Pacinian corpuscle hyperplasia: A review of the literature.

OBJECTIVE: Pacinian corpuscle hyperplasia typically presents as a tender nodule on the volar aspect of the palm or digit, often after trauma. Histologically, it presents as one to multiple normal-sized to enlarged Pacinian corpuscles in the deep dermis or subcutaneous adipose tissue. Given its rarity, its pathogenesis is debated and nomenclature is poorly defined. Herein, we present a case of Pacinian corpuscle hyperplasia and review the current literature.
METHODS: A literature review was conducted using PubMed with the following search terms: Pacinian corpuscle hyperplasia, Pacinian corpuscle neuroma, Pacinioma, Pacinian corpuscle hypertrophy, and heterotopic Pacinian corpuscles. All case reports and case series were reviewed for histopathologic evidence of true Pacinian corpuscle hyperplasia. Cadaveric studies, cases without true Pacinian corpuscles, and noncutaneous cases were excluded from our analysis.
RESULTS: Sixty patients with Pacinian corpuscle hyperplasia of the hands and feet (65 cases, some with >1 location) were reviewed. The mean age of presentation was 49.5 years, and women accounted for 60% of cases. Pain was the most commonly reported symptom (55 of 65 cases; 84.6%). Forty-five cases (69.2%) were localized to a digit, most commonly the second digit (17 of 65 cases; 26.2%), and 18 of 65 cases (27.6%) affected the palm, primarily the distal palm. Surgical excision was curative in 50 of 65 cases (76.9%).
CONCLUSION: Although relatively uncommon, Pacinian corpuscle hyperplasia should be considered in the differential diagnosis of a tender nodule on the digit or distal palm, particularly after trauma.

Introduction

Pacinian corpuscles, also called Vater-Pacini or lamellar corpuscles, are rapidly adapting mechanoreceptors that respond to changes in pressure and vibration (Gartner, 2017, Vijayaraghavan et al., 2008). Discovered by Vater in 1741 and first described histologically by Pacini in 1835 (Cauna and Mannan, 1958), Pacinian corpuscles are most often localized to the deep dermis (Quindlen et al., 2015). They are also found in the subcutaneous tissue, the heart, breasts, joints, and mesentery and loose connective tissue (Rhode and Jennings, 1975). Pathology involving Pacinian corpuscles is rare.

Terminology within the literature is inconsistent. Pacinian corpuscle hyperplasia describes a pathologic increase in the size (also called Pacinian hypertrophy) and/or density of mature Pacinian corpuscles. The term Pacinian corpuscle hyperplasia is used interchangeably with Pacinian neuroma and Pacinioma (Fassola et al., 2019, Imai et al., 2003). However, it is distinguished from Pacinian neurofibroma, which is composed of structures resembling Pacinian corpuscles at various stages of development with variable degrees of Schwann cell proliferation (Friedrich and Hagel, 2019). Given their rarity, Pacinian neuroma and Pacinian neurofibroma have been mistakenly conflated; therefore, Pacinian neurofibroma will not be reviewed herein. In this report, we describe a case of Pacinian corpuscle hyperplasia and review the literature to raise awareness for this condition.

Case

A 69-year-old female patient with a medical history of acute myeloid leukemia (AML) and granulocytic sarcoma in remission presented with a 1-week history of a painful nodule on the right second finger. Her history of AML was complicated by multiple relapses, but she did not have neuropathy. Treatment included bone marrow transplant and chemotherapy. She had a granulocytic sarcoma on the right upper thigh that had regressed 1 year earlier after treatment with radiation and decitabine.

Physical examination was significant for a firm, mobile, 1-cm, flesh-colored subcutaneous nodule on the volar aspect of the right second finger proximal phalanx (Fig. 1). There were no epidermal changes observed on dermoscopy. A 5-mm punch biopsy was performed to rule out metastasized granulocytic sarcoma. During the biopsy, small grape-like clusters were noted in the subcutaneous tissue and were excised.

Fig. 1

Clinical examination showing painful, firm, mobile, flesh-colored, subcutaneous nodule, 1 cm in diameter, on the volar aspect of the proximal phalanx of the right second finger.

Histopathology with hematoxylin and eosin staining showed a single enlarged Pacinian corpuscle within the adipose tissue, surrounded by normal nerves and blood vessels in the interstitial stroma (Fig. 2, Fig. 3). A diagnosis of Pacinian corpuscle hyperplasia was rendered.

Fig. 2

Histological appearance of Type A Pacinian corpuscle neuroma showing a single enlarged corpuscle with several adjacent normal corpuscles (hematoxylin and eosin staining with 4× magnification).

Fig. 3

Histological appearance of single enlarged Pacinian corpuscle (hematoxylin and eosin staining with 20× magnification).

At follow-up 2 weeks later, the pain had subsided and there was no evidence of a residual nodule. In a telephone follow-up 2 months later, the patient reported no recurrence or associated pain. Six months later, she had an AML relapse, followed by subsequent cerebrovascular attacks, and died.

Literature review/discussion

A normal Pacinian corpuscle measures 1 to 2 mm by 0.1 to 0.7 mm in the skin but up to 5 mm in other organs (Gartner, 2017, Reznik et al., 1998). It is composed of a central core containing an unmyelinated nerve terminal, surrounded by multiple concentric fibrous lamellae (normally 13–15 lamellae; Fraitag et al., 1994) and an outer capsule, continuous with the perineurium (Cauna and Mannan, 1958, Imai et al., 2003). Macroscopically, it has been described as a cluster of rice-like, gray-white, ovoid bodies. In a cadaveric study of 10 subjects, there were a mean of 300 (192–424) Pacinian corpuscles in the hand, distributed near the digital nerves in the fingers (44%–60%), near the metacarpophalangeal joints (25%–48%), and in the thenar and hypothenar regions (8%–18%; Stark et al., 1998). Maximum normal density is 3 to 5 corpuscles per square centimeter (Lang-Stevenson, 1984, Yan et al., 2006).

Pacinian corpuscle hyperplasia was first described by Patterson in 1956 in a 33-year-old woman who presented with a bilateral enlargement of the distal pulp of her thumbs. On surgical exploration, a gross excess of Pacinian corpuscles was discovered and a diagnosis of Pacinian neuroma was made (Patterson, 1956). In 1975, Rhode and Jennings proposed an anatomical classification of these benign tumors into four subtypes: Type A (a single, enlarged, subepineural corpuscle); Type B (a grape-like cluster of normal-sized Pacinian corpuscles attached to the digital nerve by a fine filament), Type C (a series of slightly enlarged corpuscles arranged in tandem beneath the epineurium, appearing as a branch to the nerve), and Type D (hyperplastic Pacinian corpuscles arranged along the entire length of a digital nerve, each single or paired corpuscle attached to the nerve by a fine nerve fiber; Rhode and Jennings, 1975).

The Rhode and Jennings Pacinian corpuscle hyperplasia classification was both described as sensible and criticized as difficult to apply without a detailed account of the surgery (Fletcher and Theaker, 1989). In 1998, Reznik et al. suggested that Types C and D could be grouped together, simplifying the classification system to three subtypes: Type 1 (a single, enlarged Pacinian corpuscle), Type 2 (a cluster of normal-sized Pacinian corpuscles), and Type 3 (a cluster of enlarged Pacinian corpuscles; Reznik et al., 1998). Both classification systems are currently used to describe Pacinian corpuscle hyperplasia.

The differential diagnosis for a painful cutaneous tumor is broad and includes calcinosis cutis, leiomyoma cutis, eccrine spiradenoma, neuroma, Morton’s neuroma, dermatofibroma, tufted angioma, angiolipoma, neurilemmoma, granular cell tumor, glomus tumor, angioendotheliomatosis, metastases, hidradenoma, osteoma cutis, fibromyxoma, blue rubber bleb nevus, leiomyosarcoma, eccrine angiomatous hamartoma, Dercum’s disease, piezogenic papule, thrombus, scar, and keloid (Bhat et al., 2019, Cohen et al., 2019). All these pathologies have been reported in the hands and feet, but only glomus tumor, fibromyxoma, eccrine angiomatous hamartoma, piezogenic papules, and Morton’s neuroma are commonly localized to the hands or feet. Pacinian corpuscle hyperplasia can be distinguished clinically from some of these entities, with its presentation as an isolated flesh-colored nodule on the volar surface of the distal palm or digit; biopsy with histopathology is necessary for confirmation. Given our patient’s history of AML and granulocytic sarcoma, metastasis was also considered.

In addition to our case, 60 patients with Pacinian corpuscle hyperplasia of the hands and feet have been reported (Table 1). Cadaveric studies and cases without true Pacinian corpuscles were excluded from our analysis. The mean age of patients at the time of presentation was 49.5 years (range, 17–88 years) with a female predominance (37 of 61 patients; 60.7%; Table 2). Four patients (Lang-Stevenson, 1984, Patterson, 1956, Pickrell et al., 2019, Rhode and Jennings, 1975) presented with Pacinian corpuscle hyperplasia in >1 location (n = 65 cases). Similar to our case, the majority presented with a tender digital nodule. Forty-five cases (69.2%) were localized to a digit, most commonly the second digit (17 of 65 cases; 26.2%), and 18 of 65 cases (27.6%) affected the palm, primarily the distal palm (Fig. 4).

Table 1

History, physical examination, and outcomes of Pacinian corpuscle hyperplasia cases.

Paper	Diagnosis	Age, y	Sex	Site	Reznik class	Jennings class	Trauma	Pain	Mass	Sensory change	Resolved with excision	Other association
Patterson, 1956	PC neuroma	33	F	First digit bilaterally	2, 3	B	No	N	Y	N	UNK	Computer operator
Zweig and Burns, 1968	Nerve compression by subepieneural PCs	42	F	Web space	1	A	Yes, local	Y	N	N	Y
Zweig and Burns, 1968	Nerve compression by subepieneural PCs	54	M	Distal palm	1	A	Yes, local	N	Y	Y	Y
Hart et al., 1971	Hyperplastic PCs	66	F	Second digit	3	B, D	Yes, distant	Y	N	N	Y	Heat and cold sensitivity; pain radiating to shoulder
Sandzen and Baksic, 1974	Pacinian hyperplasia	59	F	Distal palm	2	B	Yes, local	Y	Y	N	Y
Sandzen and Baksic, 1974	Pacinian hyperplasia	21	M	Third digit	2	B	None	Y	Y	N	Y
Rhode and Jennings, 1975	PC neuroma	44	M	Distal palm in two locations	1,2,3	A, B, C	Yes, local	Y	Y	Y	Y
Cameron, 1976	Hyperplasia of a PC	17	F	First digit	1	A	None	Y	N	Y	UNK
Kojima et al., 1977	PC hyperplasia	50	F	Palm	2	B	Yes, local	Y	UNK	UNK	Y	Glomus tumor; required multiple surgeries
Schuler and Adamson, 1978	Pacinian neuroma	47	F	Second digit	2	B	None	Y	Y	N	Y
Schuler and Adamson, 1978	Pacinian neuroma	55	M	Fifth digit	2	B	Yes, local	Y	N	N	Y
Tsuchida et al., 1979	PC hyperplasia	36	F	Palm	2	B	None	Y	UNK	UNK	Y
Gama and Mattosinho Franca, 1980	Nerve compression by PCs	35	F	First digit	2	B	None	Y	Y	N	Y	Bone insufflation on roentgenogram
Gama and Mattosinho Franca, 1980	Nerve compression by PCs	23	F	Distal palm	3	B, but enlarged PCs	Yes, local	Y	Y	Y	Y
Chavoin et al., 1980	Proliferation of PCs	51	M	Third digit	3	D	Yes, local	Y	Y	N	Y	Required multiple surgeries
Greider and Flatt, 1982	Pacinian hyperplasia	69	M	Second digit	3	B, but enlarged PCs	Yes, local	Y	Y	Y	Y	Glomus tumor; heat and cold sensitivity
Yasunaga et al., 1933	PC hyperplasia	72	M	First digit	2	B	None	Y	UNK	UNK	Y	Glomus tumor
Friedman et al., 1984	Subepineural PC	18	F	Second digit	1	A	Yes, local	Y	N	N	Y	Pain radiating to elbow
Lang-Stevenson, 1984	PC hyperplasia and hypertrophy	60	M	Third and fourth digits	3	UNK	None	N	N	N	N/A	Incidental finding
Brynildsen, 1985	Subepineural PC	33	F	Fourth digit	1	A	Yes, local	N	N	Y	Y
Umemoto et al., 1988	Pacinian hypertrophy	28	F	First digit	3	C	UNK	Y	Y	N	UNK
Umemoto et al., 1988	Pacinian hypertrophy	22	M	Second digit	3	C	UNK	Y	Y	N	UNK
Fletcher and Theaker, 1989	Pacinian neuroma	33	F	First digit	2	B	None	Y	Y	N	Y	Progressive enlargement since birth
Fletcher and Theaker, 1989	Pacinian neuroma	44	F	Second digit	2	B	Yes, local	Y	Y	N	Y	Pain radiated to elbow
Fletcher and Theaker, 1989	Pacinian neuroma	54	M	Web space	2	B	Yes, local	Y	Y	N	UNK
Jones and Eadie, 1991	PC hyperplasia	55	F	Distal palm	2	B	Yes, distal	Y	Y	Y	Y
Fraitag et al., 1994	PC hyperplasia	70	M	Third digit	3	B but enlarged PCs	None	Y	N	Y	UNK	Locksmith
Kojima, 1992	PC hyperplasia	41	F	Palm	2	A, B, D	None	Y	UNK	UNK	Y
McPherson and Meals, 1992	PC neuroma	59	M	Second digit	2	B	None	Y	Y	N	Y	Erosive changes to bone on x-ray
Bas et al., 1993	Hyperplastic PC	47	F	Fifth digit	1	A	None	Y	N	N	Y	Pain radiating to arm
Calder et al., 1995	Nerve compression by hyperplastic PCs	68	F	Distal palm	2	B	Yes, local	Y	Y	N	Y	Trigger finger
Reznik et al., 1998	Hyperplasia and hypertrophy of PCs	63	F	Second digit	3	B but enlarged PCs	None	Y	Y	N	Y
Reznik et al., 1998	Hyperplasia and hypertrophy of PCs	44	M	Third digit	3	B but enlarged PCs	Yes, local	Y	N	N	Y
Akyurek et al., 2000	PC hyperplasia	87	F	Distal palm	2	B	None	N	N	N	N/A	Dupuytren's contracture
Rinaldi et al., 2000	Pacinian hyperplasia	62	M	First digit	2	B	Yes, local	Y	Y	N	Y
Satge et al., 2001	Pacinian hyperplasia	66	F	Toe	3	C	None	Y	N	N	Y
Kumar et al., 2003	PC hyperplasia	65	F	Toe	3	UNK	None	Y	N	N	Y	Morton's tumor
Kumar et al., 2003	PC hyperplasia	32	M	Fifth digit	2	B	None	Y	N	N	Y
Vaes and De Smet, 2003	Subepineural PC	33	F	Second digit	1	A	None	Y	Y	N	Y
Kuruvila et al., 2003	Pacinian neuroma	17	F	Web space	2, 3	ND	Yes, local	Y	Y	N	Y
Imai et al., 2003	PC hyperplasia	67	M	Fourth digit	2	B	Yes, local	Y	Y	Y	Y
Marini et al., 2004	Pacinian neuroma	UNK	F	Second digit	UNK	UNK	UNK	UNK	UNK	UNK	Y
Narayanamurthy et al., 2005	PC neuroma	88	F	First digit	3	B but enlarged PCs	None	Y	Y	N	Y
Kenmochi et al., 2006	Pacinian neuroma	57	F	Third digit	1, 2	A, B	Yes, local	Y	N	N	UNK
Yan et al., 2006	PC hypertrophy	24	F	Fourth digit	3	UNK	none	Y	Y	Y	Y	NF1
Vijayaraghavan et al., 2008	PC hyperplasia	45	F	Second digit	3	B but enlarged PCs	Yes, local	Y	Y	N	Y
Yenidunya et al., 2009	PC hypertrophy	55	F	Second digit	1	A	Yes, local	Y	N	N	Y	2A burn contracture
Yenidunya et al., 2009	PC hyperplasia and hypertrophy	72	M	Palm	3	UNK	None	N	Y	N	N/A	Dupuytren's contracture
Irie et al., 2011	Heterotopic PC	24	M	First digit	1	A	None	Y	N	N	Y	1 × 1.5 mm
Irie et al., 2011	Heterotopic PC	31	M	Distal palm	2	B	None	Y	N	Y	Y
Cho et al., 2012	Pacinian neuroma	45	F	First digit	3	UNK	Y	Y	Y	N	Y
Von Campe et al., 2012	Pacinian neuroma	74	M	Distal palm	3	UNK	None	Y	N	N	Y	Dupuytren's contracture
Zech et al., 2013	Mystery case	34	M	First digit	2	B	Y, local	Y	N	N	UNK	Painter
Garcia et al., 2015	PC hyperplasia and hypertrophy	50	F	Second digit	3	B- but enlarged PCs	Yes, local	Y	Y	N	UNK	Required multiple surgeries
Komforti and Cummings, 2015	Pacinian hyperplasia	65	F	First digit	3	C	Yes, local	Y	N	Y	Y	Glomus tumor
Mahipathy et al., 2015	Pacinian neuroma	34	F	Fifth digit	2	B	None	Y	Y	Y	N	Congenital (pain resolved, not neuropraxia)
Garrido-Colmenero et al., 2016	Pacinian neuroma	75	M	Second digit	3	B- but enlarged PCs	None	Y	N	N	Y	Osteolysis on radiograph
Jimenez et al., 2017	PC hyperplasia/neuroma	71	M	Second digit	UNK	B, D	None	Y	Y	N	Y
Pickrell et al., 2019	PC hyperplasia	61	M	Second and third digits	2, 3	D	None	Y	N	N	Y	CREST syndrome; severe Raynaud’s; pianist
Friedrich and Hagel, 2019	Vater-Pacini neuroma	54	F	Fifth digit	2	B	None	Y	N	N	N	NF1
Present case	PC Hyperplasia	69	F	Second digit	2	B	UNK	Y	Y	N	Y	History of acute myeloid leukemia

F, female; M, male; N/A, not applicable; N, no; NF1, neurofibromatosis type 1; PC, Pacinian corpuscle; UNK, unknown; Y, yes.

Table 2

Summary of demographics of Pacinian corpuscle hyperplasia cases.

Demographic characteristics		n (%)
Patients, N = 61	Mean age, y	49.5
	Male	24 (39.3)
	Female	37 (60.7)
Anatomic location, N = 65	Palm	4 (6.2)
	Distal palm/web space	14 (21.5)
	First digit	13 (20.0)
	Second digit	17 (26.2)
	Third digit	7 (10.8)
	Fourth digit	3 (4.6)
	Fifth digit	5 (7.7)
	Toes	2 (3.1)
	Two locations*	4 (6.2)
Patient history and examination characteristics, N = 65	Pain	55 (84.6)
	Prior trauma	28 (43.1)
	Mass	34 (52.3)
	Sensory change	13 (20.0)
Reznik subtype, N = 65	1	9 (13.8)
	2	24 (36.9)
	3	22 (33.8)
	Multiple†	8 (12.3)
Jennings subtype, N = 65	A	9 (13.8)
	B	34 (52.3)
	C	4 (6.2)
	D	3 (4.6)
	Multiple‡	6 (9.2)
Surgical intervention, N = 65	Resolved with excision	50 (76.9)
	Required >1 surgeries	3 (4.6)

Cases with 2 locations included index and middle finger, ring and middle finger, bilateral thumbs, and 2 areas in the distal palm.

Cases with multiple Reznik subtypes included pairings of 1,2; two 1, 2, 3; and five 2,3.

Cases with multiple Jennings subtypes included pairings of a, b; a, b, c; a, b, d, and two b, d.

Fig. 4

Distribution of Pacinian corpuscle hyperplasia in the hands and feet.

Pain was the most common symptom, reported for 55 of 65 nodules (84.6%). Tenderness was described in 17 cases; other descriptors included throbbing, severe, acute, and burning. Thirty-four patients (52.3%) had a mass or swelling, and 13 (20.0%) presented with sensory changes. The most common Reznik subtypes were Type 2 (36.9%) and Type 3 (33.8%). The most frequent Jennings subtype was B (52.3%), consistent with an earlier review (Fassola et al., 2019). Nine of the 33 cases designated as Jennings subtype B were enlarged rather than normal sized, as traditionally stated. Two cases could not be discerned from the description provided as a specific Reznik class, and 9 were not discernable for Jennings classification. Additionally, one case (Irie et al., 2011) presented as a normal-sized subepineural Pacinian corpuscle that caused pain; it was included as Type 1/A despite technically belonging to neither class.

The pathogenesis of Pacinian corpuscle hyperplasia remains to be elucidated, but prior trauma has been implicated as a potential cause. Injury has been hypothesized to disrupt the blood flow of the arteriovenous anastomoses located in close proximity to Pacinian corpuscles, resulting in the formation of new corpuscles (Cauna and Mannan, 1958, Imai et al., 2003, Jimenez et al., 2017). Our findings of a predilection for the right first three digits in close proximity to the digital nerves and metacarpophalangeal joints (Fig. 4) supports the theory of repetitive trauma leading to hyperplasia of preexisting Pacinian corpuscles. In our review, 43.1% of cases were associated with prior trauma. Work-related exposure to repeated microtraumas has been proposed as a potential risk factor in the case of a locksmith (Fraitag et al., 1994); this reasoning is applicable to cases reviewed of a painter (Zech et al., 2013), computer operator (Patterson, 1956), a woman who experienced repetitive needling trauma from her work with fabrics (Cho et al., 2012), and a pianist (Pickrell et al., 2019). Other associated findings were glomus tumor (4 cases; Greider and Flatt, 1982, Kojima, 1992, Komforti and Cummings, 2015), Dupuytren’s contracture (3 cases; Akyurek et al., 2000, Von Campe et al., 2012, Yenidunya et al., 2009), and neurofibromatosis (2 cases; Friedrich and Hagel, 2019, Yan et al., 2006). Pacinian corpuscles in the fascia of patients with Duputryen’s disease are larger and stain more intensely for nerve growth factor compared with Pacinian corpuscles in the hands of control patients (Ehrmantant et al., 2004). Burn contracture (Yenidunya et al., 2009) and Raynaud’s (Pickrell et al., 2019) were described in one case each. To date, no cases have been associated with hematologic malignancy or immunosuppression as seen in our case.

Surgery is the mainstay of treatment for Pacinian corpuscle hyperplasia. Surgical excision resulted in resolution of symptoms in 50 cases (76.9%). However, three cases (Chavoin et al., 1980, Garcia et al., 2015, Kojima, 1992) required multiple surgeries to control symptoms due to hyperplastic Pacinian corpuscles found in >1 location along the nerve. In only one case (Mahipathy et al., 2015), the patient reported ongoing symptoms after excision in which pain resolved but neuropraxia persisted.

Conclusion

The case presented is a classic example of the clinical and histological presentation of Pacinian corpuscle hyperplasia. Although rare, it should be considered in the differential diagnosis of a tender nodule on the digit or distal palm, particularly after trauma. This case, along with previous reports, helps clarify diagnostic terminology and subtype classifications.

Conflicts of Interest

None.

Funding

None.

Study Approval

The author(s) confirm that any aspect of the work covered in this manuscript that has involved human patients has been conducted with the ethical approval of all relevant bodies.