Regarding the anatomical and physiological aspects of lithopedion, this article resolves to define lithopedion typologies and characteristics, investigate the circumstances under which lithopedion occurs, identify the commonality of lithopedion, recognize the symptoms of lithopedion for diagnosing living women, explore cases of lithopedion discovered in patients antemortem where extraction occurred, explore cases of lithopedion discovered in patients antemortem where no extraction occurred, and explore cases of lithopedion discovered in deceased women post mortem. Regarding the medicolegal aspects of ownership or custody of lithopedion, this article resolves to consider the ethical concerns in the extraction and disposition of lithopedion from living women, as well as in the removal and disposition of lithopedion from decedents.

Lithopedion presents in one of three typologies, occurs only in abdominal pregnancies, is an extreme rarity, and carriers are often asymptomatic. Carriers with symptoms have general indications that mimic a plethora of abdominal conditions. The majority of lithopedion discoveries are incidental and extraction is not always done. Lithopedion is discovered in females both antemortem and post-mortem.

In antemortem cases, lithopedion custody or ownership belongs to the woman from whom the lithopedion was derived and from whom it was surgically removed. In post-mortem cases, lithopedion custody or ownership belongs to the deceased female’s next of kin. As much as a surgeon or medical examiner may want to preserve the lithopedion as a wet or dry specimen for posterity and research purposes, and as scarce as lithopedion specimens are, these professionals must adhere to their code of ethics and the laws within the jurisdictions in which they practice.

The first recorded case of lithopedion dates as far back as 1100 BC and was discovered in the Bering Sinkhole (what is now known as Kerr County, Texas) during an archaeological excavation that recovered the “human remains of 62 individuals” [2]. One of these corpses was a long-deceased, unidentified female carrying a lithopedion within her. Documented cases have also been chronicled as recently as 2020 AD, including the latest case of Hawa Adan, who presented at Kenya’s Mandera County Referral Hospital for abdominal swelling. Adan received a CT scan, was promptly diagnosed with lithopedion, and had the calcified male fetus surgically removed after having been in her body for thirteen years. It was determined that Adan’s lithopedion was a result of an undetected abdominal pregnancy that occurred in 2007 [3].

The span between the most ancient case and the most recent modern-day case is 3119 years and 8760 miles, thus proving that the phenomenon of lithopedion is bound by neither time nor space. This makes it sufficient to assume that cases of lithopedion will not cease to occur in the future. Additionally, since lithopedion has been discovered in women’s bodies both antemortem and postmortem, both medical doctors who serve living female patients (internists, gastroenterologists, gynecologists, etc.) and medical professionals who serve female decedents (medical examiners, forensic pathologists, coroners, medico-legal death investigators, etc.) should familiarize themselves with this rare but continuous occurrence. Professionals should be aware of the rights of a living woman regarding her lithopedion, as well as the rights of the next of kin of a deceased woman regarding the decedent’s lithopedion.

It was not until the year 1880 that Friedrich Küchenmeister, a renowned German physician, reviewed the documentation on forty-seven cases of lithopedion. After reading these nearly four dozen confirmed cases from medical literature, he recognized a need for categorization. He then established three subgroups of lithopedion.

Küchenmeister named the first type Lithokelyphos, which means stone sheath, because in these cases calcification occurs on the placental membrane and not on the actual fetus. The amnion remains undamaged, and the fetus is not attached to it at all. Here, the amniotic fluid was reabsorbed by the woman’s body and the membranes became calcified. The fetus can be in a macerated or decomposed state, but is not actually calcified itself as shown in Figure 1. He named the second type Lithotecnon, which means stone child, because in these cases, “the fetus itself is calcified after entering the abdominal cavity, following the rupture of the placental and ovarian membranes.” Küchenmeister referred to the Lithotecnon as the true lithopedion. The third and final type, Küchenmeister named Lithokelyphopedion, which means stone sheath and child, because in these cases the fetus and the placental membrane have both been calcified [4].

Figure 1. Medical image of lithopedion from late 1800s [5].

Each lithopedion typology was characterized by Küchenmeister according to the anatomical portion(s) that had become petrified with calcium. This categorization is still referred to and utilized today with regard to the medical documentation of lithopedion cases worldwide.

All cases of lithopedion are a result of an undetected, extrauterine pregnancy. An extrauterine pregnancy, known as ectopic, is the “result of a flaw in human reproductive physiology that allows the conceptus to implant and mature outside the endometrial cavity, which ultimately ends in the death of the fetus” [6]. The vast majority of extrauterine pregnancies are tubal at around 95%. However, the small 5% of non-tubal, ectopic pregnancies do indeed transpire in other locations, including the cervix, ovary, and abdomen. Lithopedion has been found to occur regardless of the extrauterine implantation location, as specimens have been discovered throughout the abdominal cavity both within and outside of the female reproductive organs.

When a female patient incurs an extrauterine pregnancy, one of these three events will occur: 1) The ectopic pregnancy will be discovered, surgically removed, and disposed of as medical waste; 2) The ectopic pregnancy will not be discovered, but will be small enough for the patient’s body to absorb; and 3) The ectopic pregnancy will not be discovered, will grow too large to be absorbed by the woman’s body, and will calcify “as part of a foreign body reaction, shielding the mother’s body from the dead tissue of the fetus and preventing septic infection” [7]. The third event is the only circumstance under which lithopedion occurs, as long as the deceased fetus maintains sterility and is in a place in the mother’s body that is favorable for calcium deposition.

Lithopedion may occur from a gestation period of fourteen weeks to full term. If a woman remains asymptomatic, and if the lithopedion manages to escape medical detection, it is likely that it can stay undiagnosed for decades. This is why many cases of lithopedion discovery have been in post-menopausal women who were being medically examined for unrelated conditions that required abdominal x-rays. The average age of women being diagnosed with lithopedion is fifty-five years, with the eldest woman being one hundred years old. Statistically, lithopedions are carried undiscovered for an average of twenty-two years prior to detection. However, nine case studies identify women who carried lithopedion for over fifty years before receiving a diagnosis. Additionally, recorded cases exist in which women became pregnant while already unknowingly carrying a lithopedion, birthing healthy children without incident and without discovery of the lithopedion [8].

Lithopedion is an extremely “rare event that occurs in 0.0054% of all gestations” [9]. Additionally, only “about 1.5% - 1.8% of the abdominal babies develop into lithopedion” [10], showing that extrauterine pregnancies do not culminate in lithopedion in 98.2% - 98.5% of instances. These epidemiological statements on the quoted rates are derived from literature in both South African and international medical journals, evidence of rates persisting across the continents. Additionally, these rates are only indicative of instances of diagnosed lithopedion. Limitations exist in that not all lithopedion are discovered, as many females will live decades with a lithopedion, die with a lithopedion, and their body disposition will be carried out without ever having the lithopedion detected at all.

Lithokelyphos (stone sheath) has been found to be the most common type of lithopedion, and only around 300 cases including all lithopedion types have been documented since the year 1582. This is not to say that more do not exist, as there is no way to determine the following: 1) How many women are currently carrying lithopedion asymptomatically, 2) How many of these women will have their lithopedion diagnosed ante-mortem in the future, 3) How many of these women will die and have their final disposition carried out without the discovery of the lithopedion post-mortem, and 4) How many women throughout history have had their final disposition carried out without the discovery of their lithopedion post-mortem.

Lithopedion carriers often remain asymptomatic, either never discovering the existence of their lithopedion or being diagnosed accidentally as an incidental finding during an unrelated abdominal radiographical scan. Lithopedion is often discovered on plain abdominal X-rays, which show a radiopaque mass but cannot detect structures. When no imaging beyond X-rays is pursued, a lithopedion can be mistaken for calcified teratoma, leiomyomas, mesenteric lymph nodes, cholelithiasis, or even dystrophic calcification. It is only with a CT scan that a definitive diagnosis of lithopedion can occur, as the CT scan provides far superior detail. It allows doctors to confirm by visualizing fetal structures such as the skull, spine, and limbs within the calcified shell. Therefore, “a CT scan with 3D reconstruction is the gold standard for defining the anatomy of the calcified fetus, identifying its relationship with adjacent organs, and mapping any adhesions, which is essential for planning surgical removal” [11].

However, some lithopedion carriers do show symptoms, including a feeling of heaviness and/or pressure in the abdomen and having a palpable, hard mass in the pelvic region. Some women will complain of the “compression of organs (especially the urinary bladder or rectum)” [12]. This is on account of the size and location of the lithopedion, as additional symptoms, including bowel pain, chronic constipation, feelings of intestinal obstruction, and urinary tract issues, are also reported [13].

Women who are suffering from symptoms of lithopedion and dwell in westernized countries are more likely to follow medical advice and have abdominal scans administered, ultimately resulting in a diagnosis of lithopedion. Women in more underdeveloped regions are more likely to simply remain in a state of suffering with these symptoms on account of the lack of access to radiological healthcare technologies.

The cases in this section are all of either the lithokelyphos or lithotecnon typologies. All lithopedion mentioned in this section were carried from 8 years to 47 years. The clinical/forensic takeaway is that all of the lithopedion in this section expired in their third trimester of gestation and were of fully formed newborn maturity at the time of extraction.

A thirty-eight-year-old woman was found to have been carrying a lithopedion for eight years. Post-extirpation, the specimen was determined to be a fetus weighing 2.9 lbs. Portions of the greater omentum adhered to a surface shell, and when dissected, almost all of the internal organs were visible to the naked eye. It seemed as though “many parts of the fetus had undergone saponification, resulting in a whitish and fatty appearance” [14]. Radiological examinations revealed that this lithopedion’s bone measurements matched a gestational age of approximately 9 months.

A female patient was informed by her physician that her pregnancy was extrauterine and would not be fruitful, but she feared surgery and went home against medical advice. The woman regularly self-treated with home remedies for pain alleviation purposes, and within a few months the pain had ceased. Thirty-seven years later, at the age of sixty, the pain began again. At this time, “fearing cancer, she sought hospital treatment, was diagnosed and had the fetal remains extracted” [15].

A woman of eighty years presented at a hospital’s outpatient department with extreme pain in the abdominal region. Ultrasound screening exhibited an echogenic mass within the patient’s upper right quadrant. An x-ray was taken and the skeleton of a fully developed extrauterine fetus was discovered. “It is presumed from the patient’s history that this fetus was present for at least 40 years. Radiography revealed a fetus shrouded in a mantle of calcification. The fetus was hyper-flexed with other signs of ‘intrauterine’ death” [16]. The lithopedion, determined to be at 34 weeks gestation, having extensive calcification subcutaneously, viscerally, and intracranially, was subsequently surgically removed.

The cases in this section are all of the lithokelyphos or lithotecnon typology. All lithopedion mentioned in this section were carried for 40 to 60 years. The clinical/forensic takeaway is that all of the lithopedion in this section expired in either their second or third trimester of gestation and were partially developed or fully developed at the time of their discovery.

Within the abdomen of a ninety-one-year-old woman, a lithopedion was discovered during an x-ray examination at the hospital following a fall. Medical doctors determined the calcified fetus had been present in the woman’s body for sixty years, and it was so developed and large that it occupied the majority of the woman’s abdominal cavity. The patient stated that it sometimes hurt, but really just felt like an uncomfortable lump for all these decades. The medical team overseeing her care “considered surgery to remove the fetus but later determined that, in this case, operating on a 91-year-old patient was riskier than doing nothing at all” [17].

After experiencing extreme back pain during a known pregnancy, a woman sought a remedy from a local “healer” involving non-westernized medicine, who gave her a substance to end the pain. It worked, but the woman never delivered the baby. She assumed she had miscarried. Forty years later, at the age of seventy, the same woman was having abdominal pain and presented as a patient when doctors discovered the lithopedion. It was not extracted, as the woman refused to have the lithopedion removed [18].

A seventy-three-year-old woman often presented with a history of infected vaginal discharge. She was, as usual, treated for purulent inflammation of the cervix after the return of laboratory reports. The treatment for the condition resolved, but was followed, as it was in the past, by pain and breathlessness in the patient. Radiography was finally performed on the patient, revealing a lithopedion in her abdominal cavity. She was asymptomatic throughout her reproductive life, and the lithopedion was not removed for financial reasons [19].

The cases in this section are all of the lithokelyphos or lithotecnon typologies. All lithopedion mentioned in this section were carried for approximately 50 years. The clinical/forensic takeaway is that all of the lithopedion in this section expired in either their first or third trimester of gestation and ranged from somewhat-fledged to fully-fledged at the time of their discovery.

An autopsy report indicated a seventy-year-old female expired as a result of stenosis of the mitral valve and coronary ostium. The lithopedion was an incidental finding unrelated to the decedent’s demise. The uterine wall appeared to be thickened and the lithopedion was within the right portion of the Pouch of Douglas, embedded in connective tissue. The dead fetus was calcified and contained fetal structures including a spine, ilium, and ribs. The lithopedion was determined to be at a three-month gestational age [14].

An eighty-two-year-old woman died due to complications from pneumonia and had birthed seven children in her lifetime. Upon examination, it was determined that forty-nine years prior to her death, she became pregnant with number eight, which resulted in lithopedion. It was verified that for nearly fifty years before her death, the woman felt a “tumor” in her belly, but it never caused her pain and a doctor was never consulted about it. There was no link between her death and the lithopedion finding. Her lithopedion was found in the left iliac fossa, where its calcification was solid with the exception of some areas that had the consistency of dough. When the pathologist opened the “tumor”, a male fetus estimated to be eight gestational months was revealed. Granules of calcium were discovered throughout the fetal tissue. Radiology displayed humeri, a femur, and an ulna with measurements pointing to approximately 36 weeks of gestation prior to calcification [14].

The autopsy performed on a seventy-five-year-old woman who expired after a cerebral hemorrhage brought forth the discovery of her lithopedion, indicating she was correct all along while alive. In life, she had informed her doctor that fifty years ago, she became pregnant but never delivered the baby. She informed a hospital’s lead physician that she was carrying a petrified baby and had a hard mass in her abdomen. However, after examining the living patient, the medical doctor “considered the irregularity as a solid tumor of the internal genitalia and preferred not to intervene due to the advanced age and the physical conditions of the patient” [14]. After the woman’s demise, a hard mass draped in a leather-like membrane in the lower right abdomen was examined thoroughly. The mass was identified as a fetus in a curled, frank breech position. The lithopedion’s head was compressed, had hair, and ossified parietal bones were present. The lithopedion weighed 1.7 lbs. and had bone measurements corresponding to the final month of gestation” [14].

When a lithopedion is discovered and extracted from a living female patient, the surgeon will document the lithopedion’s size and location, send the lithopedion to the pathology lab, complete the closure of internal and external surgical incisions, and ensure aftercare is in place for the female patient. Measurements of the lithopedion’s fetal elements and characteristics to establish gestational age at its demise/calcification will occur within the pathology laboratory. The specimen will be preserved for study in medical museums for educational purposes due to its uncommonness and significance. Due to the rarity of the finding, the surgeon will create a case report to publish in medical literature to contribute to the scientific knowledge on the phenomenon.

A problem of legality and ethics is posed when a woman does not wish for her lithopedion to be processed and preserved for medical and educational posterity. While the same cannot be said of all nations, in the United States, patient rights have revolved around the ethical concept of autonomy and self-determination for more than fifty years. This was promulgated with the Patient’s Bill of Rights by the American Hospital Association (AHA) [20]. This publication by the AHA provided greater focus on the pronounced shift away from the practice of medicine as paternalistic. It brought greater recognition and acceptance of the patient as the decision-maker of healthcare decisions. This became a legal requirement under the doctrine of informed consent based on state laws throughout the United States. Failure to follow these laws may find the healthcare provider liable [21]. Dealing with a rare medical phenomenon, such as lithopedion, does not negate the duty of medical professionals to defer to patients on decisions of disposal of their own genetic material in the form of lithopedion. In other words, in the United States, the scientific world’s need for a lithopedion specimen for medical and educational posterity does not supersede a patient’s right to bury, entomb, or cremate the remains of her lithopedion in the same way a woman may choose to do so in the case of a stillbirth or miscarriage.

We must remember that the lithopedion is neither in the germinal stage nor in the embryonic stage, as it would have been absorbed by, expelled from, or removed surgically from the mother’s body if its demise occurred during weeks one through eight of prenatal development. Lithopedions are in the fetal stage, occurring during the prenatal development stage of fourteen weeks to full term. The only differences between a lithopedion and a stillborn are its location, the duration it remains within the mother’s body, and whether or not it becomes calcified. Lithopedions are outside the uterus, remain for years to decades within the female patient, and calcification occurs; stillborns are located within the uterus, remain in the woman’s body until induction or surgical removal, and are not calcified. Therefore, ownership and custody rules for surgically removed specimens in pathology practice must adhere to the same rights a female patient would be given if it indeed was a stillborn case.

A lithopedion is not a specimen in the same sense that a surgically removed tonsil is a specimen. The lithopedion had the potential to be a living being had it matured in the uterus rather than in an extrauterine abdominal location, as shown in Figure 2. While each state in the US has its own time frame regarding disposition rights for fetal remains/stillbirth losses, many follow that of the State of Texas. “If a stillborn or miscarriage is less than 20 weeks gestation or under 350 grams, the mother may opt to bury or cremate his or her remains through a funeral home. If the baby is greater than 20 weeks gestation or over 350 grams, the mother must bury or cremate his or her remains through a funeral home as required by Texas State Law” [22]. This framework will apply in a hospital setting should the lithopedion-carrying patient choose not to allow for the lithopedion to become a wet or dry specimen as an educational specimen to a science museum.

Figure 2. Radiological image of lithopedion published in 1897, two years after the invention of the x-ray in 1895 [23].

When lithopedion is exposed while conducting an autopsy of a female decedent, the pathologist will document the lithopedion’s size, location, measurements of fetal elements (like the femur), and characteristics in order to approximate its gestational age at calcification. Then, the medical examiner will make a determination on whether or not the lithopedion was a contributing factor to the decedent’s demise. In the vast majority of cases, the lithopedion is an isolated finding that has no impact on the female decedent’s cause of death. However, intestinal obstruction or an infected abscess within the abdomen could mean the lithopedion was a contributing factor to the death. After this determination is made, just as in antemortem cases, the specimen will be preserved for study in medical museums for educational purposes due to its uncommonness and significance. Again, as in antemortem cases, because of the rarity of the lithopedion, the pathologist will create a case report to publish in medical literature to contribute to the scientific knowledge on the phenomenon.

An issue of legal ethics is brought forth when a decedent’s next of kin does not wish for the decedent’s lithopedion to be processed and preserved for medical and educational posterity. Other nations aside, in the United States, the right of a woman’s next of kin to decide how to dispose of a lithopedion is also governed by the right of sepulcher. The right of sepulcher derives from common law and provides for the right of the next of kin to take immediate possession of any remains of the decedent [24]. Although all states recognize this right, not all states have codified it. Some states recognize the right based on court decisions. For example, this right is codified in New York State under the Public Health Law, 4201(2)(3) regarding disposition of remains [25]. The only justification for not following the right of sepulcher is if doing so would result in a hazard to the public or violate any requirements of the public health laws. There is no evidence in the medical literature that would indicate that allowing a decedent’s next of kin to bury, entomb, or cremate the lithopedion alongside the female decedent would pose a danger or hazard to the public. There is also no evidence in the medical literature that would indicate that allowing a decedent’s next of kin to bury, entomb, or cremate the lithopedion separately from the female decedent would pose a danger or hazard to the public. In view of that, respect for the rights of the decedent’s next of kin to govern the disposition of her genetic material should prevail, and this should become common knowledge among the pathologists employed at all medical examiner facilities.