A Rare Case of Adenocarcinoma With Micropapillary Structure and Apocrine Differentiation Arising in a Sebaceous Tumor.

ABSTRACT: A 77-year-old Japanese man presented to our hospital with subcutaneous tumors of the right upper arm and axilla. A biopsy revealed a cutaneous adnexal tumor, showing apocrine differentiation, and axillary lymph node metastasis. After chemoradiotherapy to shrink the tumors, both lesions were resected. A resected specimen of the arm tumor showed a variegated histology: (1) a classic sebaceoma with an organoid pattern and sebocytes; (2) a sebaceous tumor with cellular atypia; (3) a papillotubular tumor showing a biphasic pattern of pale eosinophilic cells with apocrine differentiation and basaloid cells; and (4) an invasive adenocarcinoma with a micropapillary structure, reminiscent of an invasive micropapillary carcinoma of the breast. The axillary tumor was regressed. To our knowledge, this is the first reported case of an adnexal tumor of the skin with an invasive micropapillary structure arising in a sebaceous tumor.

Application of fluorescence in situ hybridization in distinguishing acral melanoma in situ from acral junctional melanocytic nevus on the volar skin in Japanese patients.

Four-colored fluorescence in situ hybridization (FISH) is an ancillary diagnostic tool for melanoma. However, most studies that have investigated the usefulness of FISH primarily focused on advanced melanomas. The aim of the current study was to evaluate the effectiveness of FISH in distinguishing acral melanoma (AM) in situ from benign acral junctional nevus (AJN), two types of lesions that are difficult to differentiate via traditional clinical means. The authors investigated the usefulness of FISH in 91 acral melanocytic lesions, including 50 lesions with diagnostic discrepancies between dermoscopic and pathologic approaches or difficulty diagnosing between AM in situ and AJN, on the volar skin of Japanese patients. The authors classified the lesions based on the diagnosis of dermatologists and pathologists into four groups: (I) lesions with a unanimous diagnosis by dermatologists and pathologists as AM in situ or AJN (n = 41); (II) lesions with a unanimous diagnosis by dermatologists only as AM in situ or AJN (n = 21); (III) lesions with a unanimous diagnosis by pathologists only as AM in situ or AJN (n = 15); and (IV) all other lesions (n = 14). The dermatologists diagnosed the lesions by clinical and dermoscopic photographs alone, while the pathologists diagnosed the lesions by microscopy of hematoxylin and eosin-stained slides alone. In group I (AM in situ [n = 20] and AJN [n = 21]), four-colored FISH demonstrated 90% sensitivity and 81% specificity in distinguishing AM in situ from AJN. There was a significant correlation between the FISH results and the unanimous diagnoses by pathologists alone (p = 0.03) in group III. However, FISH results were not significantly correlated with the unanimous diagnoses by dermatologists alone (p = 0.33) in group II. In conclusion, the four-colored FISH probe kit was useful in distinguishing between AM in situ and AJN and may be an ancillary method when pathologists who are not experts of dermatopathology diagnose melanocytic lesions.

Hyperplastic melanocytes with chromosomal aberrations in surrounding skin of subungual melanoma: fluorescence in situ hybridisation analysis using whole-slide digital imaging.

AIMS: Subungual melanoma (SUM) is increasingly being treated with conservative surgery. Consequently, the evaluation of the resection margins has increased in importance. However, in several cases it is difficult to distinguish the in-situ lesion of SUM from hyperplastic melanocytes in the surrounding skin. We examined whether PReferentially expressed Antigen in MElanoma (PRAME) immunohistochemistry and fluorescence in situ hybridisation (FISH) labelling of CCND1 (11q13), RREB1 (6p25), MYB (6q23), and centromere 6 (CEP6) genes differentiated SUM from hyperplastic melanocytes. METHODS AND RESULTS: We reviewed specimens of 36 SUM cases and compared PRAME immunostains of invasive melanoma, melanoma in situ, and hyperplastic melanocytes. PRAME-positive cases accounted for 90.5% of invasive melanoma, 88.9% of in situ melanoma, and 59.4% of hyperplastic melanocyte specimens. While invasive and in situ melanomas in more than half of the examined cases were diffusely positive, this was found for only 9.4% of hyperplastic melanocyte cases. Four-coloured FISH using whole-slide digital imaging was used to analyse positive detection rates and changes in chromosomal aberrations. The FISH positive detection rate was 100% in invasive melanomas, 94.7% in melanomas in situ, and 66.7% in hyperplastic melanocytes. The number of RREB1 (6p25) signals per cell was significantly amplified following tumour progression. CONCLUSION: Hyperplastic melanocytes in the surrounding skin of SUM, considered morphologically non-neoplastic, showed chromosomal aberrations similar to those in melanoma. Such cells are also thought similar to the field cells of acral melanomas. Thus, whole-slide digital imaging is a technique that allows the evaluation of individual melanocyte lesions by FISH.

Bendamustine-induced rash is associated with a favorable prognosis in patients with indolent B-cell lymphoma.

Bendamustine is now recognized as a key drug for indolent B-cell lymphoma (iBCL), mantle cell lymphoma (MCL) and chronic lymphocytic leukemia (CLL). Skin toxicity associated with bendamustine is one of the characteristic adverse effects. We retrospectively examined the relationship between bendamustine-associated drug rashes and disease prognosis of iBCL and MCL at our institution. Between January 2011 and August 2019, 65 patients (39 men and 26 women, median age 68, range 41-84 years) were treated with bendamustine alone (n=11, 120 mg/m2 on days 1 and 2) or a combination of rituximab and bendamustine (n=54, 90 mg/m2 on days 1 and 2). Of these patients, 47 had follicular lymphoma (FL), 10 had MCL and 8 had other iBCLs. Drug rash occurred in 27 (41.5%). Eight cases (29.6%) were grade 1, 5 (18.5%) were grade 2 and 14 (51.9%) were grade 3. The onset was in the first course in 17 (63.0%), 2nd course in 5 (18.5%), 3rd course in 2 (7.4%), 4th course in 1 (3.7%) and 5th course in 2 (7.4%). No treatment was administered in 1 case (3.7%), topical steroid was applied in 10 (37.0%), antiallergic drug was administered in 2 (7.4%), topical steroid and antiallergic drug were administered in 5 (18.5%), and oral and topical steroid and antiallergic drug were administered in 9 (33.3%). The 3-year progression-free survival (PFS) and overall survival (OS) in patients with rash development were 80.0% and 85.5%, respectively, and those in patients without development were 36.4% and 54.0%, respectively (p=0.009 and 0.02, respectively). By multivariate analysis, the development of rash was associated with a better PFS and a diagnosis of iBCL was associated with a better OS. This study revealed that bendamustine-induced rash is associated with a favorable prognosis among patients with iBCL.

A case of dermatofibrosarcoma protuberans with neurofibromatous change.

A 31-year-old man with posterior neck mass visited a hospital. The mass recurred four times on the same location during the past 6 years. Needle biopsy diagnosis was suspicious for benign stromal tumor. Tumor excision was performed 3 months after the biopsy. The tumor size was 8.3 × 4.5 cm and was located at subcutaneous tissue. Histologically, main tumor cells showed comma-shaped nuclei, which are same as neurofibroma. Immunohistochemically, tumor cells were positive for vimentin, CD34, but were negative for S-100. Fluorescence in situ hybridization analysis disclosed a split signal of PDGFB gene. Reverse transcriptase-polymerase chain reaction clarified COL1A1 exon 47/PDGFB exon 2 chimeric gene. Final diagnosis was dermatofibrosarcoma protuberans (DFSP) with neurofibromatous change. DFSP with neurofibromatous change is rare and could be misdiagnosed as benign tumor, especially in a biopsy specimen. Molecular diagnosis is a promising aid in a challenging case and in biopsy specimens.

Diagnosis of Pancreatic Solid Lesions, Subepithelial Lesions, and Lymph Nodes Using Endoscopic Ultrasound.

Currently, endoscopic ultrasound (EUS) has become widely accepted and has considerable advantages over computed tomography (CT) and other imaging modalities, given that it enables echostructure assessment in lesions with <1 cm diameter and permits high resolution imaging. EUS-guided tissue acquisition (EUS-TA) provides consistent results under ultrasound guidance and has been considered more effective compared to CT- or ultrasound-guided lesion biopsy. Moreover, complication rates, including pancreatitis and bleeding, have been extremely low, with <1% morbidity and mortality rates, thereby suggesting the exceptional overall safety of EUS-TA. The aggressive use of EUS for various lesions has been key in facilitating early diagnosis and therapy. This review summarizes the diagnostic ability of EUS for pancreatic solid lesions, subepithelial lesions, and lymph nodes where it is mainly used. EUS has played an important role in diagnosing these lesions and planning treatment strategies. Future developments in EUS imaging technology, such as producing images close to histopathological findings, are expected to further improve its diagnostic ability. Moreover, tissue acquisition via EUS is expected to be used for precision medicine, which facilitates the selection of an appropriate therapeutic agent by increasing the amount of tissue collected and improving genetic analysis.

Normolipemic xanthomatized Sweet's syndrome: A variant of Sweet's syndrome with myelodysplastic syndrome.

We report a rare case of xanthomatized Sweet's syndrome with myelodysplastic syndrome (MDS) in a patient who presented with erythematous plaques on his chest that were elevated and became yellowish. A diagnosis of MDS with single lineage dysplasia was made during the development of the eruption. Bone marrow biopsy showed an increased number of megakaryoblasts. Histopathologically, there was neutrophil infiltration with leukocytoclasia and the infiltration of xanthomatous cells. Immunohistochemical analysis revealed that the xanthomatized cells were predominantly CD163 positive. We propose that our case of xanthomatized neutrophilic dermatosis is a rare clinicopathological variant of Sweet's syndrome associated with a hematologic disorder.

Distribution of CD1a-positive cells is not different between pseudolymphomatous folliculitis and primary cutaneous marginal zone lymphoma.

Pseudolymphomatous folliculitis (PLF) is a subtype of cutaneous pseudolymphoma that is recognized as an independent disease. PLF is characterized by dermal lymphocytic infiltration surrounding an irregular hyperplastic pilosebaceous unit (i.e., activated pilosebaceous unit). An interstitial distribution of CD1a-positive cells is regarded as an important feature of PLF, especially in distinguishing it from primary cutaneous marginal zone lymphoma (PCMZL), which is associated with a peripheral concentration of CD1a-positive cells. We undertook a clinicopathological investigation of PLF, with a reassessment of CD1a immunohistochemistry. We defined diagnostic criteria for PLF based on past studies and consequently identified 79 cases. In addition, we collected 32 cases of PCMZL and performed detailed clinical, pathological, and immunohistochemical investigations using antibodies to CD3, CD20, and CD1a. We found an interstitial concentration of CD1a-positive cells in 90.2% of PLF and 34.5% of PCMZL cases. The peripheral concentration of CD1a-positive cells was seen in 9.8% of PLF and 34.5% of PCMZL cases. In both diseases, CD1a-positive cells appeared in T-cell nests (88.5% in PLF and 92.9% in PCMZL) but were absent in B-cell nests (0% in both groups). All 79 cases of PLF showed activated pilosebaceous units while 22 of the 32 PCMZL cases displayed pilosebaceous units, although none of these were activated. In summary, regarding the distribution patterns of CD1a-positive cells as a diagnostic feature in distinguishing between PLF and PCMZL is somewhat inconclusive. To differentiate PLF and PCMZL, determining the presence or absence of activated pilosebaceous units is essential.

Indolent T-cell lymphoproliferative disorder of the stomach successfully treated by radiotherapy.

Successful treatment of indolent T-cell lymphoproliferative disorder of the gastrointestinal tract (ITLPDGI) by chemotherapy is rare and watchful waiting is often performed for asymptomatic patients. We report a case of ITLPDGI successfully treated by involved field radiotherapy (IFRT). The patient presented with slow ITLPDGI localised to the stomach with mild symptoms. IFRT (30 Gy/20f) was administered, after which endoscopy revealed resolution of lesions and blood vessel appearance, and absence of proliferating abnormal lymphocytes was confirmed by biopsy. The patient remains lymphoma-free 1 year post-treatment. Although long-term follow-up and additional cases are essential for the evaluation of IFRT as a treatment option for localised ITLPDGL, complete remission after relatively low-dose IFRT is promising, particularly as this has been rarely achieved by chemotherapy.

Primary cutaneous localized/clearly-outlined true histiocytic sarcoma: Two long-term follow-up cases.

Histiocytic sarcoma (HS) is a rare hematopoietic tumor that mainly involves extranodal sites, including the intestinal tract, skin, soft tissues and other organs. It is well known as an aggressive neoplasm that shows a poor response to therapy. However, a subset of patients with resectable disease has shown a favorable outcome with surgical treatment. Primary cutaneous HS is exceedingly rare and, to date, its long-term prognosis has thus not been well described. Here, we highlight two cases of primary cutaneous HS that showed long-term survival. Case 1 was a healthy 47-year-old woman who found a 12-mm tumor on her forehead. Case 2 was a 66-year-old woman, under follow up of a myxoid liposarcoma in her leg, who presented with a 25-mm tumor in her hypothenar eminence. Histologically, the tumors in both cases had a smooth outline with proliferating atypical tumor cells that showed histiocytic differentiation as revealed by immunohistochemistry with antibodies to CD68 (KP-1) and lysozyme in case 1; and CD68, lysozyme and CD163 in case 2. Tumor cells in case 1 had a monotonous appearance. After complete resection, cases 1 and 2 have survived for 10 and 4 years, respectively, without recurrence. To date, such patients are relatively long follow-up cases of survival from HS and highlight how a clear outline of the primary cutaneous HS tumor may be associated with its resectability and be an important factor in the assessment of its curability.

Peripheral T-cell lymphoma with gastrointestinal involvement and indolent T-lymphoproliferative disorders of the gastrointestinal tract.

The 2017 WHO classification includes a new provisional entity of indolent T-lymphoproliferative disorders of the gastrointestinal tract (ITLPD-GIT). We investigated GI involvement of peripheral T-cell lymphoma (PTCL). Eighty-two patients were diagnosed with PTCL during 2007-2017. Eleven patients (13 %) had histologically-confirmed GI tract involvement {3 monomorphic epitheliotropic intestinal lymphoma (MEITL), 3 extranodal NK-/T-cell lymphoma nasal type (ENKL), 2 PTCL, not otherwise specified, 1 adult T-cell leukemia-lymphoma, 2 ITLPD-GIT}. Three patients each had lesions in the small intestine and multiple lesions, two each in the stomach and colon, and one in the duodenum. Six of the 11 patients remained alive. No perforation/stenosis was observed after chemo-radiotherapy, although one patient with ENKL developed gastric bleeding during chemotherapy. One patient with ITLPD-GIT (CD4-/CD8+/Ki67Low) with a colonic lesion showing diffuse edema and multiple aphtha by endoscope and diarrhea, initially diagnosed with MEITL, had active but stable disease after various chemotherapies for 1 year and no therapy for the next 5 years. Another patient with ITLPD-GIT (CD4+/CD8+/Ki67Low) with a localized gastric lesion and slight epigastralgia was in remission for 1 year after radiation. In conclusion, about 10 % of PTCLs were complicated by GI tract lesions and most had a poor prognosis. ITLPD-GIT should be considered as a differential diagnosis based on histology and clinical course. Local complications after chemo/radiotherapy in PTCL with GI involvement were not frequent.

[Case of isolated neurosarcoidosis requiring differentiation from tuberculous meningitis].

A 62-year-old woman was transported to our hospital for management of generalized clonic seizures. Cerebrospinal fluid examination showed an increased monocyte-dominant cell count, high protein concentration, and low glucose concentration that was 17% of the plasma glucose concentration. Contrast-enhanced cranial magnetic resonance imaging revealed diffuse leptomeningeal enhancement with multiple nodular lesions. She underwent examinations that ruled out the following conditions: tuberculous meningitis, systemic sarcoidosis, malignant lymphoma, carcinomatous meningitis, and central nervous system vasculitis. On hospital day 13, dural and brain biopsies revealed neurosarcoidosis, for which steroid therapy was administered. Thereafter, imaging examinations showed marked improvement. Because isolated neurosarcoidosis is difficult to diagnose, early pathologic diagnosis may be essential.

A case of acute cerebral infarction associated with an accessory middle cerebral artery in a patient who underwent thrombectomy.

BACKGROUND: The accessory middle cerebral artery (AMCA) is a middle cerebral artery (MCA) anomaly originating from the anterior cerebral artery. We report our experience of a case in which thrombectomy was undertaken for a patient with hemodynamics that were specific to the AMCA. CASE PRESENTATION: An 84-year-old man with a history of atrial fibrillation developed paralysis of the left upper and lower extremities. Imaging examinations suggested tandem occlusion of the right internal carotid artery and the origin (M2 segment) of the right MCA. An extremely narrow MCA was visualized. Because there was concern regarding development of frontal lobe infarction, thrombectomy was carried out to restore anterograde blood flow, but an AMCA was found. Recanalization of the main MCA in the infarction zone resulted in hemorrhagic infarction, and the patient died of cerebral herniation. CONCLUSION: When a vascular variation like AMCA is suspected, a careful evaluation of hemodynamics is necessary before undertaking endovascular intervention.

Pulmonary intravascular large B-cell lymphoma accompanying synchronous primary pulmonary adenocarcinoma and benign interstitial lesions.

Intravascular large B-cell lymphoma (IVLBCL) is a rare type of extranodal large B-cell lymphoma, and initial or predominant presentation in the lungs is uncommon. The synchronous occurrence of IVLBCL and malignant tumors is less frequent, and no such reports have described pulmonary presentations. We report a rare case of pulmonary IVLBCL accompanying lung cancer and interstitial lesions. A 73-year-old man with a history of pneumonia underwent a follow-up examination. Computed tomography revealed diffuse, bilateral ground-glass opacities (GGO) with a partial solid mass. Histologically, the mass consisted of adenocarcinoma. However, two other types of interstitial lesions were scattered throughout the resected lung: 1) peribronchovascular thickening with the aggregation of macrophages and anthracosis, and 2) alveolar septal thickening in the centrilobular area with atypical CD20-positive large cells in the capillaries. These two types of lesions were not mixed. Computed tomography and positron emission tomography demonstrated no other organ involvement. The patient was considered to have the synchronous occurrence of pulmonary IVLBCL and lung cancer (adenocarcinoma). After R-CHOP therapy, GGO on CT disappeared. Lung cancer often accompanies benign background lesions, and the combination of these lesions with lung cancer may make it difficult to detect the presence of pulmonary IVLBCL. However, the histological distribution pattern of IVLBCL may be a clue to the correct diagnosis.