate treatment. It is highly regrettable that the patient gave up all treatments and left the hospital.

OUTCOMES

Recently, we conducted a telephone follow-up and received that the patient only took tramadol and other painkilling drugs to alleviate the pain caused by cancer.

LESSONS

The current case inferred that symptoms of anemia and thrombocytopenia should not be ignored for the diagnosis of OBC, and bone marrow biopsy is useful in reducing the rates of misdiagnosis and missed diagnosis of OBC.

A Unique Case of Muscle-Invasive Metastatic Breast Cancer Mimicking Myositis

Breast cancer rarely metastasizes to the muscles, and it is even more unusual for this phenomenon to result in airway compromise. We present a unique case of an 84-year-old female who presented with neck swelling and upper airway obstruction due to metastatic breast cancer invading the sternocleidomastoid muscles. After establishing the diagnosis and discussing possible treatment options, the patient elected for antiestrogen therapy, palliative tracheostomy, radiation therapy, and hospice services.