Tadashi Terada

Primary cutaneous keratinocytic primordial carcinoma with triple differentiations into basal cell carcinoma, sqaumous cell carcinoma, and porocarcinoma

The author herein reports a hitherto undescribed entity of cutaneous primordial carcinoma with triple differentiation into basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and porocarcinoma (PC) in a 66-year-old man. The patient was treated by tumor excision with wide margins. Pathologically, the margins were negative for tumor cells. The patient is now healthy 1 year after the excision. The tumor measured 3 cm × 2 cm × 2 cm and arose from the epidermis. The percentage of the occupying area was 60% in BCC, 20% in SCC, and 20% in PC. Histologically, BCC was characterized by basalioma cells, melanin pigmentation, peripheral palisading, and cleft formation, SCC by ample acidophilic cytoplasm, individual keratinization and cancer pearls, and PC by poroma cells and tubular structures containing cuticles. Cystic changes in BCC and SCC, keratotic nature of BCC, and acatholytic features of SCC were also seen in places. There were gradual merges among the three components. Immunohistochemically, BCC component was characterized by strong and diffuse expression of KIT, PDGFRA and p63, weak expressions of cytokeratin (CK) AE1/3, CK CAM5.2, CK34BE12, and negative expressions of CK18, CK19, CEA and CA19-9. SCC component was characterized by strongly positive expressions of p63, CEA, CK34BE12, CK7 and CK8, and negative expressions of CK18, CK19, and CA19-9. PC was characterized by strongly positive expressions of KIT, PDGFRA, CK34BE12, CK7, CK8, CK18, CK19, CEA, S100 protein, CA19-9, MUC1, and negative expression of p63. The present case revealed that there are primary cutaneous keratinocytic primordial carcinomas with triple differentiations into BCC, SCC, and PC. The present case is the first example of such tumors. It is thought that KIT and PDFRA-positive stem cells or cancer stem cells in the BCC component give rise to the SCC and PC components in the present case.

Occult prostatic adenocarcinoma presenting as a ureteric tumor and expressing KIT and PDGFRA

Prostatic carcinoma (PC) may present multiple metastases of unknown primary (most commonly bone metastases), the occult PC. PC expressing KIT and PDGRA has not been reported. There have been no reports of occult PC manifesting as a ureter tumor. An 83-year-old man presented with flank pain. Imaging showed a ureter tumor. Ureteronephrectomy was performed. The author diagnosed the ureteric tumor as high-grade urothelial carcinoma, Postoperative imaging showed multiple tumors in liver and lymph nodes. The clinical diagnosis was hepatocellular carcinoma and cirrhosis, and the patient received radiofrequency ablation (RFA). The patient further presented hematuria, and cystscopy revealed an elevated tumor of urinary bladder, and TUR-BT was performed. Histologically, TUR-BT specimens show monotonous medullar proliferation of high-grade malignancy arranged in solid nests and acinar formations. Immunohistochemically, tumor cells were positive for PSA, α-methyl CoA racemase (AMACR), cytokeratin (CK) AE1/3, CK CAM5.2, CK8, CK18, CK19, CEA, synaptophysin, KIT, PDGFRA, p53 and Ki-67 (labeling index = 90%). No mutations of KIT and PDGFRA were noted. Since PSA and AMACR were positive, the definite diagnosis of PC (Gleason 9) metastatic to multiple sites including ureter and bladder was made.

Primary cutaneous extra-nodal NK-cell lymphoma, nasal type

Primary extra-nodal NK-cell lymphoma of skin is extremely rare. A 55-year-old man presented with an elevated plaque of trunk. The dermatologists’ diagnosis was sporotrycosis and a biopsy was taken, which showed diffuse dense infiltrations of medium-sized and large atypical malignant lymphocytes. Epidermal hyperplasia and erosions were also seen. Immunohistochemically, the atypical lymphocytes were positive for CD45, CD56, CD57, p53 and Ki-67 (labeling index = 82%). They were negative for CD20, CD79, CD10, bcl-2, κ-light chain, λ-light chain, CD3, CD4, CD5, CD21, CD23, CD38, CD43, CD68, CD138, CD15, CD30, TdT, and cyclin D1. EBER was positive. The pathological diagnosis was primary cutaneous NK-cell lymphoma, nasal type. The post-biopsy blood test identified no leukemia findings. Post-biopsy imaginings revealed no mass and lymphadenopathy in the body. The skin lesions of the patient almost improved (complete remission) by chemotherapy (CHOP) followed by local radiation, and the patient is now followed up.

Perineuroma of the skin negative for S100 protein but positive for stem cell antigens: A possible stem cell tumor

Perineuroma is a rare tumor originating from perineurium of the peripheral nerve. In contrast to neurofibroma and schwannoma, both of which arise from endoneurium and are immunohistochemically positive for S100 protein, perineuroma is negative for S100 protein; the fact makes the pathologic diagnosis difficult. As is well known, stem cells are highly associated with neuronal and organ developments in human embryos, and some neuronal cells are suspected to be derived from neuronal stem cells. Herein reported a very rare case of subcutaneous perineuroma negative for S100 protein but positive for a number of stem cell antigens; the case suggested that some perineuromas could arise from neuronal stem cells. A 68-year-old woman presented with a skin tumor of 10 mm in diameter in the foot. Physical examination revealed a small movable subcutaneous tumor, and resection was performed. Histologically, the tumor was a well-defined round tumor measuring 0.9 cm × 0.9 cm × 0.9 cm located in the subcutaneous tissue. No capsule was seen. The tumor was composed of hypocellular myxoid, neuroid tissues containing small areas of high cellularity where tumor cells resembled neuronal stem cells. Immunohistochemically, the tumor was negative for S100 protein, HMB-45, various cytokeratin (CK), EMA, α-SMA, desmin, p53, and many other antigens. The neuronal stem cell-like cells were positive for various stem cell antigens including NSE, KIT, bcl-2, chromogranin, synaptophysin, PDGFRA, MET, ErbB2, and CD34, as well as for vimentin and Ki-67 antigen (labeling index = 1.5%). Because the tumor was negative for S100 protein but positive for neuroendocrine molecules and neuronal stem cell antigens, the author diagnosed the tumor as perineuroma with stem cell features. Such a perineuroma has not been reported to date. The outcome of the patient was excellent.

Tubulo-villous adenoma with severe dysplasia in the prostatic urethra: A case report and histogenetic considerations

In 2002, Seibel et al. presented a case series of 18 patients with villous adenomas of the urethra. Since then, only a couple of reports regarding this rare entity have been published. Recently (2013), Kao and Epstein proposed a new entity of tubular adenoma (4 cases) in the urinary tract, being similar to tubular adenomas in gastrointestinal (GI) tract; no following cases have been reported. Herein presented a case of tubule-villous adenoma (TVA) in the prostatic urethra (PU) of a 77-year-old man male patient suffering from dysuria. Cystscopy showed a polypoid/villous tumor of the PU, and transurethral resection of this tumor was performed. Grossly, fragments of the tumor measured 12 mm in diameter and polypoid/villous. Microscopically, it was a TVA indistinguishable from GI adenomas. No urothelium was seen, but a few normal prostatic glands were noted. The tumor showed mild to severe dysplasia, but in situ malignant transformation and invasive malignancy were not seen. Histochemically, acidic mucins were present. Immunohistochemical staining results of the tumor cells were as follows: cytokeratin(CK) AE1/3+++, CKCAM5.2+++, CD34BE12+, CK5+, CK6+, CK7++, CK14-, CK20+, EMA+, CDX-2-, CEA++, CA19-9++, CA125-, vimentin-, NSE-, NCAM-, synaptophysin-, chromogranin-, E-cadherin+++, beta-catenin+++, MUC1++, MUC2-, MUC5AC++, MUC6+, PSA+++, AMACR+++, AFP-, HepPar1-, p53-, KIT-, PDGFRA+, MET+, HER2-, Ki67+ (labeling = 5%). Myoepithelial cells were present in some areas. These results suggest the development and presence of a TVA in the PU indistinguishable from those in the GI tract, and it can arise from prostatic epithelium.