INTENTION: A lead in this study means an electric wire connected to an electric circuit at one point. Every part of a lead is equipotential because of the absence of current. This equipotentiality is termed the lead effect. We investigated through the recording of compound muscle action potentials (CMAPs) and electrocardiography (ECG) whether this characteristic nature of the lead is applicable in the human body. METHODS: First, we recorded CMAPs from two male persons connected to each other. Stimulation was delivered to subject 1 alone and subject 2 assumed the role of a lead. CMAPs of subject 1 were recorded from the abductor pollicis brevis muscle with the belly-tendon method. While subject 2 was touching the belly area of subject 1 with his right index finger, the potential was led from the left forearm of subject 2 with a reference on the tendon area of subject 1. When subject 2 was touching the tendon area, the potential was recorded from the belly area of subject 1 with a reference on the left forearm of subject 2. Second, we recorded ECG simultaneously from the two subjects connected to each other by their hands. RESULTS: The recording from the left forearm of subject 2 demonstrated potentials almost identical to the CMAPs of subject 1. This suggested that the potential at the area of subject 1 touched by subject 2 was ‘transmitted’ without significant alteration to the left forearm of subject 2, which was far from the generator of the CMAP. ECG activity of one person was also ‘transmitted’ to another. CONCLUSION: This study suggested that the human body works well as a lead. An area far away from a generator can register some potential through the lead or lead-like structure, such as extremities, and does not necessarily constitute an inactive site.

A 70-year-old man was referred to our department due to left pneumothorax associated with a thin-wall cavitary lesion in the S³ segment of the left lung. Surgical resection of the cavitary lesion was performed, which incidentally detected the development of squamous cell carcinoma around the cavity. Four and 7 months after the surgery, computed tomography (CT) of the chest revealed the development of thin-wall cavitary lung lesions associated with recurrent pneumothorax and the surgical specimens were also found to be composed of squamous carcinoma tissues around the cavities. CT before the third surgery revealed multiple intrapulmonary and hepatic metastatic tumors. As the tumors strongly expressed PD-1, the patient was treated with pembrolizumab, leading to a favorable response. Lung cancer may cause the formation of thin-wall cavities by the check valve mechanism and/or ischemic necrosis. On the other hand, pneumothorax may develop from the check valve mechanism and/or infiltration of carcinoma cells into the pleura. This report suggests that, when an elderly patient with smoking history presents with pneumothorax, the possibility that lung cancer underlies the condition should be considered.

A woman in her seventies presented with leukocytosis. Her white cell count was 33.87 × 10³/μL with 80.5% leukemia cells. Her bone marrow was replaced with peroxidase-negative leukemia blasts that were CD10^+/−, CD19⁺, CD20⁻, CD13⁺, CD33^−/dim, CD34⁺, CD117^−/dim, CD66c^+/−, cytoplasmic (cy-) CD79a⁺, terminal doxynucleotidyl transferase⁺, and cy-IGHM⁻. G-banding revealed t(9;22)(q34;q11.2) as the sole chromosome abnormality, and reverse transcriptase polymerase chain reaction (PCR) and nucleotide sequencing confirmed that the fusion encompassed exon 19 of BCR and exon 2 of ABL1, which generate p230 micro (μ)-BCR-ABL1 mRNA. We treated her with a second-generation tyrosine kinase inhibitor, dasatinib, in combination with low-intensity chemotherapy (vincristine and dexamethasone) followed by consolidation, leading to a hematological complete response (CR) and 10⁻⁴ level reduction of leukemia cell burden as measured by LightCycler^®-based real-time quantitative PCR assay. The patient received maintenance treatment with dasatinib followed by ponatinib and achieved hematological CR for 2 years and 8 months. This report showed that patients with the p230 μ-BCR-ABL1 fusion gene may present with not only chronic myeloid leukemia with mild clinical features but also Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL) with precursor B-cell immunophenotype; moreover, dasatinib-based induction, consolidation, and maintenance therapies are as effective for Ph+ ALL with μ-BCR-ABL1 as those with minor- and major-BCR-ABL1.

We report a case of delayed pharyngeal perforation, a rare complication of anterior cervical spine surgery, which was successfully treated by the closure of the perforated pharynx. A 62-year-old male patient presented with dysphagia. Six years earlier, he had undergone an anterior cervical spine surgery for ossification of posterior longitudinal ligament. Eight months after the initial presentation, he had further difficulty in swallowing and needed to change his diet to a grueling diet and crush his oral medication. He was admitted to the internal medicine department when fluid intake became difficult. Upper gastrointestinal endoscopy revealed that the anterior cervical spine plate was exposed at the esophageal orifice, leading to a diagnosis of delayed pharyngeal perforation caused by the plate. He was then referred to our department. We withdrew the plate, closed the pharyngeal perforation by simple suture, and applied a sternohyoid muscle flap to reinforce the closure. The patient had no complications postoperatively, and swallowing rehabilitation was started two weeks after the surgery. The patient initially received tube feeding, but recovered to the level of full oral intake by one month after surgery. Perforation of the pharynx or esophagus is well known as a serious complication of anterior cervical spine surgery, but there are few reports of delayed occurrence. Although closure using free tissue fragments or two-stage surgery should be considered depending on the size and location of the perforation and the underlying condition of the patient, in the present case, it was possible to treat the patient with a single-stage minimally invasive surgery without causing pharyngeal stenosis or postoperative re-perforation.

A man in his seventies presented with a bulky abdominal tumor. The level of lactate dehydrogenase was 3,854 U/L, uric acid was 11.1 mg/dL, and soluble interleukin-2 receptor was 5,750 U/mL (reference range, 145 to 519 U/mL). The bone marrow (BM) was infiltrated with large cells with features of Burkitt lymphoma, whereas lymphoma cells in the peripheral blood (PB) exhibited indolent cytomorphology indicative of follicular lymphoma (FL). Multicolor flowcytometry and fluorescence in situ hybridization revealed that BM lymphoma cells were CD10⁺, CD24^bright, and CD38^bright and had t(14;18)(q32;q21)/BCL2-IGH and t(8;14)(q24;q32)/MYC-IGH. In contrast, the majority of PB lymphoma cells were small to medium sized and CD10⁻, CD24^−/dim, and CD38⁻ and had t(14;18)/BCL2-IGH but lacked t(8;14)/MYC-IGH, and we identified a intermediate population composed of medium-sized cells that were CD10^dim, CD24^dim/+, and CD38⁺ and had both t(14;18)/BCL2-IGH and t(8;14)/MYC-IGH. Multiplex polymerase chain reaction confirmed that BM and PB lymphoma cells shared common IGK rearrangement and BCL2-IGH fusion sequence. It is indicated that, in this case, indolent FL and MYC/BCL2 double-hit high-grade B-cell lymphoma (HGBL) transformed from FL developed concurrently and acquisition of t(8;14)/MYC-IGH may not immediately lead to transformation to HGBL, but instead, florid cytomorphologic transformation may occur in BM.

Statistical processing of data is necessary when planning the implementation of a clinical study, submitting a paper, or presenting results at a conference. In such situations, it is often difficult to determine the statistical method to use. This study outlines a basic method for selecting an appropriate statistical method from the viewpoint of type of analysis (univariate, multivariate), whether the data is paired or unpaired, type of variable (continuous, ordinal, nominal), type of distribution (parametric, non-parametric), number of groups, and number of samples.