Evolution of an Orbital Apex Tumor Over a Decade

We report the evolution of an orbital apex tumor that underwent spontaneous regression, followed several years later by rapid growth and loss of vision. A turkey farmer had a right apical lesion, initially thought to be an optic nerve meningioma. The mass spontaneously regressed over 2 years, with marked improvement of vision. Eight years later, the patient presented with loss of light perception and severe proptosis of the right eye from a massive orbital tumor that extended in the cavernous sinus. An eyelid-sparing orbital exenteration was performed. The pathologic diagnosis was diffuse large cell lymphoma. This case demonstrates that non-Hodgkin lymphoma of the orbital apex may resolve spontaneously or it may enlarge rapidly, degenerating into more aggressive forms.

Clinically equivocal melanocytic skin lesions with features of regression: a dermoscopic-pathological study

BACKGROUND

Benign melanocytic skin lesions may be difficult to differentiate from melanoma both clinically and dermoscopically. One of the most confounding dermoscopic features, commonly seen in melanoma but in our experience also in melanocytic naevi, is represented by the so-called blue-white structures (BWS).

OBJECTIVES

To evaluate diagnostic significance and histopathological correlates of BWS seen by dermoscopy in a series of clinically equivocal melanocytic skin lesions that were excised.

METHODS

Patients were recruited from six specialized pigmented lesion clinics in Austria, Italy and Spain over a period of 9 months. All consecutive patients showing one or more melanocytic lesions with BWS, but not classified as melanoma dermoscopically, were included. Each lesion was photographed clinically and dermoscopically. All images were reviewed by one of us and the degree, type and location of BWS evaluated for each lesion. A panel of four experienced dermatopathologists independently reviewed all specimens for diagnosis and one of them evaluated presence and degree of melanosis and/or fibrosis. The main outcome measures were the percentage and histopathological correlates of lesions with different degree, type and location of BWS.

RESULTS

All included lesions with BWS (n = 158) showed partial or focal regression histopathologically. One hundred and thirty-five (85.4%) lesions were diagnosed as melanocytic naevi (complete histopathological interobserver agreement), whereas 23 (14.6%) were defined as equivocal because at least one of four pathologists diagnosed the given lesion as melanoma. Only one lesion was diagnosed as melanoma by all four pathologists. The majority of naevi exhibited blue areas (84.4%) with a central distribution (57%) and involving < 50% of the lesion surface (89.6%). By contrast, 78.3% of equivocal lesions revealed a combination of white and blue areas with an irregular distribution (60.9%) and involving > 50% of the lesion surface (47.8%).

CONCLUSIONS

Using degree and type of BWS, an algorithm was constructed that can be applied for the management of lesions exhibiting dermoscopic features of regression.

Phagocytosis by dendritic cells rather than MHC IIhigh macrophages is associated with skin tumour regression

Dendritic cells (DC) are important for the induction of anti-tumour immunity and are currently being used in clinical trials. Whether DC in tumours behave the same as DC in normal tissues or whether the tumours subvert DC phenotype and function remains unknown. To address this, we have used a unique animal tumour model to compare the DC infiltrating regressing tumours with the DC infiltrating progressing skin tumours. Compared to progressor tumours, the regressor tumours were infiltrated by greater numbers of DC that were also less mature, based on MHC II expression. Apart from this, the phenotype of DC in both tumours was similar. However, compared to various control DC, they could not be classed as either mature or immature. Similar to terminally maturated DC but in contrast to fresh DC, tumour-derived DC did not express CCR5 or CXCR4, suggesting that they most closely resembled terminally matured DC. Macrophages that expressed high MHC II levels were found infiltrating progressor but not regressor tumours and in vivo were the major phagocytic cell. In contrast, DC were found to be the major phagocytic cell in regressor tumours. The results show that immune destruction and eventual regression of skin tumours occurs if DC rather than MHC II(high) macrophages are the major phagocytic cell.

Argon beam plasma coagulation as therapy for high-grade dysplasia in Barrett's esophagus

BACKGROUND & AIMS

Patients with high-grade dysplasia in Barrett's esophagus have a high chance of developing adenocarcinoma. Previously these patients have undergone resection, however, the management of patients unsuitable for surgical resection is unclear. We have studied the long-term outcome of patients who have undergone endoscopic Argon ablation for high-grade dysplasia in Barrett's.

METHODS

Twenty-nine patients (median age, 64 yr; range, 43-85 yr) with high-grade dysplasia in Barrett's, who were unfit or had declined surgery, underwent Argon ablation and received follow-up evaluation over 7 years (mean follow-up, 37 mo; range, 7-78 mo). Treatment was stopped once there was no further histologic evidence of dysplasia. The patients then went on to receive a surveillance endoscopy at 3, 6, and 12 months after ablation, then annually thereafter.

RESULTS

High-grade dysplasia responded to treatment in 25 patients (86%); 22 of these had complete regression to neosquamous esophageal mucosa. During follow-up evaluation, no patients died of esophageal adenocarcinoma. Four patients developed cancer, 3 of whom continue with ablation therapy. The fourth patient died of unrelated causes. A single esophageal perforation was the only significant adverse event attributable to therapy. No esophageal strictures occurred and patients returned to normal activity after 24 hours in the majority of cases. Patients who received Argon ablation showed no difference in survival to that of the general population.

CONCLUSIONS

Argon beam ablation for high-grade dysplasia in Barrett's esophagus is an effective and safe treatment, especially in patients unfit for surgical resection.

Autonomous histopathological regression of primary tumours associated with specific immune responses to cancer antigens

Spontaneous histopathological regression of cancer has been reported. The involvement of the immune system in such regression has been advocated, leading to the theory of immunological surveillance against cancer. A prediction of this theory is that common tumour antigens can be recognized upon repeated exposure by cell-mediated immunity, which leads to tumour regression and the subsequent appearance of tumour antigen-loss variants. However, no direct evidence has been provided in non-viral-induced experimental animal models of primary malignancy or in human primary cancer. This study examined two groups of melanoma patients where histopathological regression of the primary tumour was observed. Many of the 23 patients with multiple (> or =3) primary melanomas showed significant regression of their last melanoma (median 33%, mean 40) compared with matched melanomas from patients with a single primary melanoma (median 0%, mean 12) (p=0.0080), or compared with their first primary melanoma (p=0.0013). Regression was consistent with an 'immunization effect' seen in murine tumour transplantation studies, where inoculation with > or =3 asynchronous tumours induces transplantation rejection on subsequent challenge. A significant decrease in the expression of the melanoma common tumour antigen MART-1 in the last primary tumour from multiple melanoma patients (median 8%, mean 24) versus matched single melanoma patients (median 79%, mean 68) (p=0.0041) and in the last versus first tumour in multiple primary patients was found (p=0.0083). Metastases from 17 patients whose primary skin melanomas had completely regressed (occult primary melanoma) also showed significant MART-1 loss (median 0%, mean 11) compared with matched metastases from patients with non-regressing primary melanoma (median 51%, mean 50) (p=0.0013). MART-1 antigen-loss variants observed in the multiple primary and occult primary patients correlated with the presence of peripheral blood MART-1-specific cytotoxic T lymphocytes (CTLs) (p=0.03). No similar effects were observed with two other melanoma antigens, gp100 and CD63. Thus, in two groups of human melanoma patients, evidence is provided for histopathological tumour regression associated with cancer immune surveillance.

CD44 variant isoform v10 is expressed on tumor-infiltrating lymphocytes and mediates hyaluronan-independent heterotypic cell-cell adhesion to melanoma cells

CD44 is a family of cell-surface receptors on human lymphocytes that act as co-stimulatory molecules leading to the induction of effector functions in T cells. We have analyzed primary cutaneous malignant melanomas with clinical and histologic signs of tumor regression using immunohistochemistry and observed the predominant expression of the CD44 variant isoform v10 on CD3 CD4/CD8 co-expressing tumor-infiltrating lymphocytes (TIL). We further analyzed the role of CD44v10 in adhesion of lymphocytes to human melanoma cells. In contrast to CD44- lymphatic cells, CD44v10+ lymphatic cells strongly bound to cultured human melanoma cells and to frozen tissue samples of melanomas. Antibody blocking studies revealed a hyaluronan-, integrin-, and selectin-independent pathway of adhesion. Furthermore, CD44v10+ lymphatic cells exhibited significantly higher invasiveness in three-dimensional collagen matrices as compared with CD44H+ and CD44-negative lymphocytes. These results indicate that expression of CD44v10 on TIL may mediate adhesion to melanoma cells and result in gain of novel invasive properties.

Spontaneous recovery from a medulloblastoma by a female with Gorlin-Goltz syndrome

Gorlin-Goltz syndrome is characterized by nevoid basal cell carcinomas, odontogenic keratocysts of the jaws, palmar and plantar pits, falx calcifications, and various cancer susceptibilities attributed to a mutation in a tumor suppressor gene. We present an 11-year-old female with Gorlin-Goltz syndrome. A medulloblastoma was diagnosed when she was 4 years old. She received total excision of the tumor and adjuvant chemotherapy and radiotherapy. One year later, the tumor relapsed with cerebral spinal fluid seeding. She recovered spontaneously with no treatment, and she has not developed basal cell carcinoma within 6 years. This patient with Gorlin-Goltz syndrome had a good prognosis with regard to the medulloblastoma. Diagnosis of the syndrome should be made as early as possible to avoid aggressive radiotherapy that may induce basal cell carcinomas.

Spontaneous complete necrosis of hepatocellular carcinoma: a case report

Spontaneous regression of hepatocellular carcinoma (HCC) is rare. We found spontaneous regression of HCC in a 53-year-old Chinese with liver cirrhosis. A liver mass 3 cm in diameter was revealed by B-ultrasonography. The resected mass showed histologically complete necrosis. The necrotic tissue was filled with large debris from a neoplastic tissue, regardless of no viable tumor cells were seen among them. The postoperative course was uneventful, and the patient is alive and well for 4 years after surgery.

Expression of PPAR-gamma is correlated with the clinical course of neuroblastoma

BACKGROUND/PURPOSE

Neuroblastoma is a common pediatric tumor of the sympathetic nervous system. Unlike the ones found in older children, the tumors found in patients younger than one year of age often show spontaneous differentiation and regression. Peroxisome proliferator-activated receptor gamma (PPAR-gamma), a member of the nuclear hormone receptor superfamily is expressed in several human cancers. Recently, PPAR-gamma has been reported to be expressed in neuroblastoma, and the agonist of this receptor caused differentiation of neuroblastoma cells.

METHODS

In this report we studied the expression of PPAR-gamma mRNA, using LightCycler in neuroblastoma samples diagnosed in 17 patients under the age of one year.

RESULTS

Twelve samples showed PPAR-gamma mRNA expression. There was no significant difference in the PPAR-gamma mRNA expression based on age, histology, staging, and DNA ploidy. The PPAR-gamma mRNA expression level was significantly correlated with the change in urinary vanillyl mandelic acid (VMA). The neuroblastoma samples resected from patients who showed a decrease in their urinary VMA before the operation showed significantly higher PPAR-gamma expression than those from patients who showed an increase in their urinary VMA before the operation.

CONCLUSIONS

PPAR-gamma may have played a role in the reduction of VMA and possibly in the regression of early-onset neuroblastoma.

Alteration of mast cell proliferation/apoptosis and expression of stem cell factor in the regression of mastocytoma--report of a case and a serial immunohistochemical study

BACKGROUND

Spontaneous regression of solitary mastocytoma is a well-described phenomenon, but its mechanism is unknown.

METHODS

Serial-section immunohistochemical analyses were performed on biopsies of a mastocytoma from a Japanese child during the proliferation stage (PS, 7 months of age) and the regression stage (RS, 5 years old).

RESULTS

Mast cell (MC) density in RS was markedly decreased (406 cells/mm2) compared to that in PS (3554 cells/mm2). MCs in RS were larger than those in PS. With proliferative cell nuclear antigen (PCNA) staining, 1.7% MCs were positive in PS, whereas no positive MCs were seen in RS. TUNEL-labeling index (LI) in RS (2.8%) increased 1.5-fold in PS (1.9%). With stem cell factor (SCF) staining, 57% of lesional MCs in RS revealed strong cytoplasmic immunoreactivity, whereas only 9% of MCs were positive in PS. Epidermal SCF reactivity was found as intracellular and intercellular patterns in both PS and RS.

CONCLUSIONS

Loss of MC proliferating activity, an increase in apoptotic MCs, and increased expression of SCF in remaining MCs in RS may play a role in the involution of mastocytomas.

Study of the regression process in cardiac rhabdomyomas

Rhabdomyomas are the most common primary cardiac tumors in children, and have been shown to undergo spontaneous regression. The aim of our study was to investigate morphologically and immunohistochemically some mechanisms that may explain this clinical phenomenon. Eleven tumors from three term newborn girls who had physical and radiographic features pathognomonic of tuberous sclerosis were evaluated. Control specimens were left and right heart sections from five autopsies of age- and sex-matched patients who died of causes unrelated to the cardiovascular system. The tumors had been surgically excised from various regions in the heart, and all had similar "typical" histology. Histomorphologic evaluation with von Kossa and alizarin-red stains and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL) method were performed to evaluate cell calcifications, necrosis, and apoptosis. Ubiquitin immunohistochemical study was also conducted to evaluate intracytoplasmic protein degradation. In cardiac rhabdomyomas (CR), all myocytes with acidophilic cytoplasmic myofibrils showed strong intracytoplasmic ubiquitin immunoreactivity, compared with the occasional weak cytoplasmic and focal nuclear positivity in control heart sections. Calcified myocyte nuclei were commonly seen in CR tumoral and nontumoral rhabdomyocytes, whereas control nontumoral cardiac myocytes did not show any calcification. The incidence of TUNEL reactivity seen in CR (4.8 nuclei per 100 cardiac rhabdomyocyte nuclei) was higher than that seen in control heart sections (1.7 nuclei per 106 cardiac myocytes, P < 0.005). The data led us to conclude that the cytoplasmic contents in CR were degraded via the ubiquitin pathway, and from our observation of increased TUNEL positivity, the rate of cell death in CR appeared increased. These findings may explain, to some extent, the mechanism of tumor regression.

The natural history of disappearing bone tumours and tumour-like conditions

We describe 27 cases of bone tumours or tumour-like lesions where there was spontaneous regression. The follow-up period was 2.8-16.7 years (average, 7.0 years). Fourteen of these cases were no longer visible on plain radiographs. Histological diagnosis included exostosis, eosinophilic granuloma, fibrous dysplasia, fibrous cortical defect, non-ossifying fibroma, osteoid osteoma and bone island. Most cases began to reduce in adolescence or earlier, although sclerotic type lesions showed their regression in older patients. All lesions thought to be eosinophilic granuloma began to regress after periods of less than 3 months, while the duration of the other lesions showed wide variation (1-74 months). As resolution of the lesions took between 2 and 79 months (mean, 25.0 +/- 20.3 months) we consider that the most likely mechanism was recovery of normal skeletal growth control. In exostosis with fracture, alteration of vascular supply may contribute to growth arrest, but not to subsequent remodelling stage. In inflammatory-related lesions such as eosinophilic granuloma, cessation of inflammation may be the mechanism of growth arrest, whilst temporary inflammation may stimulate osteogenic cells engaged in remodeling. In the sclerotic type, growth arrest is a less probable mechanism. Necrosis within the tumour and/or local changes in hormonal control, plus remodelling of the sclerotic area takes longer. Knowledge of the potential for spontaneous resolution may help in management of these tumour and tumour-like lesions of bone.

Recurrent hepatocellular carcinoma after spontaneous regression

The prognosis of untreated hepatocellular carcinoma (HCC) is usually grave, although there have been a few case reports of spontaneous regression. Tumor recurrence after spontaneous regression has been rarely reported, and there have been no previous reports of recurrent hepatocellular carcinoma after spontaneous regression. Two cases of hepatocellular carcinoma that spontaneously regressed and subsequently recurred are presented. The patients' tumors spontaneously regressed, as reflected by the radiologically evidenced reduction in tumor size and markedly decreased alpha-fetoprotein levels. Subsequent tumor recurrences after regression were evidenced by radiologic findings of newly growing nodules and appreciably increased alpha-fetoprotein levels. To the authors' knowledge, these two patients represent the first reported cases of hepatocellular carcinoma recurrence after spontaneous regression. In both of these patients, new hepatocellular carcinomas recurred at different sites before the spontaneous regression of the original HCCs was complete. Although the precise causes of the regression and the subsequent recurrence remain to be further investigated, this phenomenon suggests that multicentric hepatocarcinogenicity and intratumoral events in each hepatocellular carcinoma nodule may be involved.

A murine B cell lymphoma expressing human HER2 / neu undergoes spontaneous tumor regression and elicits antitumor immunity

In the present study we describe a novel murine tumor model in which the highly malignant murine B cell lymphoma 38C13 has been transduced with the cDNA encoding human tumor-associated antigen HER2/neu. This new cell line (38C13-HER2/neu) showed stable surfiace expression but not secretion of human HER2/neu. It also maintained expression of the idiotype (Id) of the surface immunoglobulin of 38C13, which serves as another tumor-associated antigen. Surprisingly, spontaneous tumor regression was observed following s.c. but not i.v. injection of 38C13-HER2/neu cells in immunocompetent syngeneic mice. Regression was more frequently observed with larger tumor cell challenges and was mediated through immunological mechanisms because it was not observed in syngeneic immunodeficient mice. Mice that showed complete tumor regression were immune to challenge with the parental cell line 38C13 and V1, a variant of 38C13 that does not express the Id. Immunity could be transferred with sera, suggesting that an antibody response mediated rejection and immunity. Continuously growing s.c. tumors as well as metastatic tumors obtained after the i.v. injection of 38C13-HER2/neu maintained expression of human HER2/neu, which can serve as a target for active immunotherapy. As spontaneous tumor regression has not been observed in other human murine models expressing human HER2/neu, our results illustrate the enormous differences that can exist among different murine tumors expressing the same antigen. The present model provides a useful tool for the study of the mechanisms of protective immunity to B cell lymphoma and for the evaluation of different therapeutic approaches based on the stimulation or suppression of the immune response.

Spontaneous neoplastic regression: the significance of apoptosis

In mammalian cells, neoplastic transformation has a direct relationship with the expression of oncogenes, the production of certain growth factors and with the mutation, loss or simple inactivation of the function of tumor suppressor genes. Genes for suppression of the development of the malignant immunophenotype, as well as inhibitory growth factors have regulatory functions within the normal processes of cell division and differentiation. Telomerase (a ribonucleoprotein polymerase) activation is frequently observed in various types of neoplastic cell transformation. Telomerase activation is regarded as essential for cell immortalization and its inhibition may result in spontaneous regression (SR) of neoplasms. SR of neoplasms occurs when the malignant tumor mass partially or completely disappears without any treatment or as a result of a therapy considered inadequate to influence systemic neoplastic disease. This definition makes it clear that the term SR applies to neoplasms in which the malignant disease is not necessarily cured, and to cases where the regression may not be complete or permanent. A number of possible mechanisms of SR are reviewed, with the understanding that no single mechanism can completely account for this phenomenon. The application of the newest immunological, molecular biological and genetic insights for more individualized anticancer immunotherapy (biotherapy) is also discussed. In conclusion, of all the possible mechanisms of SR of neoplasms, programmed cell death (PCD) or apoptosis is involved in each. The immunological mechanism is probably the main effector mechanism of SR in human neoplasms with its trigger being apoptosis. The treatments of the tumor, such as with various anti-neoplastic drugs or radiation or immunotherapy, all include the basic mechanism of programmed cell death or apoptosis. Without apoptosis, there is practically no tumor regression, none of any kind.

A case of intravascular large B-cell lymphoma mimicking erythema nodosum: the importance of multiple skin biopsies

BACKGROUND

Intravascular lymphoma is a rare disease characterized by the proliferation of neoplastic monuclear cells within the lumens of small blood vessels. The neoplastic cells are usually of B-cell origin, and rarely of T-cell or histiocytic origin. Although this clinicopathological entity of lymphoma has not been listed in general pathological classifications such as REAL classification or the Working Formulation, it is recently in the WHO classification scheme, which is essentially an updated REAL scheme, and the EORTC classification scheme.

METHODS

In this report, a 62-year-old woman with intravascular large B-cell lymphoma was observed by clinical, histopathological, immunohistochemical and molecular methods.

RESULTS

A 62-year-old woman presented with large erythematous macules on the bilateral thighs and lower legs. The lesions were accompanied with hard, tender, intradermal or subcutaneous nodules mimicking erythema nodosum. Histopathological examination in the first biopsy revealed non-specific panniculitis compatible with erythema nodosum. The second biopsy revealed emboli of atypical lymphocytes within many of the dilated and proliferated vessels in the deep dermis and subcutaneous tissue. These cells were positive for L-26 and kappa light chain, and negative for lambda light chain, factor VIII-related antigen, CD30, CD34, CD68 and UCHL-1. These findings confirmed the diagnosis of intravascular large B-cell lymphoma. A laboratory examination showed a high level of LDH and abnormal cells in the bone marrow. An MRI of the brain and computed tomographic (CT) scans of the chest and abdomen revealed no evidence of malignancy. Before the treatment, the size of the nodules decreased spontaneously by about 50% in one month and significantly in two months. Although combination chemotherapy, which consisted of CHOP, brought her partial remission, she experienced neurological symptoms 6 months after the initial treatment and died of brain metastasis 9 months after the treatment.

CONCLUSIONS

This is a unique case for two following reasons: 1) the first biopsy revealed non-specific findings compatible with erythema nodosum; and 2) before the treatment, the nodules regressed spontaneously. Dermatologists should take multiple skin biopsies for EN lesions with the non-specific histopathological findings not to refute the existence of this disease.

Regressing Merkel cell carcinoma-a case showing replacement of tumour cells by foamy cells

Merkel cell carcinoma (MCC) is a malignant neuroendocrine tumour with a high rate of recurrence and metastasis. However, some cases of spontaneous regression have recently been reported. We describe the clinical course of an 80-year-old Japanese woman with regressing MCC. We also report histological findings of the regressing tumour for the first time. After the patient's first visit to our hospital, the lesion was a rapidly progressive tumour, but suddenly began decreasing in size, and rapidly regressed. The surface of the tumour flattened, the colour changed from red to dark red, and finally the lesion appeared as a small yellowish plaque. Histopathological analysis of the completely regressed tumour revealed that the tumour cells were completely replaced by numerous foamy cells. This is the first report demonstrating the histopathological features of regressing MCC.

Clinicopathologic study of mass-screened neuroblastoma with special emphasis on untreated observed cases: a possible histologic clue to tumor regression

Spontaneous regression and maturation of neuroblastoma (NB) are well documented and occur frequently in infants, including those detected by mass screening. To seek histologic clues for regression/maturation in mass-screened NB, clinicopathologic features of 12 tumors that were resected after 2 to 18 months of untreated observation were reviewed. Unobserved screened and age-matched unscreened patients were also studied. To evaluate the possible important role of apoptosis, apoptotic cells were detected by in situ deoxyribonucleic acid (DNA) nick end labeling and immunohistochemical stain for activated caspase-3. Nests with a varying degree of reduced cellularity ("less cellular" and "hypocellular" nests) were common in patients younger than 18 months of age, and were rare in older patients. Two characteristic cells, which have not been focused previously, were frequent, especially in the hypocellular nests. One showed amorphic eosinophilic cytoplasm with pyknotic nuclei and the other contained plump cytoplasm with well-maintained nuclei. These cells were also observed in 89% of the unobserved screened NBs and 79% of the age-matched unscreened patients with good outcome, whereas they could not be confirmed in any of the age-matched unscreened NBs with poor outcome. The amorphic and plump cells were negative for activated caspase-3 and in situ DNA nick end labeling. From these results, the authors hypothesize that these cells most likely represent a degenerative process, in either a state before the activation of caspase-3 or a caspase-independent form of cell death. The presence of less cellular and hypocellular nests with amorphic/plump cells may serve as one of the important clues in predicting tumor prognosis.

Spontaneously relapsing clonal, mucosal cytotoxic T-cell lymphoproliferative disorder: case report and review of the literature

Primary T-cell lymphoma of the gastrointestinal tract is a rare and usually aggressive disorder that may be associated with celiac disease. The authors describe a unique case of a clonal proliferation of CD8+ T cells involving the oral mucosa, ileum, and colon of a 35-year-old man that has regressed spontaneously and recurred numerous times over a 9-year period without treatment. The patient's symptoms were limited to occasional rectal bleeding and recurring painful oral ulcers. Within the intestine, these collections of small T cells induced minimal architectural distortions and did not show extensive epitheliotrophism. Polymerase chain reaction and sequencing analyses revealed that the identical T-cell clone has been present for more than 9 years and in different mucosal locations in this patient. This may represent a unique T-cell lymphoproliferative process akin to a mucosal counterpart of lymphomatoid papulosis of the skin.